Effect of grazing pressure on vegetation structure of Mongolian rangeland

Transcription

1 Doctoral Dissertation Effect of grazing pressure on vegetation structure of Mongolian rangeland September, 2013 Jambal SERGELENKHUU Graduate School of Environmental and Life Science (Doctor`s course) OKAYAMA UNIVERSITY 1

2 CONTENTS CHAPTER 1 INTRODUCTION 1. Climate 1.1. Seasons in Mongolia Geographical change in climate condition Vegetation Researches on effect of pastoralism on steppe vegetation Nomadic Pastoralism of Mongolia Condition of Rangeland of Mongolia Livestock of Mongolia Modern pastoralism of Mongolia Degradation of rangeland Changes on vegetation by overgrazing Objectives. 13 CHAPTER 2 MATERIALS AND METHODS 1. Study area Study sites Plant functional type (PFT) Meteorological data Sampling design and collected data Data analysis 20 CHAPTER 3 WEATHER CONDITION 1. Weather condition during the experimental period.28 2

3 1.1 Seasonal changes Yearly changes Geographycal changes Difference among sites...30 CHAPER 4: VEGETATION STRUCTURE 1. Species composition Plant functional types and palatability Geographycal changes Study site classification Dominant species Grazing effects on vegetation structure Suppressed area and endmost area Geographical difference Suppressed area Endmost area Annual changes Suppressed area Endmost area.49 CHAPTER 5 GRAZING PRESSURE 1. Grazing gradient from winter camp Types of spatial change in vegetation coverage Negative relationship Positive relationship Independent relationship.70 3

4 2.4 Temporal relationship Species of each relationship Dominant species Negative relationship Positive relationship Independent relationship Temporal relationship PFT of each relationship Negative relationship Positive relationship Independent relationship Temporal relationship 73 CHAPTER 6 THE KEY INFORMANTS`s EVALUATIONS 1. Species characteristics of several important plants Dominant shrubs Caragana microphylla as a nurse plant Artemisia frigida Artemisia adamsii Dominant grasses Stipa krylovii Leymus chinensis Cleistogenes squarrosa Agropyron cristatum Achnatherum splendens.86 4

5 1.3. Dominant herbs Carex spp Allium spp Chenopodium acuminathum Geographical variation The north and south zone Transit zone The mortality of livestock during dzud.90 CHAPTER 6 DISCUSSION AND CONCLUSION 1. Why were winter camps selected for study sites? The pastoralists` strategy Species composition PFT Life form Shrubs Grasses Herbs Palatability Shrubs Grasses Herbs Grazing effect in regional scale Species composition and dominant species in north and south zone Dominant species changes from north to south zone.96 5

6 7. Temporal changes in grazing effect Grazing effect in local scale Other discussions Shift of species composition Shift from caespitose to rhizomatous After the secession of land use Countermeasure to grazing In species composition Effect of site condition (nutrient) Tolerance for grazing Suppressed area and endmost site..104 CONCLUSION..109 Grazing Management in rangeland of Mongolia 109 ACKNOWLEDGEMENTS 111 REFERENCES 112 APPENDIX..118 Appendix Appendix

7 CHAPTER 1: INTRODUCTION 1. Climate 1.1. Seasons in Mongolia The climatic condition of Mongolia is a relatively dry with longed time days and much precipitation in summer and little snowfall in winter. As shown in Figure 1, the mean monthly temperature exceeds 0 C from April to October in the center of Mongolia, Ulaanbaatar. Especially from June to August (summer), the mean temperature ranges 18~26 C with 40 C of the maximum (AIACC, 2006) and about 65-80% of the annual precipitation occurs in these three months promoting plant growth throughout Mongolia. About two thirds of all precipitation and almost all growth of vegetation take place during May to September. In April and May (spring), however, strong wind of high temperature and low precipitation dries out soil and inhibits plant growth resulting very harsh condition for livestock. On the other hand, September and October are warm autumn with small rainfall. The mean monthly temperature from November to March (winter) is below 0 C and less than 5~10% of the annual precipitation. Small amount of snow fall covers the ground with less than 15~20 cm depth in average throughout winter because of very low air temperature exceeding -40 C in night (AIACC, 2006) and hides fodder from livestock Geographical change in climate condition Average annual air temperature ( C) at Ulaanbaatar ( `N, `E), Mandalgobi ( `N, `E) and Dalanzadgad ( `N, `E) is -0.6, 0.7 and 3.8 C and average annual precipitation (mm) is 293.2, and mm, respectively (Fujita, 2012), which indicates gradual changes in climate condition from cold and wet in north to hot and dry in south. According to such climate gradient, vegetation changes from forest to dry steppe via steppe as shown in Figure 2. 7

8 2. Vegetation The Mongolia is divided into six vegetation zones (montane, taiga forest, forest steppe, steppe, dry steppe and desert steppe) (Yunatov, 1976) which account for 3.0%, 4.1%, 25.1%, 26.1%, 27.2% and 14.5% of territory, respectively (Hilbig, 1995). In generally these vegetation zones distribute from north to south corresponding with the changes in precipitation as shown in Figure.2. Except montane zone, almost all grassland covering million ha are used for rangeland for nomadic production by pastoralist with 50 million heads of livestock. In the Mongolian natural rangeland, 2823 vascular plant species of 662 genera, 128 families have been recorded (Gubanov, 1993). The maximum biomass of pastures in montane, steppe and dry steppe is 0.5~0.8, 0.3~0.4 and 0.1~0.3 tons/ha respectively (Tserendashi, 2000). The Mongolian steppe is one of the last relatively undistributed areas of the steppe ecosystem that once covered a large part of the Eurasian continent (Hilbig, 1995). It is semi-open vegetation consisting of grasses, sedges, and frequently dwarfs shrubs. Generally the steppes occur on gentle slopes and plains with a deep loamy soil and good drainage (Staalduinen, 2005). Xerophytic vegetation is a characteristic feature of the steppe zone. The Mongolian steppe is different from other steppe zones dominated by shrubs and sub shrubs such as Caragana and Artemisia. Fertile carbonated and non-carbonated black and sandy soil prevails in this zone. Saline soil is found along depression and channels as well. 3. Researches on effect of pastoralism on steppe vegetation The study of spatial distribution of plants in Mongolia was started at early 18 th century (Messerschmidt, 1724). The first vegetation map of Mongolia was reported by Simukov (1935). Yunatov (1946) partly improved it and published with scale 1:1.5 million. The most fundamental vegetation formation of Mongolia was described in it. In this period, Mongolian botanists started to analyse pasture structure and productivity (Bandragcz, 1970; Tserenbaljid, 1972; Dashnyam, 1974 and Davaajamts, 1977). From early 1950`s, seasonality of pastural productivity and sowing efficiency of pasture were analyzed (Kalinina, 1954; Miroshnichenko, 1967) and morphological analysis of pastoral plants was performed by Grubov (1955, 1982). The importance of palatability of perennial grasses and forbs were identified to adopt the suitable species for modern pastoralism (Dashnyam, 1974; Erdenejav, 1976; Davaajamts, 1988). Tserendash (1996) started to analyze the resilience of pasture ecosystem under cultivation and 8

9 grazing and Chognii (1990) revealed resilience of natural pasture than cultivated pasture. 4. Nomadic Pastoralism of Mongolia More than 80% of Mongolian territory is used for pasture. Mongolian pastoralist doesn t use fixed settlement but adopts nomadic life using encampment of ger to move for yearlong to reach suitable fodder, water and safety shelter for livestock. As mentioned before, Mongolia has distinguished 4 seasons and pastoralists can adapt well to such seasonal changes (Konagaya, 2005) using irregular pattern of movement to maintain the nomadic production, mobility is the essential trait of pastoralism in Mongolia, which is noteworthy for seasonally changing and concurrently using encampments, and long range migration under extreme harsh winter to make it across the border of normal rangeland area into otor area (later describe in detail). Winter camp is established in a mountain recess leaning slightly (0~8%) and facing south-east to avoid strong and cold north-west wind. Livestock are moving over a wide area to avoid the concentration of grazing activity on a certain area which induces site degradation. Therefore, most of pastures suffer the same degree of degradation by heavy grazing pressure except the area around a winter camp. High degree of mobility is not only a passive reaction to the natural environment but also an effective measure to maintain natural resource (Sambuu, 1945; Fujita, 2003). However, in recently, winter camps are getting near to their convenience such as electricity, market, school and etc. 4.1 Condition of Rangeland of Mongolia Nomadic pastoralism in Mongolia adopted from more than 5 thousand years which means that such nomadic production is suitable to adapt seasonal changes in weather condition. However, current climate changes have to ask such traditional production system to arrange in several aspects of mobility. Although the seasonal shift of settled pasture is the essential technique of nomadic pastoralism, the way of movement is still not theoretically managed and largely depends on pastoralist s ability and his experiments (Simukov, 1935). Most of pastoralists select the suitable place in summer season by the availability of water and grass. These two factors mainly control their movement (Yunatov, 1954). There are two types of migration such as a short distance migration (normally less than 100km) during growing season and a long distance shift of pasture occurred before and after winter to secure safety shelter. The immediate causes of the first type short migration are the avoidance of 9

10 pasture degradation by overgrazing and the demand of special element such as salt (Tomortogoo, 1983). The frequency of such shifting settlement is normally 1 or 2 times in forest steppe but becomes more in dry steppe because of low productivity (Denisov, 1946). The second type long migration is divided into two types into transmits to winter camp where pastoralist uses normally and emergency evacuation, otor, to a special reserved pasture to avoid unusually low temperature in winter. Otor is a very important grazing strategy referred to rapid movement of livestock over 15~20 km away from main camp with only a few pastoralists. Otor is vital for the livestock to gain weight and increase productivity. It is also ecologically important in order to prevent pasture degradation and to balance between grazing pressure and pasture`s carrying capacity. Otor areas established by government can accept 50~100 thousand heads of livestock in average. 4.2 Livestock of Mongolia Pastoralists keep five kinds of animals, namely camel, cattle, horse, sheep and goat, in rangelands from the montane to desert steppe. Although most of livestock have gotten relatively stronger stress tolerance for environmental stresses through both natural selection and artificial breeding for long years, a large number of livestock die under harsh environment in winter with heavy snow and strong wind. Since the change of Mongolian economic structure from socialistic control to free market economy in 1990, livestock numbers started to increase rapidly and had reached 45.3 million heads in 2009 (National Statistical Office of Mongolia, 2009) as shown in Figure 3. Sheep. The Mongolian sheep has adapted to the climatic conditions due to squared and small body size, fat tail, robust, good development of muscles and bones, and straight legs. The average weight of slaughter weight is 23.5 kg and yield is 48.1%. A ram, ewe and yearling produce 1.52 kg, 1.23 kg and 1.0 kg of wool, respectively. Ewes produce milk for days in June and July. Goat. Goats are well adapted to diverse environmental conditions and relatively prolific. They can climb up steep and rocky slope and pluck out short grasses growing in a space among rocks because of their shape of hoot pointed muzzle and thin and mobile lips. Therefore goat effect on environmental conditions much more seriously than other kinds of livestock. However, the number of goats doubled during 1990`s because of great demand of cashmere (National Statistical Office of Mongolia, 2003). About 3 thousand tons of cashmere produced in Mongolia annually. Cattle. The Mongolian cattle is small in body size but about 66.9~113.6 thousand tons of beef are produced annually, and 12.9~14.0 thousand tons are exported. 10

11 Horses. Mongolian horse is also small in body size, but has deep square chest, well-developed bones and muscles. They are bred for riding, draught and racing. They can survive harsh condition and produce meat and milk. Camels. A majority of the camel lives in Gobi region. 4.3 Modern pastoralism of Mongolia Traditionally, pastoralists migrate seasonally with their livestock through the open pasture to find good fodder. Most pastoralists look after specific livestock, such as horse pastoralist or cattle pastoralist. The pastoralists who look after horse and camel must stay far from pastoralists with small livestock. Many special techniques were developed in traditional pastoralism mostly depending on the natural condition including vegetation and climate. To protect their livestock from harsh weather in winter, many pastoralists construct livestock barns at their winter camp sites, which were often located at the foot of a mountain, facing south, to avoid strong wind. Before socialism, society consisted of small number of wealthy nomads and large number of poor nomads (Vreeland, 1957). With the onset of the socialism, livestock were gradually gathered to the ownership union. By such modernization program, the pastoral production system changed from a household industry supporting individual family to an important national scale industry come under the herding sector. Traditional nomadic pastoralism using several unfixed encampments in growing season and fixed winter camp was organized by socialist government for both from individual and national scale management. For example, before the socialism, pasture for emergency excavation in severe winter was mainly conserved by mutual agreement among restricted local pastoralists which brought frequent severe struggle. But socialist government established a large scale shelter pasture for otor and managed it sustainably. From 1960 to 1990, industrialization of pastoralism including new provision of livestock transport system, settled shelter (pen), fences for grassland protection, veterinary services, macinally wells for water supply, delivery system of supplementary fodder and etc. resulted a rapid growth of livestock number from 14 million to 37 million (Konagaya, 2003). The market economy newly introduced in Mongolia affected the pastoralists livelihoods. As most of Mongolian concentrated around the capital city for their convenience, pastoralists 11

12 (one-third of the population) were living sparsely over a vast of territory with a great number of livestock. However, the level of infrastructures including road system, communication facilities, electricity and ect. were far inferior from the demand of modern commercial transaction. 4.4 Degradation of rangeland Causes of pasture degradation are summarized as follows (Tserendash and Tserendeleg, 2000): 1. Natural causes such as drought, flood and soil erosion. 2. Overgrazing by massive gathering of pastoralists to central zone. 3. Cultivation of pastureland and make it fallow. 4. High density of road network. 5. Mechanic centralization due to decrease in number of drilled wells. 6. No responsibility exists for law enforcement of land, nature conservation and pasture related laws and regulations which lead to new areas at risk of degradation and conflicts. Overgrazing has the biggest cause for land degradation. But in comparison with the present heads of livestock (45.3 million) and the carrying capacity of Mongolian rangeland (60-70 million) (Jigjidsuren and Johnson, 2003), there is still a room to allow much more development of animal husbandry. Because of new economic system introduced in 1990, pastoralists show a tendency to aggregate around big cities, such as Ulaanbaatar, or main route which make them easy to sell and transport livestock and by-products and to access social services. High grazing pressure in these areas seriously disturbs rangeland ecosystem and causes significant changes in vegetation structure. Over exploitation of above and belowground biomass by heavy grazing for long period induces indispensable degradation of rangeland ecosystem and also decrease in carrying capacity. When the overgrazing continues over a long time and is repeated yearly, the physiognomy and species composition of pasture vegetation are changed by degradation. 4.5 Changes on vegetation by overgrazing Pasture degradation by overgrazing was found especially around sites where livestock gathered, such as water sites (Stumpp et al, 2005), livestock camps (Sasaki et al, 2008) and Sum (town in Mongolia) centers. Changes in plant community structure by grazing are strongly depending on plant life-form and its palatability (Stenberg et al, 2000). Plant functional type (PFT) is the nonphylogenetic groupings of species showing close similarities in their response to abiotic and biotic factors including grazing pressure (Lavorel et al, 1997; Smith et al, 1997). Therefore 12

13 PFT has been widely used for quantitative evaluation of the response of plant community to environmental disturbances. The vegetation degradation process is generally characterized by changes in dominant PFT in the community such as gradual increase in abundance of annual species with a concomitant decrease in perennial species under heavy grazing (Mclntyre and Lavorel, 2001; Pakeman, 2004; Diaz et al, 2007). Several studies in Mongolia have also reported such changes (Fernandez-Gimenez and Allen Diaz, 1999, 2001; Sasaki et al, 2005, 2007). 5. Objectives This study aims to reveal the sustainability of pastoralism in the north-central Eurasian grassland. In order to achieve the aim, assessment of the impacts of grazing pressure on rangeland vegetation structure was performed by geographical and local scales in the central Mongolia from steppe to dry-steppe. So, the main objective is to clarify the effect of grazing pressure on vegetation structure of rangeland in Mongolia. In order to carry out this objective to clarify: 1. The effect of grazing on vegetation structure around winter camp (local scale) 2. Geological differences in vegetation structure due to climatic differences (regional scale), and their temporal (year to year) variations. 13

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17 CHAPTER 2: MATERIALS AND METHODS 1. Study area As shown in Figure 4, a large typical steppe zone is extending from the east end to the middle of Mongolia, and is expanding to the north along Tuul river. Therefore, the center of Mongolia is the most suitable part for the study to clarify the grazing effects on the plant community of the typical steppe zone with a great variety of climate condition. Then the typical steppe zone from the northern end in central Mongolia (Darkhan city, N ; E ) to the southern end (Mandalgobi, N ; E ) was selected as the study area of this field survey (Figure 4). It consists of three provinces, Darkhan Uul, Tov and Dundgobi. Grazing pressure increased recently in some parts of pastures of Tov province, because of the concentration of pastoralists around the capital locating only 200km east from Tov province. 2. Study sites From 36 winter camps established in pasture dominated by Caragana shrub, which is the typical widely dominated shrub indicating dry steppe condition, twenty-one winter camps (Figure 4) were selected in 2009 for the study sites according to the following criteria. 1. Similar topography such as vast flat plain with easy slope around low relief knoll, 2. Similar period of use and 3. Similar composition of livestock (dominated by sheep). Location of these winter camps and nearest meteorological stations (Darkhan, Hustai, Zuunmod, Bayan Onjuul, Adaatsag and Mandalgobi with numbered 1-6, respectively) were shown in Figure 4. Most of selected winter camps were located in a slightly leaning recess near mountain ridge and faced south-east to avoid strong cold wind. From No.1 to No.12 winter camps were established on a gentle slope of hillside (Figure 5a). No.13 and above winter camps were in a lowland of large plain as illustrated in Figure 5b (redrawn from Nachinshonhor, 2008). Soil type of most winter camps was the typical Kastanozems (Haase, 1983). Location of each study site was measured by GPS (GARMIN, GPSmap 60CS). From the interview with the owner and neighbor(s) in 2009 and 2010, information about 17

18 winter camps, such as duration period of rangeland occupation by the winter camp and their livelihood were collected. Locations in latitude, longitude and altitude, administrative (name of Sum and province) and name of owner, the vegetation character of each winter camp were shown in Table 1 and Appendix 1 in detail. Table 2 shows the heads of each kind of livestock and these numbers were converted into sheep heads and shown in the right end column, according to the equivalent coefficients of sheep used by the National Statistical Office of Mongolia, such as 7, 5, 6 and 0.9 for horse, camel, cattle and goat, respectively. 3. Plant functional type (PFT) Identification of plant species name and its life form (plant functional type; PFT) such as shrub, herb and grass of perennial or annual were followed by Yunatov (1976), Grubov (1982) and Ulziikhutag (1985). Life form Shrub is distinguished from a tree by its multiple stems and shorter height, usually less than 1 m. Grass is the dominant vegetation in many habitats. Many types of animals eat grass as their main food. The meristem locates near the bottom of grass and it is effective for quick recovery after cropping of the top. Most of shrub and grasses are perennial and some of herbs are annual plant. Herb`s flowering period is early summer. Annuality A perennial plant can live for more than two years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials. Perennials, especially small flowering plants, that grow and bloom over the spring and summer, die back every autumn and winter, and then return in the spring from their root-stock, are known as herbaceous perennials. Many perennials produce relatively large seeds, which have an advantage with larger seedlings. Some annual plants produce many seeds in one season to secure the establishment of the next generation. While some (polycarpic) perennial plants are not under such pressure to produce large numbers of seeds but can produce seeds over many years. 18

19 Palatability These plants in pasture must have some tolerance for grazing by chemical countermeasures. Such plants are unpalatable and free from grazing pressure. On the other hand, quality and quantity of palatable plants are very important for livestock production. Palatability was classified into five categories, namely preferred, desirable, undesirable, not consumable and toxic (Jigjidsuren and Johnson, 2003; Damiran, 2005). Plant sought by particular livestock as a major diet and consumed far in excess was classified into preferred (P), plant readily eaten but less portion than preferred plant was classified into desirable (D), plant eaten as minor diet was undesirable (U). Moreover, plant not eaten intentionally, and plant with toxic substances were classified into not consumable (N) and toxic (T), respectively. These five categories were grouped into two groups of palatable (P+D) and unpalatable (U+N+T). 4. Meteorological data Six meteorological stations (Darkhan, Hustai, Zuunmod, BayanOnjuul, Adaatsag and Mandalgobi) shown in Figure 4 were selected from N `, E to N `, E ` (Table 3). 5. Sampling design and collected data The field survey was carried out in the growing season (from July to October) in 2009, 2010 and Three parallel lines were set from the center of the winter camp and seven plots were established along each line at 25, 50, 100, 200, 400, 800 (suppressed area) and 1600m (endmost area) from the origin, the winter camp (Figure 6). Total number of plots was 441 (3 lines x 7 plots x 21 winter camps). Four subplots were put within each plot as shown in Figure 6. Ground coverage (%) and the maximum height (cm) of each species were recorded at four subplots in each plot; resulting 1764 subplots (441 plots x 4 subplots) were surveyed at each winter camp. 19

20 6. Data analysis Classifications of 144 plots at each winter camp and 21 winter camps were performed by cluster analysis (TWINSPAN; Hill. 1979b) using PC-ORD for Windows ver.3.0 (McCune and Mefford, 1997) with species composition and its coverage. Factors affecting difference in plant community structure were analyzed by ANOVA in relation with site location and distance from winter camp. 20

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28 CHAPTER 3: WEATHER CONDITION 1. Weather condition during the experimental period Monthly mean temperature and amount of precipitation of 6 meteorological stations are shown in Figure 7 for 4 census years. 1.1 Seasonal changes As the average trend of weather condition, a seasonal change of climate at Hustai National Park was shown for four years in Figure 8. Mean air temperature increased from 2.4 o C (March) to 8.3 o C (May) at the beginning of spring, but total precipitation per month remained at very low level almost as same as winter season until the beginning of summer. Precipitation falls mainly in summer, renewing the soil moisture supply. In June, rainfall exceeded 70 mm/month and mean air temperature increased to 15.8 o C. In autumn, the mean temperature decreased from 8.9 o C (September) to o C (November) while precipitation decreased from 10.7mm to 3.6mm in these two months, respectively. The mean temperature fluctuated between the o C and o C in winter from December to February. The mean annual temperature and total precipitation were 3.1 o C and 20.7 mm, 16.3 o C and 81.2mm, -1.5 o C and 9.1mm and o C and 2.2mm in spring, summer, autumn and winter in 2009, respectively. The mean annual temperature and total precipitation were -1.0 o C and 9.2 mm, 17.3 o C and 72.9mm, 0.9 o C and 3.6 mm and o C and 2.5mm in spring, summer, autumn and winter in 2010, respectively. The mean annual temperature and total precipitation were 0.8 o C and 8.3 mm, 16.8 o C and 67.7 mm, -0.2 o C and 10.6 mm and o C and 2.2mm in spring, summer, autumn and winter in 2011, respectively. 1.2 Yearly changes 28

29 The period of growing season with air temperature higher than 13.8 o C was five months (from April to August) in every year of this experimental period as shown in Figure 8. In this growing season, total amount of precipitation was 161.8mm (84.9% of total annual precipitation), 189.6mm (81.5%), 167.0mm (81.8%) and 198.9mm (82.8%) from 2008 to 2011, respectively. Seasonal changes in air temperature were relatively stable among 4 years but remarkable variation was observed in temporal distribution of precipitation. The lowest amount of precipitation was in 2008 (190.4mm) and highest was in 2011 (240.3mm). The minimum air temperature was recorded during census year in January 2009, o C and the maximum temperature observed in July 2009, 36.8 o C. The annual temperature range was 72.2 o C, 76.5 o C, 81.7 o C and 73.4 o C in 2008, 2009, 2010 and 2011, respectively. 91.1%, 89.5%, 90.5% and 85.5% of annual precipitation occurred in a growing season from 2008 to 2011 then resulting hot and wet summer and cold and dry autumn, winter and spring. To evaluate weather condition from both temperature and humidity, the Kawakita-Kira s aridity-humidity index (AH) (Kira, 1977) was calculated by the following equation. AH= P W+20 (W 100) Where P is the total amount of precipitation and W is the average air temperature. AH indicates the weather condition of rainforest, forest, savanna, steppe and desert as more than 10, 10-7, 7-5, 5-3 and less than 3, respectively (Kira, 1977). As shown in Figure 9, AH did not show any difference among four years and the mean of AH, 3.1, indicated steppe condition. 1.3 Geographical changes The average air temperature and total precipitation of six meteorological stations were shown in Figure 10 and Figure 11, respectively. From north to south, the total precipitation decreased gradually, as the maximum value, 344.0mm in the north end site, Darkhan, to the minimum value, 99.1mm in the south end site, Mandalgobi. On the other hand, the average air temperature showed steep increase toward south from Hustai and Zunmod (-0.7 ~ -0.9 o C) except the north end 29

30 montane site, Darkhan. However, the mean air temperature in a growing season shown in Figure 12 was almost the same level for 6 stations. In the north end site, it was C and it increased from C (Hustai) to C (Mandalgobi), while annual precipitation slowly decreased from 53.7 mm (Darkhan) to mm (Mandalgobi). In this period, more than 82.5% of annual precipitation was recorded throughout six meteorological stations for four years in Figure 13. AH index (Figure 9) showed a different trend from both air temperature and precipitation. From the north end, Darkhan to the center, Zuummod, AH index remained almost the same level, around 4 with the maximum value 5.1 in Darkhan which indicated the border between savanna and steppe. However, it decreased drastically less than 3 in Bayan Onjuul showing the north hedge of desert condition. 1.4 Difference among sites The AH index in 2009 was 3.8, 5.0, 4.3, 2.6, 1.9 and 1.0 in Darkhan, Hustai, Zuunmod, Bayan Onjuul, Adaatsag and Mandalgobi, respectively (Figure 9). While AH index was 4.6, 4.1, 3.8, 1.8, 2.3 and 1.2 in 2010 and 5.1, 4.1, 4.4, 3.3, 2.4 and 1.5 in 2011, respectively. Yearly variations for 3 years were 2.3, 0.9, 1.0, 2.0, 0.4 and 0.5 respectively from north to south, which mean higher variation in the northern area than in the southern area. Especially in middle part of study area showed very high variation of climate condition which can vary from wet northern area to dry southern area. As shown Figure 10, the AH index was decreased from Hustai (5.0) to Mandalgobi (1.0) through geographical trend but in most north place (Darkhan) the index was 3.8 thenincreased from Hustai in However, this index slowly decreased from Darkhan (4.6) to Mandalgobi (1.2), but it perceptible decreased in Bayan Onjuul in Trend of this index from Darkhan (5.0) to Mandalgobi (1.5) slowly decreased but perceptible decrease in this trend was observed in Hustai. It shows that the extreme climate condition and of central Mongolia. 30

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41 CHAPTER 4: VEGETATION STRUCTURE 1. Species composition Ninety-five species of 60 genera and 26 families were recorded throughout 21 study sites in four census years as shown in Table 4. Among 26 families, both Compositae and Graminae had the largest number of species (15) comprising 15.8% of the total species number, and more than half of species (53.6%) were belonging to the top five families including Leguminosae, Rosaceae and Chenopodiaceae (Table 5). However, the total vegetation coverage of these families showed 53.7% (15.8%, 15.8%, 8.4%, 7.4% and 6.3% of Compositae, Graminae, Leguminosae, Rosaceae and Chenopodiaceae, respectively). Among 60 genera, 14 genera were the dominant group of genus comprising 54.3% of species number. Above all, Artemisia was the largest genus in species number (9) and also showed the highest value of vegetation coverage (10%). Among 95 species, 12 species, namely Caragana microphylla, Artemisia frigida, Stipa krylovii, Agropyron cristatum, Leymus chinensis, Achnatherum splendens, Cleistogenes squarrosa, Artemisia adamsii, Carex spp., Allium spp., Peganum nigelastrum and Chenopodium acuminathum, were the dominant species throughout the study area. Biology and photograph of these species were shown in Appendix Plant functional types and palatability Ninety-five species were classified into three plant life forms, namely 9 species as shrub, 15 species as grass and 71 species as herb as shown in Figure 14. Compositae and Graminae had 15 species and Leguminae had 8 species. Rosaceae and Chenopodiaceae had 7 and 6 species 41

42 respectively. As shown in Table 5, 51 species of these top five families were classified into 3 plant life form, mainly 7 species for shrub, 15 species for grass and 29 species for herbs. The life form of all species which occurred in study area in census years was shown in Appendix 3. As shown in the Table 5, all species of Graminae were grass, Rosaceae and Chenopodiaceae was herb. On the other hand Compositae and Leguminae contained shrub and herb. According to 3 life form, 2 annuality and 2 palatability, all plant species can classified into 12 groups (Table 6), that is called as PFT (plant functional type) in this research (Figure 15). As shown in Table 6, annual shrub is conflict classification. Then the PFT in this research is 10 that are perennial palatable shrub, perennial unpalatable shrub, perennial palatable grass, perennial unpalatable grass, annual palatable grass, annual unpalatable grass, perennial palatable herb, perennial unpalatable herb, annual palatable herb and annual unpalatable herb. All grasses (15 species) were palatable. But only 4 and 16 species from 9 shrubs and 71 herbs were palatable and more than half of them (5 shrubs and 46 herbs) were unpalatable. The rest 9 herbs were unknown for their palatability. As shown in Figure 15, palatable and unpalatable species could be classified into 7 categories, such as palatable shrub(4), palatable perennial grass(13), palatable perennial herb(15), palatable annual herb(1), unpalatable shrub(5), unpalatable perennial herb(34) and unpalatable annual herb(12). Three of four palatable shrubs were Caragana (C. microphylla. C. stenophylla and C. leucophylla and another palatable shrub were Artemisia frigida. The average coverage of these palatable shrubs was 2.1% (4.1%, 0.1%, 0.1%), and 0.01%, respectively. Four and three species of 13 palatable perennial grass were Stipa (Stipa krylovii, S. baicalensis, S. klemenzii and S. sibirica) and Poa (Poa botryoides, P. attenuata and Poa spp.), respectively. The total amount of vegetation coverage of palatable species was 13.0% in average of 21 study sites, and more than 15.2% of the rangeland was covered by unpalatable and unknown species. The most dominant unpalatable PFT was herb, including Artemisia (Artemisia adamsii, A. mongolica and A. scoparia), Thalictrum (Thalictrum petaloideum, Th. foetidum and Th. simplex), Potentilla (Potentilla acaulis, P. bifurca and P. viscosa) and Urtica (Urtica cannabina and Urtica sp). 42

43 3. Geographical changes 3.1 Study site classification By the TWINSPAN cluster analysis with the floristic composition of study sites combining all 1746 subplot data into the representative species composition of each winter camp, 21 winter camps were classified into several groups with a key species shown in Figure 16. In 2009 (Figure 16a), No.1 to No.10 winter camps belonged into one group with a representative specie of Heteropapus hispidus and Leymus chinensis, and other winter camps over No. 11 were classified into another group. The former 10 winter camps were located in northern part of steppe and the rest of them were in southern area. Almost the same classification was resulted in 2011 (Figure 16c) except for No.2 winter camp. The representative species of this classification was also Heteropapus hispidus. However, in 2010 (Figure 16b), three winter camps (No.7, No.8 and No.9) which belonged to the northern group in other years were classified into the group of southern winter camps over No.11. From these results, the location of border line between two major clusters was shifting in accordance with yearly fluctuation of weather condition (Figure 17), especially the total amount of precipitation. As a result, 21 winter camps were clustered into three major parts, such as north, south and transit zones, according to their geographical location as shown in Figure 17. The width of the transit zone was about 90km. All species name in these three zones (north, transit and south) were listed up in Appendix 4. The general descriptions of vegetation in 3 zones were shown in Table 7. During census years, 82, 51 and 49 species were recorded in north, transit and south zones, respectively. But, only a part of them could identify their palatability as shown in Table7 with number of total species within 74, 49 and 43 of these species were possible to determine the PFT in north, transit and south zones, respectively. As comparison of PFT among 3 zones, in north zone the percent of PFT`s were 5.4, 5.4, 17.6, 16.2, 43.2, 1.4 and 10.8% in shrub perennial palatable, shrub perennial unpalatable, grass perennial palatable, herb perennial palatable, herb perennial unpalatable, herb annual palatable and herb annual unpalatable, respectively. In transit zone, there were 6.1, 8.2, 16.3, 16.3, 36.7, 2.0 and 14.3% in shrub perennial palatable, shrub perennial unpalatable, grass perennial palatable, herb perennial palatable, herb perennial unpalatable, herb annual palatable and herb annual unpalatable, respectively while in south zone were 7.0, 7.0, 18.6, 18.6, 39.5 and 9.3% in shrub perennial palatable, shrub perennial unpalatable, grass perennial palatable, herb perennial palatable, herb perennial unpalatable and herb annual unpalatable, respectively. The herb annual palatable species wasn t occurred in south area. 43

44 3.2 Dominant species Dominant species in the north zone were Chenopodium acuminathum (13.9%), Artemisia frigida (5.5%), Caragana microphylla (4.7%), Artemisia adamsii (2.2%) and Leymus chinensis (2.0%) as shown in Table 8. In the transit zone, Artemisia adamsii (17.4%), Carex pediformis (5.0%), Caragana microphylla (2.8%), Leymus chinensis (2.5%) and Chenopodium acuminathum (2.4%) and in the south zones, Chenopodium acuminathum (9.7%), Caragana microphylla (4.1%), Allium Mongolichum (2.4%), Achnatherum splendens (1.9%) and Salsola collina (0.2%) dominated. Among these dominant species, Caragana microphylla and Chenopodium acuminathum were common in three zones, and Artemisia adamsii and Leymus chinensis were dominate in the north and the transit zones. The 66.7% and 33.3% of the number of dominant species in the north zone were palatable and unpalatable, respectively. While the total coverage of palatable and unpalatable species was 38.5% and 61.5%, which suggested species diversity of unpalatable plants were higher in the north zone than palatable plants. The species recorded only in the north, the transit and the south zones were shown in Table 9, namely, seventeen, five and four species were peculiar species, respectively and 19 species (one shrub, 13 grasses and 5 herbs) of these 26 species were unpalatable, while rest of one shrub, 2 grasses and 4 herbs were palatable. Five species (Stipa baicalensis, S. sibirica, Rhapontichum uniflora, Potentilla acaulis and Goniolimon speciosum) and two species (Allium Mongolichum and Peganum nigelastrum) were recorded in all census years in north and south zones, respectively. Stipa baicalensis, S. sibirica grasses and another 5 species are herbs. 4. Grazing effects on vegetation structure 4.1 Suppressed area and endmost area To analyze the effect of grazing pressure on vegetation structure, 18 (6 x 3) subplots located within 800m from the winter camp were considered as the vegetation growing under livestock grazing (noted as suppressed area) and 3 subplots at 1600m from the winter camp could represent the natural vegetation structure without heavy grazing (endmost area). 44

45 As shown in Table 10, 77 species of 51 genera and 22 families were recorded in the suppressed area, while 52 species of 37 genera and 16 families were recorded in the endmost area from all study area in three census years. Among 77 species in the suppressed area, 4, 5, 10, 15, 32, 1 and 10 species were perennial palatable shrub, perennial unpalatable shrub, perennial palatable grass, perennial palatable herb, perennial unpalatable herb, annual palatable herb and annual unpalatable herb, respectively. Among 52 species in the endmost area, 3, 1, 10, 8, 22, 1 and 7 species were perennial palatable shrub, perennial unpalatable shrub, perennial palatable grass, perennial palatable herb, perennial unpalatable herb, annual palatable herb and annual unpalatable herb, respectively Geographical difference Table 11 shows PFT composition of the north and south zones. In the suppressed area, 72 and 43 species were recorded in the north and the south zones and in the endmost area, 51 and 32 species were recorded in the north and the south zones, respectively Suppressed area Among 72 species in the north zone, 30 (0.1%), 12 (0.3%) and 9 (0.3%) species were unpalatable perennial herb, palatable perennial grass and palatable perennial herb, respectively. Seven unpalatable annual herbs (1.5%), 4 palatable shrub (2.3%), 3 unpalatable shrub (0.6%), 1 unpalatable annual herb (0.0%) and 6 species (0.1%) were impossible to determine palatability. Among 43 species in the south zone, 15 (0.2%), 8 (0.1%) and 7 (0.3%) species were unpalatable perennial herb, palatable perennial herb and palatable perennial grass, respectively. Five (0.3%), 3 (0.6%), 3 (0.0%) and 2 (0.0%) species were unpalatable annual herb, palatable shrub, unpalatable shrub and impossible to determine the palatability, respectively (Table 11). The total number of species in suppressed area was higher in north than south zone. In both zones, the number of species of unpalatable perennial herbs is high, but the average coverage was very low between 0.1 and 0.2% in north and south, respectively. Palatable grass species was not so different between north (9 species) and south (8 species) zones but the average coverage of them 0.3% and 0.1% in north and south, respectively. The number of palatable shrub species were 4 (2.3%) and 3 (0.6%) in north and south, respectively. The number of unpalatable shrub species 45

46 wasn t different in both zones but the average coverage of them was 0.6% and 0.0% in north and south zones, respectively. Unpalatable annual herb`s number was 7 and 5 but, the average coverage of them was 1.5% and 0.3% in north and south zones, respectively. The dominant species in the suppressed area of the north zone were Leymus chinensis, Artemisia frigida, Artemisia adamsii, Carex spp, Stipa krylovii and Chenopodium acuminathum. While Caragana microphylla, Achnatherum splendens, Allium Mongolichum and Chenopodium acuminathum dominated in the south zone. Table 12 shows the result of two-way analysis of variance for the coverage of each dominant species in suppressed area between the north and the south zones. Excepting Caragana microphylla dominated in both the north and the south zones, all dominant species showed significant difference of their coverage between the north and the south zone. Artemisia frigida showed higher coverage in the north (4.5%) than the south zone (0.4%). Stipa krylovii and Agropyron cristatum distributed throughout whole study area, but the coverage decreased significantly from north to south. Cleistogenes squarrosa, and Leymus chinensis could dominate only in the north zone. Stipa krylovii, Achnatherum splendens, and Artemisia adamsii could grow in all study sites but coverage was higher in the north than the south zone. Carex spp showed higher coverage in the north than the south zone. Allium Mongolichum was growing only in the south zone with high yearly variation caused by the change of precipitation. Chenopodium acuminathum were different in m from center of winter camp along from north to south. Peganum nigelastrum occurred with low coverage near the centre of winter camp only in the south zone Endmost area Among 51 species in the north zone, 22 (0.2%), 11 (0.2%) and 10 (0.6%) species were unpalatable perennial herb, palatable perennial herb and palatable grass, respectively (Table 10). Three (4.7%) palatable shrub, 2 (0.5%) unpalatable shrub, 2 (0.2%) unpalatable annual herb and 1 (0.0%) palatable annual herb were recorded in endmost area in north zone. Among 32 species in the south zone, 11 (0.1%) unpalatable perennial herb, 7 (0.1%) palatable perennial herb, 5 (0.5%) palatable perennial grass, 3 (1.5%) palatable shrub, 2 (0.0%) unpalatable shrub, 1 (0.4%) unpalatable annual herb and 3 (0.1%) of them were impossible to determine the palatability (Table 11). The total number of species in endmost area was higher in north than south zone. In both zones, the number of unpalatable perennial herb was highest (22 and 11 in north and south, respectively) but the coverage of them was 0.2% and 0.1% in north and south, respectively. The 46

47 number of palatable perennial herb was 11 and 7 but the average coverage of them was 0.2% and 0.1% in north and south zone, respectively. The number of palatable perennial grass was 10 and 5 but the average coverage of them was 0.6% and 0.5% in north and south zone, respectively. The number of palatable shrub was 3 and 3 but average coverage of the 4.7% and 1.5% in north and south zone, respectively. The number of unpalatable shrub was 2 and 2 while the average coverage of them 0.5% and 0.0%, unpalatable annual herb was 2 and 1 and the average coverage of them was 0.2% and 0.4% in north and south zone, respectively. The palatable annual species wasn t recorded in south zone. By the two-way analysis of variance for the coverage as shown in Table 13, excepting Caragana microphylla, Achnatherum splendens and Chenopodium acuminathum showing no significant difference, Artemisia frigida, Agropyron cristatum, Cleistogenes squarrosa, Leymus chinensis, Stipa krylvoii, Artemisia adamsii and Carex spp had higher coverage in the north zone than the south zone. On the other hand, only Allium spp showed reverse significant changes in its coverage. 4.3 Annual changes The annual change of average coverage of dominant 12 species was shown in Table 14. In north, the coverage of Caragana microphylla was 4.9, 3.9 and 5.6% while in south zone 3.7, 4.9 and 4.0% in 2009, 2010 and 2011, respectively. The coverage of Artemisia frigida was 5.7, 4.6 and 7.1% in north, 0.1, 0.1 and 0.1% in south in 2009, 2010 and 2011, respectively. The coverage of this species fluctuates in north while it wasn t fluctuating in south zone. In north zone, the coverage of Stipa krylovii was 1.1, 0.8 and 2.3% while it was 0.1, 0.1 and 0.2% in south. The coverage of Agropyron cristatum was 0.8, 0.3 and 1.1% in north, 0.0, 0.0 and 0.1% in south while the coverage of Leymus chinensis was 0.5, 2.1 and 3.6% in north, very low with 0.0% in 3 years in south from 2009 to 2011, respectively. In north, the coverage of Cleistogenes squarrosa was 0.4, 0.6 and 1.0 % while in south it was 0.0, 0.1 and 0.0%, in north, the coverage of Achnatherum splendens was 0.0, 0.0 and 0.1% was and in south 0.0, 0.1 and 0.0%, in north the coverage of Artemisia adamsii was 2.8, 0.9 and 2.8% while in south was 0.1, 0.2 and 0.2% in 2009, 2010 and 2011, respectively. The average coverage of Carex spp was 1.3, 1.4 and 3.2% in north, 0.0, 0.2 and 0.2% in south in 2009, 2010 and 2011, respectively. The Allium Mongolichum was absent in north while the average coverage was 0.3, 1.5 and 6.3% in , respectively. Peganum nigelastrum was absent in north while the average coverage was 0.0, 0.0 and 0.2% in south, the average coverage of Chenopodium acuminathum was 10.6, 8.9 and 21.9% in north, 5.5, 5.8 and 17.4% in 2009, 2010 and 2011, respectively (Table 14). 47

48 4.3.1 Suppressed area In the north zone, 54 species of 29 genera and 18 families, 53 species of 31 genera and 20 families and 56 species of 24 genera and 16 families were recorded in 2009, 2010 and 2011, respectively. Among 54 species which recorded in 2009, 17 (0.1%) unpalatable perennial herbs, 10 (0.4%) palatable grasses, 8 (0.7%) palatable perennial herbs, 6 (3.3%) unpalatable annual herbs, 4 (2.2%) palatable perennial shrubs, 2 (1.6%) unpalatable perennial shrubs, 1 (0.0%) palatable annual herb and 6 (0.1%) species were impossible to determine the palatability. Among 53 species which recorded in 2010, 22 (0.0%) unpalatable perennial herbs, 10 (0.3%) palatable grasses, 8 (0.2%) palatable perennial herbs, 5 (1.6%) unpalatable annual herbs, 3 (2.5%) palatable shrubs, 3 (0.6%) unpalatable shrubs, 1 (0.0%) palatable annual herb and 1 (0.0%) was impossible to determine the palatability. Among 56 species which recorded in 2011, 23 (0.1%) unpalatable perennial herbs, 11 (0.5%) palatable grasses, 8 (0.6%) palatable perennial herbs, 4 (5.5%) unpalatable annual herbs, 3 (3.8%) palatable shrubs, 2 (1.9%) unpalatable perennial shrubs, 1 (0.0%) palatable annual herb and 4 (0.0%) were impossible to determine the palatability (Table 15). In the south zone, 27 species of 19 genera and 11 families, 29 species of 20 genera and 11 families and 33 species of 25 genera and 15 families were recorded in 2009, 2010 and 2011, respectively. Among 27 species which recorded in south zone in 2009, 7 (0.0%) unpalatable perennial herbs, 6 (0.4%) palatable grasses, 4 (0.2%) palatable perennial herbs, 3 (1.2%) unpalatable annual herbs, 3 (0.8%) palatable shrubs, 2 (0.1%) unpalatable perennial shrubs and 2 (0.2%) were impossible to determine the palatability. Ten (0.0%) unpalatable perennial herbs, 5 (0.5%) palatable perennial grasses, 5 (0.2%) palatable perennial herbs, 4 (1.2%) unpalatable annual herbs, 3 (1.3%) palatable shrubs and 2 (0.0%) unpalatable shrubs were recorded in Among 33 species which recorded in 2011, 11 (0.1%) unpalatable perennial herbs, 7 (0.4%) palatable perennial grasses, 6 (0.9%) palatable perennial herbs, 4 (5.6%) unpalatable annual herbs, 3 (1.1%) palatable perennial shrubs and 2 (0.1%) unpalatable shrubs were (Table 14). Table 16 shows the result of one-way analysis of variance for the coverage of each dominant species among the census years in the north and the south zones. In the north zone, all dominant species showed no significant difference of their coverage among census years. While, Chenopodium acuminathum and Allium Mongolichum showed significant difference of their coverage among census years in the south zone, suggesting that their growth had keen relation with the amount of precipitation. 48

49 4.3.2 Endmost area In the north zone, 26 species of 17 genera and 11 families, 33 species of 19 genera and 11 families and 37 species of 22 genera and 12 families were recorded in 2009, 2010 and 2011, respectively (Table 16). Among 26 species which recorded in 2009, 8 (0.3%) palatable grasses, 6 (1.7%) unpalatable perennial herbs, 4 (0.9%) palatable perennial herbs, 3 (7.6%) palatable shrubs, 2 (2.4%) unpalatable shrubs, 2 (1.4) unpalatable annual herbs and 1 (0.0%) palatable annual herb was. There were 11 (0.2%) unpalatable perennial herbs, 7 (1.0%) palatable grasses, 7 (0.2%) palatable perennial herbs, 3 (4.1%) palatable shrubs, 2 (0.3%) unpalatable annual herbs, 1 (0.3%) unpalatable perennial shrub, 1 (0.0%) palatable annual herb and impossible to determine the palatability in Eleven (0.4%) unpalatable perennial herbs, 10 (1.5%) palatable grasses, 8 (0.4%) palatable perennial herbs, 3 (7.1%) palatable shrubs, 3 (0.9%) unpalatable annual herbs, 1 (2.4%) unpalatable perennial shrubs and 1 (0.0%) impossible to determine the palatability were recorded in 2011(Table 17). In the south zone, 15 species of 25 genera and 6 families, 24 species of 18 genera and 9 families and 20 species of 14 genera and 8 families were recorded in 2009, 2010 and 2011, respectively. Three (3.0%) palatable shrubs, 3 (2.8%) unpalatable annual herbs, 3 (0.2%) palatable perennial herbs, 1 (0.3%) unpalatable perennial herbs, 1 (0.2%) palatable grasses and 1 (0.0%) unpalatable shrubs were recorded in Eight (0.1%) unpalatable perennial herbs, 5 (0.2%) palatable perennial 3 shrubs, 5 grasses and 4 herbs were palatable and 10 herbs and 1 annual plat were unpalatable in Six (1.8%) palatable perennial herbs, 5 (0.2%) palatable grasses, 3 (2.5%) palatable shrubs, 3 (0.5%) unpalatable perennial herbs, 2 (6.4%) unpalatable annual herbs and 1 (0.5%) unpalatable perennial shrubs were recorded in 2011(Table 17). Table 18 shows the result of one-way analysis of variance for the average coverage of each dominant species among census years in the north and the south zones. In the north zone, only Stipa krylovii showed significant difference of its coverage among census years. In the south zone, only Allium Mongolichum showed significant difference of its coverage among census years. Both of them were palatable. Other species showed no significant difference of their coverage among these years. 49

50 Table 4. The list of all species which recorded in census years Pala tablity # Family name Genus name Species name N T S N T S N T S 1 Lappula myosotis + + UP herb Boraginaceae Lappula 2 Lappula sp + + Unknown annual 3 Cafrifoliaceae Lonicera Lonicera sp + Unknown herb 4 Arenaria Arenaria capillaris Poir. + + P herb 5 Silene jenescensis Willd. + + UP herb Caryophylaceae Silene 6 Silene repens Patr. + UP herb 7 Stellaria Stellaria dichotoma L UP herb 8 Chenopodium acuminatum Willd UP annual 9 Chenopodium album L. + UP annual Chenopodium 10 Chenopodium aristatatum L. + + UP annual Chenopodiaceae 11 Chenopodium sp + UP annual 12 Kochia Kochia prostrata (L.) Schrad P herb 13 Salsola Salsola collina Pall UP annual 14 Artemisia adamsii Bess UP shrub 15 Artemisia dracunculus L UP herb 16 Artemisia frigida Willd P shrub Compositae Artemisia 17 Artemisia macrocephala Jacquem UP annual 18 Artemisia mongolica Fisch. Ex Nakai + UP shrub 19 Artemisia palustris L. + UP annual 2009 Life form 50

51 Table 4 (continue). The list of all species which recorded in census years Pala tablity # Family name Genus name Species name N T S N T S N T S 20 Artemisia pectinata Pall. + UP annual 21 Compositae Artemisia Artemisia scoparia Waldst. Et Kit UP shrub 22 Artemisia sp + Unknown herb 23 Heteropapus Heteropappus hispidus (Thunbg.) Less UP herb 24 Leauzea Leauzea uniflora (L.) Holub + + UP herb 25 Rhaponticum Rhaponticum uniflora (L.) DC P herb 26 Saussurea Saussurea salicifolia (L.) UP herb 27 Serratula Serratula centauroides L. + UP herb 28 Taraxacum Taraxcum sp + Unknown herb 29 Convolvulaceae Convolvulus Convolvulus ammanii Desr UP herb 30 Dontostemon Dontostemon integrifolius (L.) C.A.Mey P annual Cruciferae 31 Ptilotrichum Ptilotrichum canescens C. A. Mey UP herb 32 Carex korshinskyi Kom P herb Cyperaceae Carex 33 Carex pediformis C.A. Mey P herb 34 Ephedraceae Ephedra Ephedra sp UP herb 35 Gentiana Gentiana sp + Unknown herb Gentianaceae 36 Erodium Erodium stephanianum Willd UP annual 37 Achnatherum Achnatherum splendens (Trin) Nevski P grass Graminae 38 Cleistogenes Cleistogenes sp + + P grass 2009 Life form 51

52 Table 4 (continue). The list of all species which recorded in census years Pala tablity # Family name Genus name Species name N T S N T S N T S 39 Cleistogenes Cleistogenes squarrosa (Trin.) Keng P grass 40 Festuca Festuca sp + P grass 41 Koeleria Koeleria macrantha (Ldb.) Schult P grass 42 Leymus Leymus chinensis (Trin.) Tzvel P grass 43 Poa sp P grass 44 Poa attenuata Trin. P grass Graminae Poa 45 Poa botryiodes Trin P grass 46 Poaceae sp + Unknown grass 47 Stipa baicalensis Roshev P grass 48 Stipa Stipa krylovii Roshev P grass 49 Stipa sibirica (L.) Lam P grass 50 Trisetum Trisetum sp + Unknown grass 51 Iris sp Unknown herb Iridaceae Iris 52 Iris tigridia Bge. + UP herb 53 Dracocephalum Dracocephalum foetidum Bge. + UP herb 54 Leonurus Leonurus deminutus Krecz. + UP herb Labiatae 55 Lophanthus Lophanthus chinensis (Raf.) Benth. + UP herb 56 Scutlera Scutlera sp + Unknown herb 57 Leguminosae Astragalus Astragalus sp + + Unknown herb Life form 52

53 Table 4 (continue). The list of all species which recorded in census years Pala tablity # Family name Genus name Species name N T S N T S N T S 58 Caragana leucophylla Pojark. + P shrub 59 Caragana Caragana microphylla (Pall.) Lam P shrub 60 Caragana stenophylla Pojark P shrub 61 Leguminosae Medicago Medicago ruthenica (L.) Ldb P herb 62 Oxytropis Oxytropis sp UP herb 63 Thermopsis Thermopsis dahurica R.Br UP herb 64 Trifolium Trifolium lupinaster L. + + UP herb 65 Allium bidentatum Fisch P herb 66 Allium Mongolicum Roshev P herb 67 Liliaceae Allium Allium odorum L P herb 68 Allium polyrhizum Turcz. ex Ldb. + P herb 69 Allium sp P herb 70 Papaveraceae Chiazospermum Chiazospermum erectum L. + UP annual 71 Plumbaginaceae Goniolimon Goniolimon speciosum (L.) Boisss UP herb 72 Poaceae Agropyron Agropyron cristatum (L.) P. B P grass 73 Polygonum Polygonum angustifolium Pall P herb Polygonaceae 74 Rheum Rheum undulatum L UP herb 75 Leptopyrum Leptopyrum fumarioides (L.) Reichb UP annual Ranunculaceae 76 Thalictrum Thalictrum foetidum L. + + UP herb 2009 Life form 53

54 Table 4 (continue). The list of all species which recorded in census years Pala tablity # Family name Genus name Species name N T S N T S N T S 77 Thalictrum petaloideum L UP herb 78 Ranunculaceae Thalictrum Thalictrum simplex L. + UP herb 79 Thalictrum sp + UP herb 80 Chamaerhodos Chamaerhodos erecta (L.) Bge UP annual 81 Potentilla acaulis L UP herb 82 Potentilla bifurca L UP herb 83 Rosaceae Potentilla Potentilla conferta Bge P herb 84 Potentilla muiltifida L P herb 85 Potentilla viscosa G. Don UP herb 86 Sibbaldianthe Sibbaldianthe adpressa (Bge.) Juz UP herb 87 Rutaceae Haplophyllum Haplophyllum dahuricum (L.) G. Don UP shrub 88 Cymbaria Cymbaria dahurica L UP herb 89 Pedicularis Pedicularis sp + Unknown herb Scrophulariaceae 90 Thymus Thymus gobicus Tschern UP shrub 91 Veronica Veronica incana L. + UP herb 92 Umbelliferae Bupleurum Bupleurum bicaule Helm. + P herb 93 Urtica cannabiana L. + + UP herb Urticaceae Urtica 94 Urtica sp + + UP herb 95 Zygophyllaceae Peganum Peganum nigelastrum Bunge. + + UP herb Life form 54

55 55

56 56

57 Table 6 List of totally species which recorded in study site. Life form Shrub Grass Annuality Perennial Annual Perennial Annual Palatablity P UP P UP P UP P UP Coverage N T S N T S N T S N T S N T S Artemisia frigida Willd Artemisia adamsii Bess Achnatherum splendens Caragana leucophylla Artemisia mongolica Agropyron cristatum Caragana microphylla Artemisia scoparia Cleistogenes sp Caragana stenophylla Haplophyllum davuricum Cleistogenes squarrosa Thymus gobicus Festuca sp Koeleria macrantha Leymus chinensis Poa sp Poa attenuata Poa botryiodes Trin Stipa baicalensis Roshev Stipa krylovii Roshev Stipa sibirica (L.) Lam

58 Table 6 (continue) List of totally species which recorded in study site. Life form Herb Annuality Perennial Annual Palatablity P UP P UP Coverage N T S N T S N T S N T S Allium bidentatum Artemisia dracunculus Dontostemon integrifolius Artemisia macrocephala Allium Mongolicum Chamaerhodos erecta Artemisia palustris L Allium odorum L Convolvulus ammanii Artemisia pectinata Allium polyrhizum Cymbaria dahurica L Chenopodium acuminatum Allium sp Dracocephalum foetidum Chenopodium album L Arenaria capillaris Ephedra sp Chenopodium aristatatum Bupleurum bicaule Goniolimon speciosum Chenopodium sp Carex korshinskyi Heteropappus hispidus Chiazospermum erectum Carex pediformis Iris tigridia Bge Erodium stephanianum Kochia prostrata Lappula myosotis Leptopyrum fumarioides Medicago ruthenica Leauzea uniflora Salsola collina Pall Polygonum angustifolium Leonurus deminutus Potentilla conferta Bge Lophanthus chinensis Potentilla muiltifida L Oxytropis sp Rhaponticum uniflora Peganum nigelastrum Potentilla acaulis L Potentilla bifurca L Potentilla viscosa Ptilotrichum canescens Rheum undulatum L Saussurea salicifolia Serratula centauroides L Sibbaldianthe adpressa Silene jenescensis Silene repens Stellaria dichotoma L Thalictrum foetidum Thalictrum petaloideum Thalictrum simplex Thalictrum sp Thermopsis dahurica Trifolium lupinaster Urtica cannabiana L Urtica sp Veronica incana

59 59

60 60

61 61

62 62

63 63

64 64

65 65

66 66

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69 CHAPTER 5: GRAZING PRESSURE 1. Grazing gradient from winter camp From the center of winter camp, grazing pressure seemed to be gradually decreased with the distance because of the grazing area increased by the square of distance from the center. Then the distance from the center was the suitable indicator for the grazing pressure. In order to analyze the effect of grazing pressure, vegetation changes from the center of winter camp were analyzed for each dominant species as shown in Figure 18. In both zones, the coverage of Caragana microphylla increased from winter camp with grazing gradient in each year (Figure ). The Artemisia frigida was increased from winter camp with grazing distance in both zones (Figure ). The Stipa krylovii, Agropyron cristatum were increased in north and south from winter camp with grazing distance (Figure ). The average coverage of Leymus chinensis was increased in north while in south was rare (Figure ). Achnatherum splendens was very rare in north while decreased from winter camp with grazing distance, especially in 2010 and 2011 (Figure ). But, the coverage of it was very low in endmost area in each year. Artemisia adamsii and Carex spp weren t show any trend with grazing distance in north and south (Figure ). Allium Mongolichum was absent in north but wasn t show trend with grazing gradient in 2009 while increased from winter camp with grazing distance in south in 2010 and Chenopodium acuminathum was clearly decreased from winter camp with grazing distance in north zone but in south zone wasn t show clear trend in 2009 and 2010 while drastically decreased from winter camp to grazing distance in 2011 (Figure ). The average coverage of Cleistogenes squarrosa increased from winter camp with the grazing distance in north in 2010 and 2011 but it was very rare in south in census years (Figure 21-22). Peganum nigelastrum was absent in north while in south decreased from winter camp with grazing gradient especially in 2011 (Figure ). As these figure, the trend of the most dominant species with grazing gradient was monotonously in each census year. 2. Types of spatial change in vegetation coverage According to the spatial changes in vegetation coverage for all species, four typical types of changes were detected, which could denoted as negative, positive, independent and temporal relations as shown in Figure

70 2.1 Negative relationship The vegetation coverage decreases monotonously from the center of winter camp to the end of observed area, 1600m from the camp. The vegetation coverage had negative relationship with the distance from the center. The increase of vegetation coverage with the increase of grazing pressure indicated high grazing tolerance such as unpalatable or great preference of disturbed habitat condition like pioneer species. For example, Chenopodium acuminathum shown in Figure 20-1 could cover about 80% of the ground just near the winter camp and drastically decreased to 800m. It could dominate only 0.9% of the ground at 1600m site which seemed under almost the natural condition without or only a little grazing pressure. 2.2 Positive relationship On the other hand, the vegetation coverage at the center of winter camp showed the lowest value, almost zero, and increased toward as the distance become long toward the end of observed site, which was denoted as positive relationship. Grazing pressure had a great effect on their growth, because of high palatable or intolerance of habitat disturbance. The typical palatable grass species, Stipa krylovii shown in Figure 20-2 was absent around the winter camp and monotonously increased its coverage with 11.6% at 1600m. 2.3 Independent relationship The vegetation coverage could maintain a certain stable level at all location from the winter camp indicating independent relationship with grazing pressure. Although Artemisia adamsii was absent at the center of winter camp, the coverage became 12.4% at 50m from the center and maintained the same level of coverage around 10% toward the end of observed site. Such relationship indicates that not only little effect of grazing pressure and habitat disturbance on plant 70

71 growth, but also little promotion by the decrease of competition within plant community (Figure 20-3). 2.4 Temporal relationship The vegetation coverage showed some convex changes with the distance from the center as shown in Figure 18, denoted as temporal relationship. In comparison with species of independent relationship, this relationship was cause by both grazing pressure and other factor(s) including competition within plant community. The vegetation coverage of Heteropapus hispidus as shown in Figure 20-4 was 1.3% at the center and increased to 23.2% at 800m from the center. However, it drastically decreased to 1.1% at 1600m. 3. Species of each relationship 3.1 Dominant species Dominant species shown in Table 19 did not show the same relationship. Caragana microphylla, Artemisia frigida, Stipa krylovii, Agropyron cristatum, Allium Mongolichum and Cleistogenes squarrosa, which dominated both in the north and the south zones showed positive relationships as shown in Figure , , , , and , respectively. However, Artemisia adamsii and Carex spp dominating both in the north and the south zones did not show any trend of change of their coverage with the distance from the camp (Figure , , respectively). 71

72 3.2 Negative relationship Achnatherum splendens, Peganum nigelastrum and Chenopodium acuminathum dominating north and south showed negative relationship as shown in Figure , and , respectively. 3.3 Positive relationship Caragana microphylla, Artemisia frigida, Stipa krylovii, Agropyron cristatum, Allium Mongolichum and Cleistogenes squarrosa, which dominated both in the north and the south zones showed positive relationships as shown in Figure , , , , and , respectively. 3.4 Independent relationship However, Artemisia adamsii and Carex spp dominating both in the north and the south zones did not show any trend of change of their coverage with the distance from the camp. These species showed independent relationship with grazing distance in Figure , , respectively. 3.5 Temporal relationship This trend wasn t occurred in dominant species but other species such as Heteropapus hispidus, Potentilla acaulis and Arenaria capillaris showed temporal relationship as shown in Figure

73 4. PFT of each relationship As mentioned before, vegetation coverage would have great relation with the PFT. The relation types of each PFT were shown in Table 20. Two species of the total 84 species included in PFT could not determine the relation type. 4.1 Negative relationship All (7) unpalatable annual species and 1 unpalatable perennial species were negative relationship as shown in Table 20 indicating high sensitivity to habitat degradation by grazing pressure. These species are including 13.1% and 1.2%, respectively of the total percent of coverage. The dominant species of this group were unpalatable annuals, Chenopodium acuminathum and Salsola collina in the north and the south zones and Artemisia scoparia in the north zone. 4.2 Positive relationship In positive relation type, all (13) grass species, 5 palatable herbs and all (4) palatable shrubs were included and the percent of coverage were 15.5, 6 and 4.8%, respectively. The representative species are Caragana microphylla, Stipa krylovii and Allium Mongolichum. 4.3 Independent relationship In this type, most palatable and unpalatable herb species were included and shown 51.2% of all species coverage. The representative species were Artemisia adamsii, Carex spp, Artemisia scoparia, Convolvulus ammanii and Chenopodium acuminathum. 4.4 Temporal relationship The small number of unpalatable perennial herbs was included in this type such as Heteropapus hispidus, Potentilla acaulis and Potentilla bifurca. 73

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84 CHAPTER 6: THE KEY INFORMANT`s EVALUATIONS 1. Species characteristics of several important plants In the steppe of Mongolia, Caragana microphylla, Stipa krylovi,i, Cleistogenes squarrosa, Agropyron cristatum, Leymus chinensis, Carex spp and Artemisia frigida were main dominants (Yunatov, 1976; Hilbig, 1995; Chognii, 2001). 1.1 Dominant shrubs Shrubs (Caragana microphylla, Artemisia frigida and Artemisia adamsii) can sprout even in dry spring because of their deep root system (Yamada et al, 2009; Fujita, 2012). Caragana microphylla and Artemisia frigida are drought tolerant Caragana microphylla as a nurse plant In arid and semiarid areas, large sized plants may have a positive effect on the growth and survive of small plants growing under their canopy or branches (Raffaele and Veblen, 1998). For example, Caragana microphylla generally reduce the intensity of wind erosion and can promote growth of small plants (Sanchir, 1974; Su et al, 2004). Such nurse effect of Caragana microphylla (Raffaele and Veblen, 1998) as a benefactor species may affect species composition and increases resilience of plant community far from the camp. Moreover, Caragana microphylla gathers sand around its base and makes a small mound beneath the canopy which has some benefits for other small plants. On the other hand, as the high palatability of Caragana microphylla, most of their foliage is eaten under heavy grazing and it becomes small and dwarf shape. As a result, this species seldom act as a nurse plant under natural condition of Mongolian rangeland with generally heavy grazing intensities. In the steppe and dry steppe (between Ulaanbaatar and Mandalgobi), Caragana microphylla can dominates widely with high density (Sasaki, 2008; Fujita, 2012). C. microphylla is C 3 plant, but it can grow in dry condition. Moreover, Caragana is Fabaceae which can fix nitrogen. Therefore, Caragana`s leaves and flowers contain high amount of protein and fiber which means that this species is good for livestock (Jigjidsuren and Johnson, 2003). In a dry spring with little precipitation, herbs cannot grow but Caragana microphylla can produce leaves (Yamada et al, 2009). Moreover, Caragana microphylla can maintain its leaves even under long drought, in which herbs suffer serious damage on their growth. Therefore, Caragana 84

85 microphylla grow in wide range of climate condition. In this result, the coverage of Caragana microphylla in the north and the south zones was 4.7 and 4.1% respectively, which as not significantly different (p=0.75) (Table 8) Artemisia frigida Artemisia frigida is the one of the most important species of this study site because of its good nutrient for livestock. Therefore this species is very important as fodder in spring. The nutrition of bloomed Artemisia frigida become in maximum scale in early spring then it can be first good fodder in harsh dry spring and protein of this species become 16.2% in such period (Tserendash and Bolormaa, 2006) Artemisia adamsii Xerophytic semi shrub. Roots thin rhizomatous. With essential oil plant. Not important for forage. Recognized as an indicator of pasture degradation (Jambal and Oyuntsetseg, 2008). 1.2 Dominant grasses Stipa krylovii Stipa is the most important genus in grasslands of the cool temperate semi-arid zones (Nakamura et al, 1988). Stipa krylovii (Graminae) is one of the major grassland species in the moderate temperate zone of Central Asia (Li Xin, 2012). It is perennial tussock grass with rich nutrients and palatable. It can tolerate for grazing and trampling. However, less drought-resistant resulting gradual recede when faced with increasing dryness. Moreover, it is incapable of successive competition with drought resistant species in the south zone. Stipa krylovii can produce much seeds, but under the relatively dry conditions, seedlings are not commonly found and do not establish well. Stipa is a caespitose grass with a much slower lateral spread. It does not make long rhizomes but it relatively slowly increases its bunch size by growing more tillers. Stipa bunches can break up as part of the bunch die off (Staalduinen, 2005). In recently, the original dominant Stipa grasses were replaced by other grasses like Leymus chinensis, Cleistogenes squarrosa and ruderal plants species (Hilbig, 1995). 85

86 1.2.2 Leymus chinensis Leymus chinensis is a perennial grasses growing under the relatively dry conditions. It shows a fast lateral spread by forming rhizomes (Staalduinen, 2005). Under light or moderate grazing Stipa krylovii is the dominant species, but under a higher grazing intensity Stipa krylovii decreases and the rhizomatous Leymus chinensis and Carex duriusculla become dominant (Hilbig, 1995; Fernandez-Gimenez and Allen Diaz, 2001). This phenomenon where the original dominating caespitose species are being replaced by rhizomatous species when grazing pressure by livestock increases is common in many other semi arid grassland areas, e.g. Inner Mongolia, Northern China and North American steppe (Mack and Thompson, 1982; Milchunes et al, 1988) Cleistogenes squarrosa Cleistogenes squarrosa is a C4 tussock grass and has many buds and can regrow one ot two times per year. Therefore, Sanjid (2002) hypothesized that Cleistogenes squarrosa would increase through warming. Moreover, Chognii (2011) have shown that Cleistogenes squarrosa is increased through light and moderate grazing, as well as after a steppe fire (Tuvshintogtoh, 2007). Those results are ratified by our study Agropyron cristatum With the important role species on pasture of livestock and xerophytic perennial bunch grass. Palatable to all livestock throughout year. Nutrient value is high. Protein content is % and fiber is % when blooming. Metabolic energy per kg of hay is 8.6Mj and protein is 56-70g. Stems stand upright in winter and spring making it important for forage. Annual yield is relatively stable (Jigjidsuren and Johnson, 2003) Achnatherum splendens This species is a bushy grass and can form large and dense community in dry area. Achnatherum splendens is highly drought tolerant because this species can grow in relatively humid and stable condition (lower land with shallow groundwater) which is free from water shortage. The vegetation cover of this species can be remained even under drought (Sasaki et al, 2009). Pastoralists, therefore, tend to use Achnatherum community in drought (Grubov, 1982). After the decay of aboveground of both herbs and deciduous shrubs in wither, the withered aboveground biomass of Achnatherum splendens was still available for fodder until the next spring. But its importance for fodder is limited for only in winter because of its bad taste. As it does not occur around winter camp 86

87 in the north zone, pastoralists don t use this species as a safety net in dzud in the north zone. Old culms of Achnatherum splendens become hard to protect soft new shoots. 1.3 Dominant herbs Carex spp High percentage of vegetation coverage of Carex duriusculla around wet site indicated the result of intensive grazing (Hilbig, 1995). Carex duriusculla contains perennial rhizomatous sedges with triangular. This is palatable to horses and cattle until autumn and poor palatability to small livestock. Nutrient value is not well studied. Carex duriusculla increased in due to grazing, as these species were regarded as good indicators of over grazed stands (Ichiroku, 2006) Allium spp Allium spp (Allium polyrhizum and Allium Mongolichum) grow in dry steppe and desert steppe while rare in the north. Allium polyrhizum is with fibrous root. Height is cm. This species has much protein and tolerant for trampling. Most of above ground is dead in the autumn and it begins to dormant until in the next spring, during which this species is not suitable for fodder. In spring, rain promotes its quick growth. This species can regenerate both from seeds and vegetative shoots. Allium Mongolichum is perennial and palatable herb and can distribute only in dry steppe (Jigjidsuren and Johnson, 2005). Allium Mongolichum is sensitive for humidity changes, shows direct relation with precipitation in its growth. They can quickly grow after rain (Tuvshintogtoh, 2007). According Fujita (2012), this species was dominant under canopy of Caragana microphylla and Caragana stenophylla. However, Allium Mongolichum could grow in dry area without any Caragana vegetation under rainfall, which means the protection by Caragana canopy is not the necessity of it s establish. In this research, Allium Mongolichum could distribute wide area without Caragana. In the south zone, vegetation coverage of Allium Mongolichum was significantly higher in 2011 than 2009 and 2010 showing a keen relation with amount of precipitation. After heavy rain in 2011 in the south zone, its pink flowers covered the most rangeland. 87

88 1.3.3 Chenopodium acuminathum Chenopodium acuminathum was dominated in both of the north and south zones. It is annual herb and weedy species that increases in abundance by grazing on Mongolian rangeland (Fernandez-Gimenez and Allen Diaz, 2001). Chenopodium acuminathum is unpalatable annual herb resulting high coverage under high grazing pressure near the centre of winter camps (25-50m). 2. Geographical variation According to the vegetation structure, the study area was divided into two parts from north to south, namely the north zone and the south zone. 2.1 The north and south zone Vegetation coverage is generally higher in the north zone than the south zone along 450km distance. The number of grass and herbs showed a gradual decrease from north to south with changes of humidity, however shrubs maintained stable level of species number suggesting their drought tolerance. In the north zone, a remarkable annual change in vegetation coverage was detected such as Stipa krylovii (in endmost area), because of the relatively stable condition in annual variation. But, in the south zone, Allium mongolicum (endmost and suppressed area) and Chenopodium acuminathum (in suppressed area) showed remarkable annual changes around a winter camp, for example a significantly greater increase in coverage were observed in 2011 than 2009 and These changes seemed to have keen relation with precipitation. In such wet year, most livestock can feed on this species (Allium mongolicum) in summer in the south zone, although Chenopodium acuminathum is never be used for fodder in the north zone because of the selection of fodder is higher in north area. Livestock in the south zone had to depend on Caragana microphylla during natural disaster in 2009 and As these main species of Allium mongolicum and Chenopodium acuminathum in the south zone prefer to grow in disturbed condition, there is a great possibility to invade other species to overcome these species after long period of good weather condition being suitable for vegetation recovery. For the inhabitation of pastoralists, such calm and stable condition is necessary to last for a certain long years. However, from the view point of equilibrium and non-equilibrium theory, weather condition in the south zone is not stable in comparison with that in the north zone to recover the natural vegetation condition without environmental variation. Allium spp and Chenopodium acuminathum showed drastic fluctuates in their coverage because of their sensitivity 88

89 to changes in humidity. According to the prediction that non-equilibrium dynamics predominate in areas where mean annual precipitation is less than 250 mm and precipitation coefficient of variation exceeds 33% (Kakinuma, 2013). As the comparison of amount of precipitation, in north between Darkhan (Station1), Hustai (Station2) and Zuunmod (Station3), the total precipitation were 344, and mm, respectively and it is considering to be in equilibrium condition. Although, total precipitation were 187.5, and 99.1mm in BayanOnjuul (Station4), Adaatsag (Station5) and Mandalgobi (Station6), respectively and it is considering the non-equilibrium condition. According to the non-equilibrium model, management based on constant and conservative stocking rates is inappropriate and costly to pastoralism in such variable systems, as carrying capacities vary with precipitation (Behnke, 1993), rainfall is a primary driver of vegetation dynamics (Dorji, 2010; Wesche et al., 2010; Cheng et al., 2011). 2.2 Transit zone Between the north and the south zones, transitional zone is detected, in where classification of vegetation structure was varied year by year in accordance with yearly changes in weather condition. The width of the transitional zone was estimated about 90km. The transitional zone is better to study to clarify the way of management by pastoralists affecting grazing gradient and vegetation conditions. From the interview, herders in the south zone are apt to move and track in this transitional area to find fresh pastures. Especially in harsh period, such as drought in summer and dzud in winter, pastoralists from the south zone are easy to invade in this fertile rangeland resulting heavy grazing pressure. Moreover, the high accessibility of this are being next of the capital promotes high concentration of livestock. The species composition of study sites is decreasing from north to south it means that the plant distribution also was related with climate gradient. The reason in movement of transitional zone in each year could not be clarified from this study. But, from interview data, the owners inhabiting in the transitional zone from the south zone did not want to stay in this zone for long period but to use it only during harsh winter. The number of livestock staying in such manner is not clear. 89

90 3. The mortality of livestock during dzud The total number of pastoralists which included north group was 312 and 218 while in south was 528 and 278 in 2009 and 2010, respectively. As this number, the number of livestock decreased and the mortality percent was 30.0 and 47.4% in north and south zones, respectively (Figure 21). The mortality of each kind of livestock was shown in Figure 22. As figure, goat and cow were affected by dzud. The mortality of goat was 30.6 and 59.2% while of cow 36.8 and 51.0% in north and south, respectively. As the valuable cashmere, recently the number of goats doubled during 1990`s because of great demand of cashmere (National Statistical Office of Mongolia, 2003). But goat and cow were most vulnerable to natural disaster. It shows that the ability to resistant the natural disaster of these kinds of livestock is not good. 90

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92 DISCUSSION 1. Why were winter camps selected for study sites? Mongolian pastoralists have been using the winter camp for long period between November-May to protect their livestock from harsh weather in winter. Most pastoralists construct livestock pen at the center of their winter camp sites, which were located at the foot of mountain, on the south facing slope to avoid strong cold wind from north. Livestock kept in a pen at night and start to feed on dried grass growing in front of the winter camp. However, it is necessary to move for long distance from the camp to get enough amounts of dried fodder as the settlement period progress in winter. The longer the distance from the winter camp, the lower the grazing pressure becomes. Then grazing pressure gradually decreases from the center of winter camp to the outer part of winter camp site. Plant species having high tolerance against livestock grazing can dominate over the area with severe disturbance, such as the neighbourhood area around the winter camp. As a result, the distance from winter camp can be considered as an indicator of the grazing intensity to analyze the effect of pastoralism on vegetation structure in rangeland. Changes in coverage of PFT including life forms and growth forms along grazing gradient were studied by the analysis of the effect of livestock activity on rangeland vegetation structure (Hoshino et al, 2009). The topographical condition of winter camps in north and south zone is different. Winter camps were established on a gentle slope of hillside in north while winter camps which located were in lowland of large plain in south zone (Figure 23). It related with harsh climate condition. In order to protect their livestock from harsh weather in winter, pastoralists construct livestock camps, which were often located at the foot of a mountain, facing south, to avoid strong wind in north area while locating in lowland warm place in south zone. 2. The pastoralists` strategy Pastoralists choose the grazing strategies by balance of cost and benefit of mobility and thus grazing strategies were different by pastoralists` economic situation (Baker and Hoffman, 2006). 92

93 For example, wealthy pastoralists tend to be frequently moving in order to explorer the good resource and poor pastoralists are not in order to reduce the cost of mobility in high variable condition (Baker and Hoffman, 2006). In this study, pastoralists in south zone were frequently moved in drought and in period of not sufficient of pasture while pastoralists don t move in north. Pastoralists which live in north zone don t move comparing with pastoralists in south zone, it may relate with the vegetation condition based on equilibrium environment. Kakinuma (2013) concluded that if pastoralists have good economic condition they can escape from natural disaster and if they exploit the rainfall variation, they should move long distance and high frequency. On the other hand, if pastoralists don t have good economic condition they cannot move long, high frequent moving and cannot escape from natural disaster. This situation was observed also in this case but interesting was observed. For example, 2 pastoralists who with similar livestock number (more than thousand) live in winter camp with number 15 and 19 in south zone. The number of livestock of these 2 pastoralists` is not so different and most wealthy families in selected pastoralists but the mortality of livestock was very different. Owner of winter camp 15 was fenced the Achnatherum community (Figure 24) and use this fenced community during dzud. As this strategy the mortality of livestock of this pastoralist was very few compared with livestock mortality of pastoralist in winter camp 19 who don t use such kind fenced community (Table 21). It was good strategy especially in harsh winter and spring. Local pastoralists used the different resources between normal summers and droughts and during the normal summers the pastoralists used all types communities while using mostly Achnatherum community in drought (Kakinuma, 2013). 3. Species composition The pattern of floristic composition was determined by grazing intensity together with palatability, which was the dominant environmental effect (Sasaki, 2004, Li, 1989, Nemoto et al, 1994, 1997; Wang and Ripley, 1997; Nakamura et al, 1998, 2000; Wuyunna et al., 1999; Yuruhan et al., 2001). Tserendash (2006) reported about 120 species from Mongolia steppe and 3-5 of them could be considered as an important species to maintain rangeland. In this study, about the same number of species (95 species) was recorded and 3 or 5 species, such as Caragana microphylla, Artemisia frigida and Stipa krylovii in north zone and Caragana microphylla, Achnatherum splendens and Allium spp were in south zone seemed to be important for rangeland ecosystem as mentioned later. As comparison the total number both study, the species which occurred in this research site could be represent the general condition of steppe of Mongolia. From the view point of quantitative 93

94 aspect of grassland production, herbs and shrubs are important, especially the herbs are important for the species diversity while shrub and grass can be produce big massive in rangeland ecosystem. Each plant species has an original range of distribution along environmental gradients and behaves independently in response to the environment. 4. PFT 4.1 Life form Shrubs 9 species shrubs were recorded and the average coverage of them was 3.0% in all study sites during 3 census years. Generally, genus of Caragana species dominant in this study area, such as Caragana microphylla, C. stenophylla, C.leucophylla and C. pygmea (Hilbig, 1995; Chognii, 2001). Caragana microphylla is becoming most important species in this study area, especially in south zone this species become the key resource for livestock during yearlong and it confirmed by interview of local pastoralists Grasses The average coverage was 1.9% of total 15 species grass which recorded in this study area. In the north zone, dominant grasses were Stipa krylovii, Agropyron cristatum, Poa spp and Leymus chinensis, as same as results of Staalduinen (2005), Chognii (2001) and Fujita (2012). On the other hand, in the south zone, dominant grasses were changed to Achnatherum splendens, Cleistogenes squarrosa and Agropyron cristatum. Sasaki (2009) and Kakinuma (2013) had reported about the same species domination. Most of these dominant species could grow in both zones such as Caragana microphylla, Stipa krylovii and Agropyron cristatum. While palatable some species such as, Stipa krylovii and Leymus chinensis in north area, Achnatherum splendens in south area were mostly distributed. But the coverage of these palatable grass species significantly decreased from north to south it will describe in next parts. 94

95 4.1.3 Herbs Tserendash (1995) concluded that the most of species are herbs in steppe of Mongolia. In this study more than 70 species were herbs and with comparing total species composition it is big scale but the average coverage of such herbs was 3.1%. It shows that the coverage of herb species is not so much in Caragana steppe. As species diversity of herbs is much then it has big role in ecosystem of this steppe. In the north zone, Carex spp and Chenopodium acuminathum dominated while, in the south zone, Allium Mongolichum, Chenopodium acuminathum, and Peganum nigelastrum dominated. In both zones, the number of herbs was high because all of this experimental area belongs to Caragana steppe having many kinds of herbs. From palatable herb species such as, Carex spp, Kochia prostrata were dominated in north zone while only Allium Mongolichum was dominated in south zone. 5.Palatability Shrubs Caragana microphylla and Artemisia frigida were palatable shrubs Grasses All grass occurred in this experimental site was palatable. Especially Agropyron cristatum, Stipa krylobii, Achnatherum splendens and Poa spp were good fodder in both quality and quantity. Local nomadic people call these plants nariin nogoo or nariin ovs in Mongolian which means fine plants (Nachinshonkhor, personal communication). By the interview, many pastoralists indicated the decrease of palatable species, such as Stipa krylovii, Koeleria macrantha, Poa spp, Agropyron cristatum and Festuca spp even in healthy grassland by the continuous climate changes. These fine species with very high nutrient content (Dashzeveg, 1983 and Tserendash, 1993) can be good forage and necessary for physical condition of livestock. During drought, the leaves of xerophytes dominant species such as Leymus chinensis, Stipa krylovii, and Achnatherum splendens can roll up along vertical axes to get narrow to overcome water deficit. Pastoralists usually used to herd in rangeland with many small and highly palatable graminoids such as Poa spp, Agropyron cristatum, Koeleria macrantha and Cleistogenes squarrosa (Jigjidsuren and Johnson, 2003) but during drought there were few small graminoids (Sasaki et al, 2009). 95

96 5.1.3 Herbs Throughout increasing grazing pressure, mesophytes and unpalatable species increased more than 50%, and xerophytes decreased in Ovor Baigal and Inner Mongolia (Chognii, 2011). Annual C4 plants such as Salsola collina and Chenopodium acuminathum can increase their coverage after cessation of grazing. However, Chenopodium acuminathum is an unpalatable species (Tuvshintogtoh, 2001). 6.Grazing effect in regional scale 6.1 Species composition and dominant species in north and south zone As our result, grazing affected the structure of vegetation is differently in north and south. That is, the species composition in both zones responded differently to grazing. The number of species composition different between study sites which located in north and south. It was higher in north (82 species) than south (49 species) zones in three years. The main change between both zones was the dominant species. Only, Caragana microphylla and Chenopodium acuminathum are dominated in both areas, but other dominant species dissimilarity in these areas, such as in north, the indicator species of typical steppe Artemisia frigida, Stipa krylovii and Leymus chinensis (Staalduinen (2005), Chognii (2001) and Fujita (2012), Artemisia adamsii and Carex spp were dominated while were only Allium Mongolichum and Achnatherum splendens in south zone. 6.2 Dominant species changes from north to south zone All grass species which recorded in our study were perennial palatable grass and most annual species were unpalatable. The proportion of palatable and unpalatable of shrubs was similar. The most perennial herbs were unpalatable. Palatable shrub species One of the dominant palatable shrub species Caragana microphylla was stable distributed in both zones because of our study sites were selected in Caragana steppe. The average coverage of this species wasn t different (p=0.388) from north (4.7%) to south (4.1%) while another palatable shrub Artemisia frigida (maximum height 16 cm) significantly decreased (p=0.001) from north (5.5%) to south (0.0%) in Table 8 and

97 Unpalatable shrub species The unpalatable shrub Artemisia adamsii (maximum height 21 cm) decreased (p=0.017) from north (2.2%) to south (0.1%) in Table 8 and 12. Palatable perennial grass species The palatable dominant species Stipa krylovii significantly decreased (p=0.010) from north (1.1%) to south (0.2%) and another grasses Leymus chinensis (p=0.000), Agropyron cristatum (p=0.005) and Cleistogenes squarrosa (p=0.003) are significantly decreased from north (2, 1.1, 0.7 and 0.5%, respectively) to south (0.0% all of them) it means that became very rare like absent in south (Table 8 and 12). But, Achnatherum splendens very rare in study sites of north zone and dominated in south zone (average coverage 1.9%). It related the different selection of location of winter camps in north and south zones. In north, the location of winter camp usually in far from Achnatherum community while in south located in inside of such community. Recently the pastoralists who stay in south zone usually are fencing the Achnatherum community to keep fodder livestock during hard period (Figure 24). Palatable perennial herb species Allium Mongolichum was absent in north while greatly dominated (2.4%) with high rank in south zone (Table 8). Unpalatable perennial herb species Peganum nigelastrum was absent in north while dominated (0.2%) in south zone (Table 8). Unpalatable annual herb species Chenopodium acuminathum is an annual herb and weedy species that increases in abundance with grazing on Mongolian rangelands (Fernandez-Gimenez and allen Diaz, 2001). The average coverage of Ch. acuminathum was highest 13.9 and 9.7% in north and south zones with significantly decreased (p=0.027), respectively (Table 8 and 12). The abundance of dominant grass species such as, Stipa krylovii (xerophytic, palatable), Agropyron cristatum (xerophytic palatable), Leymus chinensis (xerophytic palatable) and Cleistogenes squarrosa (xerophytic palatable) are decreased from north to south it may more affected by grazing intensity with related the lower species diversity in south area. The number of most PFT, except palatable and unpalatable shrub species drastically decreased from north to south. Especially, the herb annual unpalatable species was drastically decreased from north to south it may be related the precipitation because of annuals directly depends from amount of precipitation. 97

98 7. Temporal changes in grazing effect In north, the average coverage of perennial shrub Caragana microphylla was 4.9, 3.9 and 5.6% while in south, 3.7, 4.9 and 4.0% in 2009, 2010 and 2011, respectively (Table 14). The average coverage among years wasn t different (in north p=0.753, in south p=0.779 in both zones (Table 16). In north, the average coverage of perennial shrub Artemisia frigida was 5.7, 4.6 and 7.1% and while in south, 0.1, 0.1 and 0.1% in 2009, 2010 and 2011, respectively (Table 14). The average coverage of this species among years wasn t different (in north p=0.463, in south p=0.732) in both zones (Table 16). In north, the average coverage of palatable perennial grass species Stipa krylovii was 1.1, 0.8 and 2.3% while in south, 0.1, 0.1 and 0.2% in 2009, 2010 and 2011, respectively (Table14). The average coverage of this species among years wasn t different (in north p=0.691, in south p=0.600) in both zones (Table 16). In north, the average coverage of palatable perennial grass species Agropyron cristatum was 0.8, 0.3 and 1.1% while in south, 0.0, 0.0 and 0.1% in 2009, 2010 and 2011, respectively (Table 14). The average coverage of this species among years wasn t different (in north p=0.363, in south p=0.524) in both zones (Table 16). In north, the average coverage of palatable perennial grass species Leymus chinensis was 0.5, 2.1 and 3.6% in 2009, 2010 and 2011, respectively (Table 14). The average coverage of this species among years wasn t different (in north p=0.066, in south p=0.382) in north zones. In north, the average coverage of palatable perennial grass species Cleistogenes squarrosa was 0.4, 0.6 and 1.0% while in south, 0.0, 0.1 and 0.0% in 2009, 2010 and 2011, respectively (Table13.5). The average coverage of this species among years wasn t different (in north p=0.112, in south p=0.673) in both zones (Table 16). In north, the average coverage of palatable perennial grass species Achnatherum splendens was 0.0, 0.0 and 0.1% while in south, 1.1, 1.6 and 2.4% in 2009, 2010 and 2011, respectively (Table 14). The average coverage of this species among years wasn t different (in north p=0.405, in south p=0.754) in both zones. In north, the average coverage of unpalatable perennial shrub species Artemisia adamsii was 2.8, 0.9 and 2.8% while in south, 0.1, 0.2 and 0.2% in 2009, 2010 and 2011, respectively (Table 16). The average coverage of this species among years wasn t different (in north p=0.614, in south p=0.644) in both zones. In north, the average coverage of palatable perennial herb species Carex spp was 1.3,

99 and 3.2% while in south, 0.0, 0.2 and 0.2% in 2009, 2010 and 2011, respectively (Table 14). The average coverage of this species among years wasn t different (in north p=0.508, in south p=0.838) in both zones (Table 16). In north, palatable perennial herb species Allium Mongolichum was absent. While the average coverage of this species was 0.3, 1.5 and 6.3% in 2009, 2010 and 2011, respectively in south zone (Table 14). The average coverage of this species among years was significantly different (p=0.001) in south zone. In north, the average coverage of unpalatable annual herb Chenopodium acuminathum was 10.6, 8.9 and 21.9%, while was 5.5, 5.8 and 17.4% in 2009, 2010 and 2011, respectively in south zone (Table 14). The average coverage of this species among years wasn t different (p=0.053) in north zone while significantly different (p=0.000) in south zone (Table 16). As above result, the vegetation structure of north and south zone is different that means the species composition (TWINSPAN) and the average coverage (ANOVA) were different in such both zones. As affected the limited temporal precipitation changes the condition of vegetation is characterized which dominated by indicator species of typical steppe (north) and adapted in dry condition species of dry steppe (south). On the other hand, the limited temporal precipitation greatly was affected on this study area which distributed 450km width. Only, the palatable shrub Caragana microphylla weren t affected precipitation changes. The perennial palatable grass species were valuable fodder for livestock (by interview) and the abundance of these species significantly decreased from north to south while weren t changed among years. These species may be less drought-resistant resulting gradual recede when faced with increasing dryness. Moreover, Stipa krylovii is incapable of successive competition with drought resistant species in the south zone and can produce much seeds, but under the relatively dry conditions, seedlings are not commonly found and do not establish well (Staalduinen, 2005). As this precipitation changes, the south zone of central Caragana steppe of Mongolia characterized by with widely distribution perennial palatable (Allium Mongolichum) and annual unpalatable (Chenopodium acuminathum) herbs and with especial distribution perennial palatable grass (Achnatherum splendens). As the comparison of coverage of dominant species in north and south zone all dominant species which recorded in north zone weren t affected by annual changes while the significantly different species of Allium Mongolichum (p=0.033) and Chenopodomium acuminathum (p=0.000) in south zone (Table 16). It shown that, the condition of vegetation is more stable in north zone than south zone because of the most dominant 2 species were sensitive for rainfall variable. 99

100 The annual changes of weather condition did not affect on coverage of dominant species except Stipa krylovii in north zone. Stipa krylovii was weak significantly different in the north zone among census years (Table 18). But, in the south zone, the coverage of Allium mongolicum showed significantly different in the suppressed and endmost area. If the suitable condition continues for long period, other palatable species can regrow. 8. Grazing effect in local scale In order to be able to come to a sustainable management of the pastures and to combat the degradation of vegetation and desertification, a better understanding is needed of the role of herbivore in the sustainability of the ecosystem, and of the mechanisms underlying grazing effects on the vegetation. The changes in vegetation structure with the distance from the winter camp were classified into 4 types, which can indicate the species specific response to the difference of grazing pressure. The changes of coverage of dominant species from central part of winter camp with grazing gradient in 3 years were shown in Figure 18. The average coverage of palatable shrub Caragana microphylla has positive relationship with grazing distance in both zones during census years (Figure, ). Artemisia frigida was positive relationship with grazing distance (Figure, ). Grass palatable species Stipa krylovii and Agropyron cristatum`s the average coverage was with positive relationship with grazing gradient while other palatable grasses Leymus chinensis and Achnatherum splendens were with negative relationship with grazing gradient. Such trend of Leymus chinensis clear observed in north while Achnatherum splendens` was observed clear in south zone. It means that the winter camps which separated in north and south groups differenced by these 2 species at near the winter camp. In south, the Achnatherum splendens communities that were utilized by pastoralists during drought had the highest number of dung pellets and their species composition was affected by grazing impact (Sasaki, 2008). The cover of Achnatherum splendens, which has presented in highly productive areas (along drainage line) declined with grazing. Achnatherum splendens community can be key resource area in high variable rangelands and at the same time, grazing controls, such as limitation of the number of livestock in key resource areas, are needed for preventive managements. Caragana microphylla, Artemisia frigida, Stipa krylovii and Agropyron cristatum were palatable with high drought resistance (Fujita, 2012) and showed positive relationship with grazing pressure as shown in Figure

101 Almost all palatable species other than these species showed positive type of relationship with grazing gradient because of very high nutrient for livestock. Although Artemisia adamsii is unpalatable, it showed independent relationship with grazing gradient in all climate zones. (Figure, ). Carex spp is palatable but showed independent type of relationship with grazing gradient in all climate zones as shown in Figure , because of its unique distribution pattern scattering with annual patches. In other word, the types of relationship of vegetation coverage with grazing pressure of these two species were not affected by climate conditions. The covers of weedy annuals such as Chenopodium acuminathum increased abruptly along grazing gradient in our study site. Chenopodium acuminathum cannot appear the in the non-grazing plot (Kakinuma, 2013). In this study the average coverage of Chenopodium acuminathum was negative relationship with grazing gradient and the occurrence in endmost area was rare and shown the similar trend in both zones. Annual herbs could grow at nutrient-enriched habitat (Hilbig, 1995). As the amount of dung decreased with distance from winter camp (Okayasu unpublished data), annual herbs increased in its coverage markedly with increasing grazing pressure (Sternberg et al., 2000). The relationship between the vegetation coverage of the main species with distance from the winter camp was the same manner in north and south zones. Only the scale of coverage was different in both zones. As the relation PFT and relation types between average coverage and grazing distance the condition of vegetation around winter camp is illustrating by follows. Palatable shrub and grasses are increase in from winter camp and unpalatable annual species decrease with grazing gradient. Unpalatable independent species increase in far place or decrease in near the camp. Palatable independent species are increase in near the camp because of low palatability in comparison with palatable grass (Figure 25). Higher preference of livestock on palatable grass than palatable herb may allow surviving palatable herb under high grazing pressure, resulting independent change of palatable plant. 101

102 9. Other discussions 9.1 Shift of species composition Heavy grazing causes significant changes in vegetation. The vegetation degradation process is generally characterized by changes in PFT such as an increase in the abundance of annual species with a concomitant decrease in perennial species (Mclyntyre and Lavorel, 2001, Diaz et al, 2007) and several studies have also reported such trend in Mongolia (Fernandez-Gimenez and Allen-Diaz, 1999, Sasaki et al 2005). Vegetation changes along grazing gradient are frequently appeared in the changes of plant annuality, such as perennial species were apt to be replaced by annual species under heavy grazing pressure near the camps (Hoshino, 2009). Under long-term grazing pressure, most of Stipa which were the dominant grass of the original grassland vegetation were replaced by other grasses such as Cleistogenes squarrosa and Carex spp. Moreover, under much more degradation by heavy grazing, these secondary invaded grasses are eliminated by Artemisia frigida (Hilbig, 1995). 9.2 Shift from caespitose to rhizomatous In north zone, at the center of winter camp under heavy grazing pressure, rhizomatous plant such as Leymus chinensis could dominate but caespitose plant such as Stipa krylovii could not survive in such condition as shown in Figure 18-5 and Leymus chinensis could tolerate for grazing because of its tough underground system (Wang, 2004; Staalduinen and Anten, 2005). As a result, in north zone rangeland of Mongolia including this study area, increasing grazing pressure was because shifts of growth form from caespitose to rhizomatous. 9.3 After the secession of land use Even after the secession of grazing pressure by the decrease of livestock number or the establishment of protection area, grazing-sensitive PFT plants, such as palatable perennial grass, palatable perennial shrub and palatable perennial and annual herb, could not recover in abundance at the habitat used for long period with heavy grazing. Whereas, if the intensity of grazing pressure was not so severe, lightly affected, grazing-sensitive PFT plants could recover in abundance (Sasaki, 2007 ). 102

103 9.4 Countermeasure to grazing In species composition Plants in pasture must have some tolerance for grazing. Urtica has irritating trichomes on its stems and leaves, and the leaves of some Artemisia and Iris and the flowers of Taraxacum have a bitter taste. Potentilla has flat leaf rosettes to escape grazing and can be dominant in grazed pasture. However, this countermeasure reduces their competitive ability for light. Artemisia frigida, Poaceae, Carex and Allium are palatable and have a meristem at leaf base to ensure secondary and continuous growth even if the top of plant is grazed (Chognii, 2001). Low grazing pressure leads to reduce in vegetation coverage of Leymus chinensis which has flat leaves, while Stipa krylovii which has upright leaves to protect leaves from grazing can dominate (Staalduinen, 2005). Artemisia adamsii is unpalatable shrub because of its toxic oil (Jigjidsuren, 2003) and can dominate in alkaline soil (Hilbig, 1995). It can grow in degraded habitat disturbed by livestock tapping. Plants having chemical and physical protection for grazing can grow taller than grazed palatable plants (Staalduinen, 2005) Effect of site condition (nutrient) Annual herbs such as Chenopodium, Salsola and Artemisia increase their coverage as livestock density increase (Stenberg er al., 2000). Chenopodium acuminathum, unpalatable annual herb, can grow well at nutrient enriched sites (Hilbig, 1995), which reflect the habitat with much dung such as winter camp. Then this is the reason why higher coverage of Chenopodium acuminathum as the distance from the camp decrease (Okayasu, unpublished data). 9.5 Tolerance for grazing Plants having high tolerance for grazing and environmental disturbance increased their coverage near the winter camp. The vegetation coverage was higher in the north zone than the south zone (my observation). Peganum nigelastrum occurred mainly near the centre of winter camps in the south zone and mostly absent in the north zone (Table 8). The greater the grazing pressure results the coverage of Peganum nigelastrum is increasing. The changes in vegetation coverage of main species such as, Artemisia adamsii and Carex spp were with grazing gradient from winter camp was not different in the both areas. But, the importance of the main palatable species such as Achnatherum splendens was geographically 103

104 different, namely Achnatherum splendens is very important for livestock from winter to spring in the south zone but not so important in the north zone (my observation). The utilization of this species is different for livestock between the both areas. Achnatherum splendens can grow with shallow groundwater, although its habitat is mainly limited to degraded pasture. 9.6 Suppressed area and endmost site Difference in dominant species Experimental plots along the line from the winter camp were divided into two groups of the endmost site (endmost plot at 1600m from the winter camp) and others (plots from 25m to 800m) to clarify the effect of grazing on vegetation structure. Under heavy grazing pressure around sites in where livestock gathered, such as water sources (Stumpp et. al. 2005), livestock camps (Sasaki et al. 2008), and village centers (Fujita, 2012), unpalatable species such as Chenopodium acuminathum was increased under heavy grazing in near the winter camps in both zones (Figure, ). In near the winter camp in 25-50m, Leymus chinesis was much distributed in north zone while Achnatherum splendens was distributed in south zone. Peganum nigelastrum was increased under heavy grazing in south zone (Figure, 18-24). Difference in change between north and south In both suppressed area and endmost site, Caragana microphylla did not show any change of its coverage between the north and the south area as shown in Table 12, because of its high dominance in this study site. Except Achnatherum splendens and Chenopodium acuminathum, rest 8 species showed the same trend of coverage change between the north and the south zone in both suppressed area and endmost site. Most of them showed higher coverage in the north zone than the south zone. Only Allium mongolicum showed reverse trend. These trends were same in suppressed and endmost area with mean that may be, the coverage of these species in both zones related with precipitation changes (Table 12 and 13). In endmost site, Achnatherum splendens did not change its coverage between the north and the south zone, while in suppressed area, the coverage increased from the north to the south zone (Table 13). It related the different selection of location of winter camps in north and south zones. In north, the location of winter camp usually in far from Achnatherum community while in south located in inside of such community. As same as the case of Achnatherum splendens, Chenopodium acuminatum did not change its coverage between the north and the south zone in endmost site, but significantly decreased from the 104

105 north to the south zone in suppressed area (Table 13). As Chenopodium acuminathum is an unpalatable species, this change seems to indicate high grazing pressure in the north zone or low pressure in the south zone. 105

106 106

107 107

108 108

109 CONCLUSION As the number of total species composition and dominant species which recorded in study site, the number of species condition of steppe is not clear changing under grazing intensity. The aridity condition affects floristic composition resulting the transit zone between north and south zones. Important grass species for livestock are cannot grow well in south zone comparing with north zone. The dominant unpalatable and palatable species were same in north and south, while different species was dominant in transit zone. So, transit zone is very unique from north and south. The most dominant species in the south zone were significantly affected by temporal changes in vary rainfall condition. Four types of relation between species coverage and grazing distance were identified. All species of positive relation were palatable. A negative change was shown by a small proportion unpalatable species. Both unpalatable and palatable shrub and herb showed independent change. Higher preference of livestock on palatable grass than palatable herb may allow surviving palatable herb under high grazing pressure, resulting independent change of palatable plant. Grazing Management in rangeland of Mongolia My research identified that the transit zone between north and south zones which affected by aridity and overusing by pastoralists who escaped from drought and natural disaster and moved from south zone which high variable rainfall environment. I think that it is better to use around such zone with special suitable strategy which related vegetation condition, to control the number of livestock and movement of pastoralists in transit zone. Kakinuma (2013) resulted that the cover of key resource of Achnatherum splendens, which was present in highly productive areas declined with grazing and controlling livestock numbers remains indispensible to rangeland management, even in high variable environments. As the life strategy of pastoralist, I am thinking with combination such result it is better to protect of key resources of Achnatherum community from grazing like pastoralist who fenced of this community around winter camp in south zone. It will be best strategy to survival for newborn young animals and for produce of them when unexpected natural disaster especially in spring. As our result, the important fodder grass species for livestock are cannot grow well in south 109

110 zone comparing with north zone. The rangeland of south zone was characterized by Allium spp in normal and wet condition. Such pasture is suitable fodder for livestock during wet year because of most massive productive of Allium spp during growing season in south zone. Traditional grazing technologies, the taste of meat animals which grazed by Allium spp will delicious and livestock starts of get their weight and fattening in summer. I think that the pasture of south zone is suitable for livestock fattening in summer and possible receive the pastoralists from north when wet and good summer vegetation condition. It may will indispensable to protect the overusing in north zone during natural disaster at our study area. 110

111 ACKNOWLEDGEMENTS First of all, I am deeply grateful to my supervisor, Dr. Ken Yoshikawa for always supporting and leading me during my research. He always provided me with the best opportunities to develop my work and life condition, very warm energy and big power to overcome difficulty, the research preparation, experimental supports, writing paper, constant encouragement and invaluable discussion. I would like to express my gratitude to Dr. Undarmaa Jamsran and Dr. Bandi Namkhai who provided me the opportunity to study in Japan. They gave me many supports and always provided me with the energy to move on. I would also like to express my gratitude to second supervisor Dr. Keiji Sakamoto for the valuable suggestion to my work and insightful comments on my research. I am very grateful would like to specially express my gratitude to Dr. Nachinshonhor G. Urianhai, Dr. Muneto Hirobe, Dr. Naoko Miki and Dr. Yuko Miyazaki for the helpful discussion insight full comments and valuable books and advice with future potential on my study and thesis. For helpful supports and valuable discussion, I m very grateful to the members, of our laboratory Otoda Takashi, Yoshihiro Yamada, Yoshimori Ichido, Ogasa Mayumi, Yang Li, Tomohiro Teraminami, Monda Yuki, Junji Kondo, all members of our laboratory in Okayama University and students of Mongolian State University of Agriculture who participated in field survey in Mongolia. 111

112 REFERENCES 1. AIACC (Assessments of Impacts and Adaptations to Climate Change) (2006) Final report submitted to Assessments of Impacts and Adaptations to Climate Change. Project N-AS06, page Baker, L. E. and Hoffman, M. T. (2006) Managing variability: Herding strategies in communal rangelands of semiarid Namaqualand, South Africa. Human Ecology 34: Banzragch, D. (1970) Umard Khangain belcheer, hadlangiin urgatsiin dynamic, Ulaanbaatar. SHUA Cheng, Y. Tsubo, M. Ito, T. Y. Nishihara, E. and Shinoda, M. (2001) Impact of rainfall variablility and grazing pressure on plant diversity in Mongolian grassland. Journal of Aridland Environments, 75: Chognii, O. (2001) Mongoliin nuudleer ashiglagdsan belcheeriin oorchlogdoh, sergeh ontslog, Ulaanbaatar. 6. Dashnyam, B. (1974) Flora and the steppe vegetation of Eastern Mongolia. ANMNR. Ulaanbaatar. SHUA 147s (mong.) 7. Dashzeveg, L. (1986) Belcheeriin urgamliin idemj, tuunii mon chanar, SHUAmidral setguul. 8. Davaajamts, Ts. (1977) The pastures and mowing grassland of the northern part of the Uvurkhangai aimak by the Mongolian People`s Republic. Leningrad (russ.) 9. Davaajamts, Ts. and Sanchir, Ch. (1988) Belcheer ajiglah asuudliin uyaldaa, tejeeliin gol urgamluud. Huh hot. 10. Damiran, D. (2005) Palatability of Mongolian Rangeland Plants. Eastern Oregon Agricultural Research Center. 11. Diaz, S. Lavorel, S. Mclyntyre, S. Falczuk, V. Casanoves, F. Milchunas, D.G. Skarpe, C. Rusch, G. Sternberg, M. Noy-Meir, I. Landsberg, J. Zhang, W. Clark, H. Campbell, B.D. (2007) Plant trait responses to grazing: a global synthesis. Global Change Biology 13, Dorji, T. Fox, J. L. Richard, C. Dhondup, K. (2010) An assessment of Nonequilibrium Dynamics in Rangelands of the Aru basin, Northwest Tibet, China. Rangeland Ecology&Management 63:

113 13. Erdenejav, G. (1976) Baigaliin hadlan belcheeriig saijruulah arga. Ulaanbaatar. 86s. 14. Fernandez-Gimenez, M.E. and Allien Diaz, B. (1999) Testing non-equilibrium model of rangeland vegetation dynamics in Mongolia, Journal of Applied Ecology 36, Fernandez-Gimenezm M.E. and Allen-Diaz, B. (2001) Vegetation change along gradients from water sources in three grazed Mongolian ecosystems. Plant Ecology 157, Fujita, N. (2003) Sougen shokubutsu no seitai to yuubokuchi no jizokuteki riyou shokubutsugaku kara mita Mongoru kougen (Plant ecology of grasslands and sustainable use of nomadic pasturage a botanical view of the Mongolian plateau) Kagaku 73 (5): Fujita, N. and Amartuvshin, N. (2012) The Mongolian Ecosystem Network. 18. Jambal, S. and Batlai, O. (2008) Flowers of Hustai National Park. 19. Jigjidsuren, S. and Johnson, D. (2003) Forage Plants in Mongolia, Admon Publishing Co., Ulaanbaatar, Haase, G. (1983) Akademie Ved. In Geograficky Ustav eds., Physisch-geographische Studien in Asien. Brno, pp Hilbig, W. (1995) The vegetation of Mongolia. SPB Academic Publishing, Amsterdam. 22. Hill, M.O. (1979) TWINSPAN: a FORTRAN Program for Arranging Multivariate Data in an Ordered two-way Table by Classification of the Individuals and Attributes. Ecological and Systematic Department. Cornell University. New York Hoshino, A. Yoshihira, Y. Sasaki, T. Okayasu, T. Jamsran, U. Okuro, T. Takeuchi, K. (2009) Comparison of vegetation changes along grazing gradients with different numbers of livestock. Journal of Arid Environments 73, Grubov, V. I. (1955) Key to the Flora of Mongolia. Russia. 308c. 25. Grubov, V. I. (1982) Key to the vascular plants of Mongolia (with an atlas) Nauka. Leningrad: 441s. (russ.) 26. Gubanov, I. A. and Hilbig, W. (1993) Bibliographia phytosociologica:mongolia. Pars II. Exc.bot.Sect. B30: , Stuttgart, New York. 27. Kakinuma, K. Okayasu, T. Sasaki, T. Jamsran, U. Okuro, T and Takeuchi, K. (2013) Rangeland management in highly variable environments:resource variations across the landscape mediate the impact of grazing on vegetation in Mongolia. Grassland Science. 113

114 28. Kalinina, A.V. (1954) Statsionarnye issledovaniya pastbishch Mongolskoy Naradnoy Respubliki. Trudy Mong. Komiss. 60, Moskwa-Leningrad. 29. Kira, T. (1977) A climatological interpretation of Japanese vegetation zones. "Vegetation science and environmental protection" Tokyo. Maruzen Co. Ltd., Konagaya, Y. and Ai, M. (2003) Characteristic and Transfromation of the Pastoral system in Mongolia. The Mongolian Ecosystem Network. 31. Konagaya, Y. (2005) Sekai no shokubunka Mongoru (World Food Cultures: Mongolia) Tokyo:Nosangyoson Bunka Kyokai. 32. Laverol, S. Mchlntyre, S and Landsberg, J. (1997) Plant functional classifications:from general groups to specific groups based on response to disturbance. Trends Ecol Evol 12: Li, X. Xu, Z. (2012) Changes of species diversity in successional of plant community of abandoned land in typical steppe. Journal of Inner Mongolia Agricultural University Mack, N.R. and Thompson, N. J. (1982) Evolution in Steppe with few large, Hooved Mammals. The university of Chicago. 35. Mclntyre,? and Lavorel,? (2001) Livestock grazing in subtropical pastures: steps in the analysis of attribute response and plant functional types. Journal of Ecology 89, Miroshnychenko, Yu. M. (1967) Biologicheskaya produktivnost I vertikalnoe slojenie rastitelnoy massy nekotoryh fitotsenozov v Mongolskoy Naradnoy Respublike. Bot J.52: , Leningrad. 37. Nachinshonhor, G.U. (2008) Use steppe vegetation by nomadic pastoralist in Mongolia. The Mongolian Ecosystem Network. 38. Nakamura, T. Go, Y. Li, H. Hayashi, I. (1998) Experimental study on the effects of grazing pressure on the floristic composition of grassland of Bayinxile, Xilingole, Inner Mongolia. Vegetation Science 15, National Statistical Office of Mongolia (2003) Ulaanbaatar, Mongolian Statistical Yearbook. Ulaanbaatar. 40. National Statistical Office of Mongolia (2009) Ulaanbaatar, Mongolian Statistical Yearbook. Ulaanbaatar. 41. Pakeman, R. J. (2004) Consistency of plant species and trait responses to grazing along a productivity gradient: a multi-site analysis J Ecol 92:

115 42. Raffaele, E. and Veblen, T. (1998) Facilitation by nurse shrubs of resprouting behavior in a post-fire shrub land in northern Patagonia, Argentina. 43. Sambuu, J. (1945) Mal aj ahuidaa yaj ajillah tuhai ardad ogoh sanuulga surgaal, Ulaanbaatar. 44. Sanchir, Ch. and Badam, M. (1985) Urgamal tanih bichig, Ulaanbaatar Sanjid, J. (2012) Uur amisgaliin oorchloltoos urgamlan nomrog, urgamald uzuuleh noloo, dasan zohitsohiin sudalgaa tailan. 46. Sasaki, T. Okayasu, T. Takeuchi, K. Jamsran, U and Jadambaa, S. (2005) Patterns of floristic composition under different grazing intensities in Bulgan, South Gobi, Mongolia. Grassland Science 51: Sasaki, T. Okayasu, T. Shirato. Y. Undarmaa. J. Takeuchi, K. (2007) Quantifying the resilience of plant communities under different grazing intensities in a degraded shrub land: a case study in Mandalgobi, Mongolia. Grassland Science. 53, Sasaki, T. Okayasu, T. Jamsran, U. Takeuchi, K. (2008) Threshold changes in vegetation along a grazing gradient in Mongolian rangelands. Journal of Ecology 96, Sasaki, T. Okubo, S. Okayasu, T. Jamsran, U. Ohkuro, T. and Takeuchi, K. (2009) Two phase functional type redundancy in plant communities along a grazing gradient in Mongolian rangelands. Ecology, 90: Simukov, A. D. (1935) Pastbisha Mongolskoi Narodnoi Respubliki (Pastoral Movement in Mongolia). Sovremennaya Mongoliya 1935:2 (9), Smith, T. M. Shugart, H.H. and Woodward, F. I. (1997) Plant Functional Types: Their Relevance to Ecosystem Properties and Global Change. Cambridge University Press, Cambridge. 52. Staalduinen, van. M. A. (2005) The impact of herbivores in a Mongolian forest steppe. Utrecht University, Netherland. 53. Staalduinen, van. M. A and Anten, R. P. N. (2005) Difference in the capacity for compensatory growth of two co-occurring grass species in relation to water availability. Oecologia, 146, Stenberg, M. Gutman, M. Perevolotsky, A. Eugene, D. (2000) Ungar and Jaime Kigel Vegetation response to grazing management in Mediterranean herbaceous community: functional group approach. Journal of Applied Ecology, 37: Stumpp, M. Wesche, K. and Retzer, V. (2005) Impact of Grazing Livestock and Distance from Water Points on Soil Fertility in Southern Mongolia. Mountain Research and Development. 115

116 56. Su, Y. Z. Li, Y. L. Cui, H. Y. Zhao, W.Z. (2004) Influences of continuous grazing and livestock exclusion on soil properties in a degraded sandy grassland, Inner Mongolia, Northern China. Catena 59, Tomortogoo, O. Byamba, J., Badarch, G. (1983) Geological map of Mongolia, scale 1: Geological Survey of Mineral Resources Authority of Mongolia & Institute of Geology and Mineral Resources of Mongolian Academy of Science. Ulaanbaatar. 58. Tserenbaljid, G. (1972) Baigaliin elementuudiin gorimiin topology zui togtol, Mongol ornii oit heeriin lanshaptiin topology sudalgaa. Ulaanbaatar: 34c. 59. Tserendash, S. (1993) Pasture condition of Mongolia, research report, Mongolian National Scientific Academic journal, 25; Tserendash, S. (1995) Struktura produktivnosti I dimanika lugovoi I stepnoi pastitelnosti Severnoi chaste Mongolii. Pp Tserendash, S. (1996) Dynamica urojainosti lugoviih e steppnyh soobshestv nizovya basseina reka Selengi. Ulaanbaatar. 62. Tserendash, S. and Tserendeleg, J. (2000) Pasture condition, protection and use in Hustai National Park and its buffer zone. Ulaanbaatar, Hustai National park administration, MACNE. 63. Tserendash, S. (2006) Belcheer ashiglah onoliin undes (terguun devter). Ulaanbaatar. 64. Tuvshintogtoh, I. and Ariungerel, D. (2007) Degradation of Mongolian Grassland vegetation under overgrazing by livestock and its recovery by protection from livestock grazing. The Mongolian Ecosystem Network. 65. Ulziikhutag, N. (1985) Bugd Nairamdah Mongol Ulsiin belcher hadlan dahi tejeeliin urgamal tanih bichig. Ulaanbaatar Wang, R. Z. (2004) Responses of Leymus chinensis (Poaceae) to long-term grazing disturbance on the Songnen grassland of north-eastern China. Grass Forage Science 59, Wesche, K. Ronnenberg, K. Retzer, V. and Miehe, G. (2010) Effects of large herbivore exclusion on southern Mongolian desert steppe. Acta Oecologica-International Journal of Ecology, 36, Yamada, Y. Yasuto, Y. Hirobe, M and Yoshikawa, K. (2009) Environmental Factors Controlling Leaf Emergence in Caragana microphylla, Deciduous Shrub of the Mongolian Steppe. 69. Yunatov, A.A. (1946) Studies on vegetation of Mongolia during 25 years. In: Trudy Komiteta nauk MPR. Jubilee Series. 2:

117 70. Yunatov, A. A. (1954) Kormovye rasteniya pastbichi i senekosov Mongolskoy Naraodnoy Respubliki. Trudy Mong. Komiss. 56, Moskva-Leningrad. 71. Yunatov, A. A. (1976) Main features of vegetation cover of the Mongolian People Republic. Ulaanbaatar, Mongolia. 117

118 APPENDIX. The dominant species 118

119 119