Plant Community Results from The Nature Conservancy s Dahms 2 Prairie Restoration By Chris Helzer (Location is the Central Platte River, Nebraska. Latitude 4.728787 Longitude -98.583755) This 69 acre former cropfield was broadcast seeded with approximately 2 plant species between December, 1999 and April, 2. The soil at the site is primarily 4-6 of sandy loam over sand, and groundwater is close enough to the surface in most years to support lowland tallgrass prairie plant species. In some portions of this restoration, wetlands were created through excavations that exposed groundwater. The spoil from those wetlands was formed into roughly linear sandy ridges. Every two years, data are collected from approximately 1 1m square plots stratified across the restored prairie. The plots are not in the same location each year, and are placed only in the mesic portions of the site (not in wetlands or sand ridges). From within each plot, a list of plant species is made. That species list allows a calculation of floristic quality for each of those plots (a combination of species richness and the average coefficient of conservatism* for each species). By averaging the floristic quality across all plots, the mean floristic quality for the entire site is calculated. That number, along with 95% confidence intervals (graph and error bars below) allows for detection of change in the restored plant community over time. *The coefficient of conservatism is a value assigned to each plant species (by local botanists) between and 1 that reflects the species ability to persist in various habitat conditions. Species found only in high quality habitats are assigned higher values than species that are also able to persist in more disturbed habitats (Swink and Wilhelm 1994). In Nebraska, for example, purple prairie clover is a 6 and yarrow is a 2. 1 8 6 4 2 Mean FQI In most similar restored prairies along the Central Platte River, mean floristic quality levels off after about four to six growing seasons. Interestingly, this restored prairie has continued to improve in terms of mean floristic quality through its first twelve growing seasons (so far). That this particular seeding has shown that continuing improvement is especially interesting because of its early history. This site was restored during the first part of a drought period that extended from late summer 1999 through about 25 or 26. As is typical of Platte River prairie restorations the second and third growing seasons were dominated by Canada wildrye. However, in this case, that wildrye period extended several more years, and we wondered whether the plant community would ever emerge from that period and become more diverse. Other nearby restorations, seeded in 1999, 21, and 22, did not exhibit the same long wildrye period.
The two graphs below show data pulled from the same plots from which mean floristic quality was calculated. The first graph shows the mean number of plant species per square meter (species density) increasing over time in a very similar pattern to that of mean floristic quality. The total of 12 plant species per square meter in 211 is one of the top species density numbers measured in any Platte River prairie remnant or restored. # of Species/Square Meter The bottom graph breaks down the same data into three categories of plant species: plants with low conservatism values (-3), high conservatism values (4-7), and invasive species. Invasives primarily include smooth brome, Kentucky bluegrass, and sweet clover. The lower C-value species in this restored prairie are dominated by species such as stiff goldenrod, tall boneset, and western yarrow. High C-value species include big bluestem, Canada milkvetch, Illinois bundleflower, and stiff sunflower. Values in all three categories appear to be increasing at similar rates. 12 1 8 6 4 2 Mean # Species/m 8 7 6 5 4 3 Number of Plant Species Per Square Meter by C-Value Category 4-7's -3's Invasives While increasing over time, the frequency of invasive species is still very low, especially relative to other nearby restored prairies of similar age. 2 1
Bromus inermis Smooth Brome 4 The frequency (% of 1 1m2 plots) of Poa selected pratensis plant species over Kentucky time - color Bluegrass coded. The most 1 abundant 1 species in each group Invasive are on Graminoids top, followed by the others in alphabetical order. Most perennial grasses are increasing over time (except Canada Wild Rye). Legumes have always been lower in abundance at this site Bromus inermis Smooth Brome 4 5 5 14 than nearby restored prairies but seem to be increasing slowly. Poa pratensis Kentucky Bluegrass 1 1 3 12 14 Perennial Graminoids Andropogon gerardii Big Bluestem 41 48 43 68 8 75-1% Elymus canadensis Canada Wild Rye 79 71 77 64 56 5-74% Sorghastrum nutans Indian Grass 12 16 32 55 25-49% 75-1% 1-24% Carex brevior Short-beaked Sedge 3 1 6 15 33 Carex gravida Heavy Sedge 2 1 1 5-74% 8 7 5-9% Eragrostis trichodes Tall Lovegrass 1 1 18 25-49% 23 21 2-4% Panicum virgatum Switchgrass 3 7 15 21 32 1% Pascopyrum smithii Western Wheatgrass 6 8 9 5 Schizachyrium scoparium Little Bluestem 12 3 8 14 17 Sporobolus compositus Rough Dropseed 6 16 11 24 35 Sporobolus cryptandrus Sand Dropseed 6 7 12 4 5 Perennial Forbs Solidago rigida Stiff Goldenrod 8 7 19 75 71 Monarda fistulosa Wild Bergamot 2 8 32 49 Helianthus pauciflorus Stiff Sunflower 6 17 33 41 42 Achillea millefolium Woolly Yarrow 1 27 22 33 41 Ambrosia artemisiifolia Common Ragweed 17 11 21 32 27 Ambrosia psilostachya Naked-spike Ragweed 1 13 15 25 Asclepias syriaca Common Milkweed 2 4 5 1 Asclepias verticillata Whorled Milkweed 1 4 8 1 Aster ericoides Heath Aster 8 1 1 2 12 Astragalus canadensis Canadian Milkvetch 2 8 9 8 Callirhoe involucrata Purple Poppy Mallow 1 2 1 6 1 Dalea candida White Prairie Clover 1 1 1 3 5 Desmanthus illinoensis Illinois Bundleflower 6 7 7 1 24 Eupatorium altissimum Tall Boneset 11 5 13 19 27 Helianthus maximilianii Maximillian Sunflower 2 3 23 19 13 Onosmodium molle False Gromwell 1 2 6 Physalis longifolia Ground Cherry 2 5 8 11 5 Ratibida columnifera Long-headed Coneflower 2 29 8 11 17 Rudbeckia hirta Black-eyed Susan 1 1 5 14 7 Silphium integrifolium Rosinweed 2 3 3 7 Solidago canadensis Canada Goldenrod 3 3 5 11 13 Verbena stricta Hoary Vervain 3 3 8 19 25 The high percentage of species that continue to increase in frequency each sampling period is very interesting. Only a few species are showing declines. The lack of dominance by perennial grasses in a restored prairie of this age is very unusual. The site has had some fire and grazing management, but less than other nearby restored prairies that are much more dominated by grasses.
Bromus inermis Smooth Brome 4 The frequency (% of 1 1m2 plots) of Poa selected pratensis plant species over Kentucky time - color Bluegrass coded. Among the 1 1 shorter-lived species, Invasive patterns Graminoids of frequency through time are more sporadic, with some increasing, others decreasing, and some just bouncing around. Non-native species are italicized. The two invasive grasses are Bromus inermis Smooth Brome 4 5 5 14 increasing through time, but still at very low levels, relative to other nearby restored prairies. Poa pratensis Kentucky Bluegrass 1 1 3 12 14 Annuals/Biennials Amaranthus sp. 2 2 6 3 2 75-1% 5-74% Ambrosia trifida Giant Ragweed 17 15 15 22 16 25-49% Bromus spp Annual Brome 1 8 75-1% 13 12 22 1-24% Cannabis sativa Hemp 3 9 5-74% 3 1 5-9% Chenopodium album Lamb's Quarters 29 21 725-49% 14 4 2-4% Chenopodium subglabrum Smooth Goosefoot 4 22 1 3 5 1% Cirsium altissimum Tall Thistle 1 3 5 21 Conyza canadensis Horseweed 76 4 69 19 4 Galium aparine Annual Bedstraw 6 2 3 4 Helianthus annuus Garden Sunflower 52 39 16 14 28 Hordeum jubatum Foxtail Barley 5 5 5 Lactuca ludoviciana Western Wild Lettuce 2 6 1 Lepidium densiflorum Small Pepper Grass 41 27 36 36 24 Lotus unifoliolatus Deer Vetch 1 1 2 8 9 Medicago lupulina Black Medick 18 6 12 7 Oenothera villosa Com. Evening Primrose 13 4 28 12 25 Oxalis stricta Yellow Wood Sorrel 5 14 26 34 5 Plantago patagonica Patagonia Plantain 5 1 8 9 11 Setaria sp. 16 13 19 6 5 Taraxacum officinale Common Dandelion 2 16 1 9 7 Tragopogon dubius Goat's Beard 1 7 3 3 6 Vulpia octoflora Six-weeks Fescue 4 1 3 6 13 Invasive Graminoids Bromus inermis Smooth Brome 4 5 5 14 Poa pratensis Kentucky Bluegrass 1 1 3 12 14 75-1% 1-24% 5-74% 5-9% 25-49% 2-4% 1%
Percent Frequency Percent Frequency The graphs on this and the following page display a subset of the plant species frequency values shown on previous pages. Nearly every species is increasing in frequency over time, with only a few short-lived weedy plants showing consistent decreases. Individual Plant Species Frequency Through Time 8 7 Solidago rigida Common Names (from top to bottom) 6 5 4 3 2 1 Monarda fistulosa Achillea millefolium Ambrosia psilostachya Verbena stricta - Stiff goldenrod - Bee Balm - Yarrow - Western Ragweed - Hoary Vervain 45 4 35 3 25 2 15 1 5 Individual Plant Species Frequency Through Time Helianthus pauciflorus Desmanthus illinoensis Astragalus canadensis Common Names (from top to bottom) -Stiff Sunflower -Illinois Bundleflower -Canada milkvetch
Percent Frequency Percent Frequency Individual Plant Species Frequency Through Time 9 8 7 6 5 4 3 2 1 Andropogon gerardii Panicum virgatum Sporobolus compositus Carex brevior Common Names (from top to bottom) - Big Bluestem - Switchgrass - Tall Dropseed - Short-beaked Sedge Individual Plant Species Frequency Through Time 8 7 6 5 4 3 2 1 Chenopodium album Conyza canadensis Common Names (from top to bottom) -Lamb s Quarters - Marestail
Plant Species List (as of June 211) Species Abutilon theophrasti Achillea millefolium Agrostis hyemalis Alisma subcordatum Allium canadense var. canadense Allium canadense var. lavendulare Amaranthus Amaranthus sp. Ambrosia artemisiifolia Ambrosia psilostachya Ambrosia trifida Ammannia coccinea Amorpha canescens Andropogon gerardii Antennaria neglecta Artemisia campestris Artemisia ludoviciana Asclepias incarnata Asclepias speciosa Asclepias syriaca Asclepias verticillata Aster ericoides Aster lanceolatus Astragalus canadensis Bolboschoenus maritimus Brassica sp. Brick ellia eupatorioides Bromus inermis Bromus japonicus Bromus tectorum Calamovilfa longifolia Callirhoe alcaeoides Callirhoe involucrata Calylophus serrulatus Cannabis sativa Carex brevior Carex gravida Carex pellita Carex scoparia Carex vulpinoidea Cenchrus longispinus Chenopodium album Chenopodium subglabrum Cirsium altissimum Cirsium arvense Cirsium flodmanii Cirsium undulatum Convolvulus arvensis Conyza canadensis Coreopsis tinctoria Crepis runcinata Cyperus schweinitzii Common Name Velvet-leaf Woolly Yarrow Winter Bentgrass Common Water Plantain Meadow Onion Meadow Onion Hybrid Pigweed Common Ragweed Naked-spike Ragweed Giant Ragweed Toothcup Lead Plant Big Bluestem Field Pussytoes Western Sagebrush White Sage Swamp Milkweed Showy Milkweed Common Milkweed Whorled Milkweed Heath Aster Panicled Aster Canadian Milkvetch Saltmarsh Bulrush False Boneset Smooth Brome Japenese Chess Downy Brome Sand Reed Pink Poppy Mallow Purple Poppy Mallow Yellow Evening Primrose Hemp Short-beaked Sedge Heavy Sedge Wooly Sedge Pointed Broom Sedge Fox Sedge Sandbur Lamb's Quarters Smooth Goosefoot Tall Thistle Canada Thistle Flodman's thistle Wavy-Leaved Thistle Field Bindweed Horseweed Plains Coreopsis Dandelion Hawks-beard Schweinitz's Flatsedge Total Species Number = 178
Plant Species List (as of June 211) Dalea candida Dalea purpurea Delphinium carolinianum Descurainia pinnata Desmanthus illinoensis Desmodium canadense Desmodium illinoense Digitaria cognata Digitaria sanguinalis Echinacea angustifolia Eleocharis elliptica Elymus canadensis Elymus trachycaulus Elymus virginicus Eragrostis trichodes Erigeron strigosus Eriogonum annuum Eupatorium altissimum Euphorbia maculata Galium aparine Gaura parviflora Gnaphalium obtusifolium Grindelia squarrosa Hedeoma hispida Helianthus annuus Helianthus grosseserratus Helianthus maximilianii Helianthus pauciflorus Helianthus petiolaris Helianthus tuberosus Heliopsis helianthoides Hesperostipa comata Heterotheca villosa Hibiscus trionum Hordeum jubatum Hordeum pusillum Juncus dudleyi Juncus torreyi Koeleria macrantha Lactuca ludoviciana Lactuca serriola Lactuca tatarica ssp. pulchella Lepidium densiflorum Lespedeza capitata Liatris punctata Liatris squarrosa Lithospermum caroliniense Lithospermum incisum Lolium arundinaceum Lotus unifoliolatus Lycopus americanus Lythrum alatum Medicago lupulina White Prairie Clover Purple Prairie Clover Carolina Larkspur Tansy Mustard Illinois Bundleflower Showy Tick Trefoil Illinois Tick Trefoil Fall Witchgrass Crabgrass Narrow-leafed Coneflower Northern Spikerush Canada Wild Rye Slender Wheatgrass Virginia Wild Rye Tall Lovegrass Daisy Fleabane Annual Eriogonum Tall Boneset Nodding Spurge Annual Bedstraw Small-flowered Gaura Old Field Balsam Curly-top Gumweed Rough Pennyroyal Garden Sunflower Sawtooth Sunflower Maximillian Sunflower Stiff Sunflower Petioled Sunflower Jerusalem Artichoke False Sunflower Needle-and-thread Hairy False Golden Aster Flower-of-an-hour Foxtail Barley Little Barley Dudley's Rush Torrey's Rush Junegrass Western Wild Lettuce Prickly Lettuce Blue Lettuce Small Pepper Grass Round-headed Bush Clover Dotted Blazing Star Scaly Blazing Star Puccoon Fringed Puccoon Tall Fescue American Bird's-foot Trefoil Common Water Horehound Winged Loosestrife Black Medick
Plant Species List (as of June 211) Melilotus albus Melilotus officinalis Mimosa quadrivalvis Mirabilis nyctaginea Monarda fistulosa Morus alba Muhlenbergia racemosa Oenothera laciniata Oenothera rhombipetala Oenothera villosa var. villosa Onosmodium molle Oxalis stricta Panicum oligosanthes Panicum virgatum Pascopyrum smithii Paspalum setaceum Penstemon digitalis Penstemon grandiflorus Physalis heterophylla Physalis longifolia Physalis virginiana Plantago patagonica Poa pratensis Polygonum lapathifolium Polygonum persicaria Polygonum sp. Populus deltoides Potentilla arguta Prenanthes aspera Ratibida columnifera Rosa ark ansana Rudbeck ia hirta Rumex crispus Salix exigua Salvia azurea Schizachyrium scoparium Schoenoplectus pungens Schoenoplectus tabernaemontani Scirpus atrovirens Senecio plattensis Setaria pumila Setaria sp. Silene antirrhina Silphium integrifolium Silphium laciniatum Solanum rostratum Solidago canadensis Solidago gigantea Solidago missouriensis Solidago rigida Sonchus arvensis Sorghastrum nutans Spartina pectinata White Sweet Clover Yellow Sweet Clover Sensitive Briar Wild Four-o'clock Wild Bergamot White Mulberry Upland Wild Timothy Ragged Evening Primrose Sand Primrose Common Evening Primrose False Gromwell Yellow Wood Sorrel Few-flowered Panic Grass Switchgrass Western Wheatgrass Slender Paspalum Foxglove Beard Tongue Large-flowered Beard Tongue Clammy Ground Cherry Ground Cherry Virginia Ground Cherry Patagonia Plantain Kentucky Bluegrass Heartsease Lady's Thumb Cottonwood Prairie Cinquefoil Rough White Lettuce Long-headed Coneflower Sunshine Rose Black-eyed Susan Curly Dock Sandbar Willow Pitcher's Sage Little Bluestem Three-square Bulrush Soft-stem Bulrush Dark Green Rush Prairie Ragwort Yellow Foxtail Sleepy Catchfly Rosinweed Compass Plant Buffalo Bur Canada Goldenrod Late Goldenrod Missouri Goldenrod Stiff Goldenrod Field Sow Thistle Indian Grass Prairie Cordgrass
Plant Species List (as of June 211) Sphenopholis obtusata Sporobolus compositus Sporobolus cryptandrus Taraxacum officinale Tradescantia bracteata Tradescantia occidentalis Tragopogon dubius Tridens flavus Triodanis perfoliata Typha angustifolia Ulmus pumila Verbascum thapsus Verbena hastata Verbena stricta Vernonia baldwinii Veronica peregrina Viola rafinesquii Vitis riparia Vulpia octoflora Xanthium strumarium Prairie Wedgegrass Rough Dropseed Sand Dropseed Common Dandelion Long-bracted Spiderwort Prairie Spiderwort Goat's Beard False Redtop Venus' Looking Glass Narrow-leaved Cat-tail Siberian Elm Common Mullein Blue Vervain Hoary Vervain Western Ironweed Puslane Speedwell Johnny Jump Up Riverbank Grape Six-weeks Fescue Cocklebur