Ectomycorrhizal fungi in dry and wet dipterocarp forests in northern Thailand - diversity and use as food

Transcription

1 Ectomycorrhizal fungi in dry and wet dipterocarp forests in northern Thailand - diversity and use as food 1 Dell B, 1,2 Sanmee R, 2 Lumyong P and 2 Lumyong S 1 School of Biological Sciences and Biotechnology, Murdoch University, Perth, Australia 2 Department of Biology, Chiang Mai University, Chiang Mai, Thailand Abstract Wild mushrooms are annually harvested for food from dry and wet dipterocarp forests of northern Thailand. Most of the species gathered fruit in association with host trees and form symbiotic associations know as ectomycorrhizas. This paper documents the diversity of ectomycorrhizal (ECM) fungi and collection as food. Forest fungi were collected from dipterocarp-dominated (mostly Dipterocarpus and Shorea spp.) primary and secondary forests in four provinces of northern Thailand, Chiang Mai, Chiang Rai, Mae Hong Son and Phayao Provinces, over three years. For comparative purposes, the diversity of larger fungi was also investigated in forests dominated by the Fagaceae or the Pinaceae. The dry dipterocarp forests had greater diversity of fruiting ECM fungi than the wet dipterocarp forests (11 families, 21 genera and 52 spp.; 8 families, 15 genera and 24 spp., respectively). The dominant genera in the dry dipterocarp forests were Russula (11 spp.), Boletus (7 spp.) and Amanita (5 spp.) whereas in the wet dipterocarp forests, Amanita (5 spp.) was the main genus followed by Lactarius = Russula (3 spp. each). Overall, ectomycorrhizal fungal diversity in dipterocarp forests (57 spp.) was intermediate between oak (161 spp.) and pine (15 spp.) forests. However, 65% of the ECM fungi that were associated with dipterocarps were not observed fruiting in other forest types. In the wet season, 19 ECM fungal species in ten genera were taken from dipterocarp forests (19 spp. from dry forests, 8 spp. from wet forests) by local people for sale in village, roadside and town markets. The market value of the most valuable fungus, the earth star (hed phor) Astraeus hygrometricus, ranged from Baht (7-10 US$)/kg. Aspects of fungal conservation and their use in reforestation are discussed. Introduction The uplands of Northern Thailand support a diverse mosaic of forest types determined principally by elevation, moisture and disturbance (Gardner et al. 2000). More than fourteen genera of forest trees have symbiotic associations with higher fungi in the region. Deciduous dipterocarps (dry dipterocarp forests) occur at low elevation ( m), on shallow soils (Khamyong et al. 1996), whereas the semi-evergreen dipterocarps (wet dipterocarp forests) occur on moist soils at mid-elevation ( m). The Fagaceae (Castanopsis, Lithocarpus and Quercus) are a dominant component of hill evergreen forests. Pinus kesiya and P. merkusii are locally prominent on dry sites at mid-elevation. A common feature of these forests is their dependence on ECM fungi for their growth and survival. 1

2 The Dipterocarpaceae are well-known as an ECM family of trees in SE Asia (e.g. Smits 1994, Lee et al. 1997). In spite of the likely importance of ECM fungi for the health of dipterocarp forests in northern Thailand, the subject has received little attention. There is no comprehensive higher fungal flora of Thailand though there are useful popular accounts of the more common species (Rachabunditayasathan 1996, Chansrikul 1998). Information on selected groups of fungi in northern Thai forests are available in Boonthavikoon (1998) and in unpublished theses including Konsab (1998), Phongmanee (1999), Phuthima (1999) and Tongglam (1999). Unlike for southwest China where the human use of forest fungi has been well documented, there is little information available on the extent and scope of mushroom collecting in northern Thailand (Dell et al. 2000). Furthermore, ethnobotanical studies in the region (e.g. Anderson 1993) have neglected the importance of forest fungi. The purpose of this paper is to begin the process of documentation of forest fungi in northern Thailand and their cultural value. Materials and methods Sporocarps of wild macro-fungi were systematically sampled from forests in Chiang Mai, Chiang Rai, Mae Hong Son and Phayao Provinces in northern Thailand, during the wet seasons (June-September) of The fungi were collected under ectomycorrhizal dipterocarps (Dipterocarpus alatus, D. costatus, D. obtusifolius, D. tuberculatus, D. turbinatus, Hopea odorata, Shorea obtusa, S. siamensis), oaks (Castanopsis acuminatissima, C. argyrophylla, C. armata, C. diversifolia, C. echinocarpa, C. ferox, C. indica, C. tribuloides, Lithocarpus polystachyus, L. tenuinervis, Quercus kerrii, Q. kingiana, Q. mespilifoliodes, Q. vestita), and pines (Pinus kesiya, P. merkusii). Specimens were photographed, their morphological and anatomical features described in detail (Sanmee 2004) and they were then lodged in the Fungal Herbarium of Chiang Mai University. Edible ECM fungi were observed in the Chiang Mai city market (Suthep), in road-side stalls of Weing Par Pao District in Chiang Rai Province, and in the local market (Mae Tam Market) in Phayao Province during the wet season in 1996 and Field collections were made at the following sites: A. Dry dipterocarp forests A1. Mae Wang Conservation Forest, Sanpanthong District, Chiang Mai Province. Elevation m asl. A2. Huay Hong Krai, Doi Saked District, Chiang Mai Province. Elevation ca. 400 m asl. A3. Doi San Phai, Ban Mae Sard, Chiang Rai Province. Elevation ca. 700 m asl. A4. Doi Pu Ya, Mae Hon Song Province. Elevation m asl. A5. Doi Kum Phra, Mae Hon Song Province. Elevation m asl. B. Wet dipterocarp forests B1. Near Phra-Tard-Doi-Suthep Temple, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation ca. 900 m asl. B2. Lum Namn Chiang Dao Research Centre, Chiang Mai Province. Elevation m asl. B3. Khun Chae National Park, ZZ Province. Elevation 900-1,000 m asl. 2

3 B4. Ban Huay Teecha, Soap Mei District, ZZ Province. Elevation ca. 800 m asl. B5. Doi Luang National Park, ZZ Province. Elevation m asl. C. Oak forests C1. Huay Kog Ma, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,000-1,300 m asl. C2. Sun Gu, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,400-1,500 m asl. C3. Khun Chang Kian, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,200-1,300 m asl. C4. Phar Dum, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation ca. 1,400 m asl. A2, B1 and B3. D. Pine forests D1. Yord Doi Pui, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,600-1,685 m asl. D2. Baw Gaow experimental station, Mae Hon Song Province. Elevation m asl. B1, B3 and B5. Results The diversity of ECM fungi fruiting in secondary and primary forests in northern Thailand was low under pines, intermediate under dipterocarps and high under oaks (Table 1). There were three times as many ECM fungal species fruiting under oaks than under dipterocarps. A total of 57 species of putative ECM fungi were collected under dipterocarps of which 65 % were not collected in other vegetation types suggesting preferential association of these species with dipterocarp hosts. The most abundant basidiomes were species of Amanita, Astraeus, Heimiella, Pterygellus, Mycoamaranthus and Russula. Three genera (Russula, Boletus and Amanita) dominated under dipterocarps contributing 42% of the diversity of ECM fungi compared to two genera under pines (Lactarius and Amanita with 60% of diversity) and four genera under oaks (Russula, Lactarius, Amanita and Boletus with 56.5% of diversity). The dry dipterocarp forests had greater diversity of fruiting ectomycorrhizal fungi (Table 2) than the wet dipterocarp forests (11 families, 21 genera and 52 spp.; 8 families, 15 genera and 24 spp., respectively). The percentage of fungal species restricted to dry or wet dipterocarp forests was ca. 63 or 21%, respectively. Overall, 19 species were collected in both wet and dry forest types. The dominant genera in the dry dipterocarp forests were Russula (11 spp.), Boletus (7 spp.) and Amanita (5 spp.) whereas in the wet dipterocarp forests, Amanita (5 spp.) was the main genus followed by Lactarius = Russula (3 spp. each). Edible forest fungi are routinely collected for food in Northern Thailand and sold in local markets. In the wet season, 19 ECM fungal species in ten genera were removed from dipterocarp forests (19 spp. from dry forests, 8 spp. from wet forests) by local people for sale in village, roadside and town markets. The fungi are mostly sold to local consumers in small quantities. However, the earth star (hed phor) Astraeus 3

4 hygrometricus is collected in large quantities and much is preserved in cans for domestic consumption as well as export. Currently, this is the most valuable fungus, and prices of fresh sporocarps ranged from Baht (7-10 US$)/kg. Discussion In terms of the presence of above-ground sporocarps of ECM fungi, the dry dipterocarp forests of northern Thailand have a much higher diversity than the wet dipterocarp forests. Furthermore, more than half of the ECM fungal species associated with dipterocarps did not fruit in the collection years in nearby forests dominated by ECM trees in the Fagaceae or Pinaceae. The ECM fungal flora of Thailand is still relatively poorly researched and new species of common ECM fungi continue to be described as groups are examined in more detail (e.g. Lumyong et al. 2003, Sanmee et al. 2003b, Kanchanaprayudh et al. 2004, Phosri et al. 2004). However, the number of putative ECM fungal species collected in this study compares favourably with results from other projects in the region. For example, Chalermpongse (1987) surveyed a dry-deciduous dipterocarp forest and a semi-evergreen dipterocarp forest in Amphur Pak Thong Chai and reported 35 species of ECM fungi fruiting over three years in the wet season. The deciduous forest had twice as many ECM species (29) as the evergreen forest. Smits (1994) collected over 80 species of putative ECM fungi in wet dipterocarp forests in East-Kalimantan. Overall, the diversity of ECM fungi in dipterocarp forests is lower than in temperate forests. Generally, the ECM fungi collected are consumed fresh within the Thai Provinces. The ECM fungi that are collected by local people in remnant primary and secondary stands of hill-side forests are sold in road-side, local (Fig. 1a) and city markets. Even in local markets, these wild mushrooms command higher prices than cultivated mushrooms, most vegetables or rice (Dell et al. 2000). People prefer to consume them due to their flavour and texture (Sanmee et al. 2003a). Although some species of Russula and Lactarius have a bitter flavour, local cuisine results in tasty dishes. According to Sanmee et al. (2003a), Astraeus hygrometricus is the most popular and the most expensive ECM fungus consumed in northern Thailand. It commands a high price because it is available early in the fungal fruiting season, is readily sold in the large cities, has desirable flavour and is processed in cans or bottles for export (40 oz = 40 baht, 70 oz = 60 baht) (Fig. 1b). For the other genera eaten, the price depends on the selling place, as wild ECM mushrooms in the city markets are more expensive than in the road-side or local markets. The latter markets occur in poorer socioeconomic areas and are closer to the collecting sites. Wild edible mushrooms were cheaper than cultivated mushrooms in 1994 (Jones et al. 1994), but they are now more expensive than cultivated mushrooms. The nutritive value of some of the ECM fungi from northern Thailand have recently been determined (Sanmee et al. 2003a), and they compare favourably with cultivated mushrooms. Edible ECM fungi are also collected from under oaks and pines in northern Thailand. The number of edible species collected (under oaks > under dipterocarps > under pines) reflects the relative diversity of ECM fungi referred to earlier. However, Boonthavikoon (1998) reported that there were more species of edible fungi in Pinus kesiya plantations than in the natural forests. The wild ECM fungi are generally sold as presentation plates of single species and non ECM forest mushrooms are sold 4

5 alongside. The latter include several species of Termitomyces that fruit in association with underground colonies of termites. The wild mushroom collectors make skilful use of the knowledge transmitted down orally from their ancestors. In the city, the workers travel to the mountains for collecting mushrooms from early morning ( h) until the afternoon ( h). During this period, traders wait at designated locations and the collectors take the mushrooms from the forest to the traders at regular intervals. The traders transport the mushrooms to sale in the city market markets. In the rural areas, the collectors and the traders are often a single family, usually from one of the Hill Tribes in the region. Often the husband is the collector and the wife conducts sales at the side of the road (Sanmee et al. 2003). As the human population increases in Northern Thailand the pressures on remnant vegetation and the conservation estate will become more severe. Potential damaging impacts of over-harvesting of fungi include soil erosion and loss of biodiversity (Dell et al. 2000). Research into the biology of edible ectomycorrhizal and other forest fungi is still at its infancy in Thailand. There is a need for ethnomycological, ecological and fungal conservation studies. Burning of dry dipterocarp forests is thought to promote higher yields of mushrooms such as hed phor and some communities therefore use yearly firing. Fire may also be used so people can easily find hed phor on the soil surface. The impact of fire frequency on soil erosion, biodiversity, and other factors needs careful study. In the long term, it is anticipated that some of the more valuable edible forest fungi will be able to be grown using suitable host trees in agroforestry systems. This should reduce some of the pressure off key conservation areas and at the same time allow the local hill tribes to continue to collect for their own use. However, before this can be achieved, a small number of target fungi will need to be identified for commercialisation, and culture and inoculation systems developed for local conditions. At the same time, use of ECM fungi should be encouraged as standard practice in all land restoration and reforestation projects where ECM hosts are present. For this to be effective, investigations into the host range, associated microflora, inoculum production and site conditions favourable for fungal growth and fruit body formation are required. References Anderson, E.F Plants and People of the Golden Triangle. Ethnobotany of the Hill Tribes of Northern Thailand. Dioscorides Press, Portland. Boonthavikoon, T Diversity of mushrooms in the natural pine-deciduous dipterocarp forest and pine plantation in Chiang Mai, Northern Thailand. Thai Forest Bulletin Botany 26: Chalermpongse, A Mycorrhizal survey of dry-deciduous and semi-evergreen dipterocarp forest ecosystems in Thailand. In: Kostermans AJGH. (ed) Proceedings Third Round Table Conference on Dipterocarps, Bogor, Indonesia April 1985, pp UNESCO, Jakarta. Chansrikul, A Mushrooms of Thailand. 6 th ed., Thai Watthanapanich Printing Ldt., Bangkok. (in Thai). Dell, B., Malajczuk, N., Dunstan, W., Gong, M. Q., Chen, Y. L., Lumyong, S., Lumyong, P., Supriyanto & Ekwey, L Edible forest fungi in SE Asia - current practices and future management. In Proceedings of the International Workshop Biotechnology Applications for Reforestation and Biodiversity Conservation, Nepal, 1999, BIO-REFOR, pp

6 Gardner, S., Sidisunthorn, P. & Anusarnsunthorn, V A Field Guide to Forest Trees of Northern Thailand. Asia Books Co., Ltd., Bangkok. 560 pp. Jones, E. B. G., Whalley, A. J. S. & Hywel-Jones, N. L A fungus foray to Chiang Mai market in northern Thailand. The Mycologist 8: Kanchanaprayudh, J., Zhou, Z., Yomyart, S., Sihanonth, P., Hogetsu, T. & Watling, R A new species of Pisolithus abditus, an ectomycorrhizal fungus associated with dipterocarps in Thailand. Mycotaxon 88: Khamyong,S., Pramprasit, S. & Pinthong, J The relationship between plant associations and soil characteristics in a dry dipterocarp forest in Thailand. In: Appanah,S., Khoo, K.C. (eds) Proceedings Fifth Round Table Conference on Dipterocarps, ChiangMai, Thailand, 7 10 November 1994, pp FRIM, Kuala Lumpur. Konsab, D Diversity of agaric mushroom at Huay Kog Ma, Doi Suthep-Pui National Park. Master s Thesis, Chiang Mai University, Chiang Mai. (in Thai). Lee Su See, Alexander, I.J. & Watling, R Ectomycorrhizas and putative ectomycorrhizal fungi of Shorea leprosula Miq. (Dipterocarpaceae). Mycorrhiza 7: Lumyong, S., Sanmee, R., Lumyong, P., Yang, Z.L. & Trappe, J.M Mycoamaranthus cambodgensis comb. nov., a widely distributed sequestrate Basidiomycete from Australia and Southeastern Asia. Mycological Progress 2: Phongmanee, W Diversity of macrofungi on soil at the evergreen hill forest in Doi Suthep-Pui National Park, Chiang Mai Province. Master s thesis, Chiang Mai University, Chiang Mai (In Thai). Phosri, C., Watling, R., Martin, M.P. & Whalley, A.J.S The genus Astraeus in Thailand. Mycotaxon 89: Phuthima, N Collection and Cultivation of Macrofungi from Doi Suthep-Pui National Park. Master s thesis, Chiang Mai University, Chiang Mai (In Thai). Rachabunditayasathan Edible and Poisonous Mushrooms in Thailand. Amarin Co. Printing and Publishing, Bangkok. (in Thai). Sanmee, R., Dell, B., Lumyong, P., Izumori, K. & Lumyong, S. 2003a. Nutritive value of popular wild edible mushrooms from Northern Thailand. Food Chemistry 82: Sanmee, R., Yang, Z.L., Lumyong, P. & Lumyong, S. 2003b. Amanita siamensis, a new species of Amanita from Thailand. Mycotaxon 88: Smits, W.T.M Dipterocarpaceae: Mycorrhizae and Regeneration. Tropenbos Series 9, Wageningen. Tongglam, S Diversity of Boletes in Doi Suthep-Pui National Park, Chiang Mai Province. Master s Thesis, Chiang Mai University, Chiang Mai (in Thai). 6

7 a b Figure 1. a. Stall in Mae Tam market in Phayao Province selling wild edible mushrooms in northern Thailand. b. Astraeus hygrometricus preserved in saline solution. c 7

8 Table 1. Comparison of the number of putative ECM fungal species associated with diterocarp, pine and oak forests in northern Thailand. Fungal taxon Dipterocarp forest Oak forest Pine forest Amanitaceae Amanita 6 (1)* 19 3 Bolbitiaceae Hebeloma 1 Boletaceae Austroboletus 1 Boletellus 1 (1) 3 Boletochaete 1 (1) Boletus 7 (5) 16 Gastroboletus 1 (1) Heimiella 19 (1) 1 Leccinum 1 Phylloporus 1 (1) 3 Pulveroboletus 2 Sinoboletus 2 (2) Strobilomyces 5 Tylopilus 4 Xerocomus 2 (2) 3 Boletinellaceae Boletinellus 1 1 Phaeogyroporus 1 Cantharellaceae Cantharellus 2 (2) 2 Craterellus 3 cf. Pterygellus 1 (1) Clavulinaceae Clavulina 1 (1) Cortinariaceae Aroramyces 1 Cortinariaceae Cortinarius 8 Inocybe 4 (1) 7 1 Entolomataceae Clitopilus 1 (1) Entoloma 1 4 Hydnaceae Hydnum 1 Hydnangiaceae Laccaria 3 2 Hymenochaetaceae Coltricia 1 8

9 Hymenogasteraceae Mycoamaranthus 1 (1) Paxillaceae Gyrodon 1 Ramariaceae Austrogautieria 1 (1) 2 Ramaria 2 Russulaceae Lactarius Russula 11 (8) 34 1 Sclerodermataceae Astraeus 1 (1) Pisolithus 3 (2) 1 Scleroderma 3 (2) 1 1 Suillaceae Boletinus 1 Fuscoboletinus 1 (1) Thelephoraceae Thelephora 3 Tricholomataceae Hygrocybe 1 Lepista 1 Tricholoma 1 Total species 57 (37)* * The number in brackets indicates species associated only with dipterocarps in northern Thailand 9

10 Table 2. Diversity and number of species of putative ECM fungi fruiting in dry and wet dipterocarp forests in northern Thailand. Family Genus Dry forest Wet forest Amanitaceae Amanita 5 5 Boletaceae Boletellus 1 1 Boletochate 1 Boletus 7 1 Gastroboletus 1 1 Heimiella 1 Phylloporus 1 1 Sinoboletus 2 Xerocomus 2 Cantharellaceae Cantharellus 2 1 Pterygellus 1 1 Clavulinaceae Clavulina 1 Cortinariaceae Inocybe 2 2 Entolomataceae Clitopilus 1 Entoloma 1 1 Hymenogasteraceae Mycoamaranthus 1 Ramariaceae Austrogautieria 1 Russulaceae Lactarius 4 3 Russula 11 3 Sclerodermataceae Astraeus 1 1 Pisolithus 3 1 Scleroderma 3 Suillaceae Fuscoboletinus 1 Total species

11 Table 3. List of common edible ectomycorrhizal mushrooms collected by local people in secondary and primary dipterocarp forests in northern Thailand. Scientific name Thai name Dry dipterocarp forest Wet dipterocarp forest Amanita chepangiana Hed kai kao + + A. hemibapha Hed kai laung + + Astraeus hygrometricus Hed Phor + + Boletus firmus Hed namn phung + Cantharellus cibarius Hed kamin yai + + Cantharellus minor Hed kamin lek + Heimiella subretispora Hed pord mah + Lactarius glaucescens Hed Khar + L. piperatus Hed khing + L. subpiperatus + L. volemus Hed farn + Hed kalum mahr + Mycoamaranthus cambodgensis Pterygellus polymorphus Hed kamin noi + + (aff.) Russula alboareolata Hed namn pang + + R. cyanoxantha Hed num mark + R. virescens Hed lom kra khiao + + Russula sp.1 Hed poong moo dum + Russula sp.2 (red) Hed daeng + + Sinoboletus sp. Hed pord mah lek + 11