Vegetative differences between the restored and native prairies at Stone Nature Center, Topeka, Kansas
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This study was conducted at Stone Nature Center in Topeka, KS. At the Stone Nature Center there are two prairies, one that is restored and one that is native. There should be no difference in the species richess or species evenness in the restored and native prairies. Thirty plots were surveyed in each prairie. The top three species in the Restored Paririe were, Andropogon gerardii (Big Bluestem), Andropogon scoparius (Little Bluestem), and Boutelua curtipendu (Side-Oats Gramma). The top three species in the Native Prairie were Andropogon gerardii (Big Bluestem), Ceanothus herbaceous (New Jersey Tea), and Andropogon scoparius (Little Bluestem). The Native Prairie had a larger diversity index than the Restored Prairie.
Introduction Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed (D'Antonio 2006). The type of management or restoration action employed will depend on the state of degradation of the ecosystem and the cause of degradation (Van Andel 2006). Common goals of ecosystem restoration are to increase diversity or control an overgrowth of specific plant species. At the Stone Nature Center in Topeka, Kansas there are two prairies, one that is an undisturbed native prairie and the other an area planted with warm season grasses in an attempt to restore native vegetation. The restored prairie was planted with a standard Conservation Reserve Program (CRP) grass mix. That mix contained Big bluestem (Andropogon gerardii), Little bluestem (Schizachyrium scoparium), Indian grass (Sorghastrum nutans), and Switchgrass (Panicum virgatum). No forbs were deliberately planted in the restored prairie. I compared the two prairies in terms of species composition and diversity and my hypothesis was that there would be no difference in species richness or species evenness between the restored and native prairies. Species richness is the number of species in a community and species evenness is the relative abundance of a species in a community (Molles 2008). Material and Methods The Stone Nature Center is found off 10th avenue just north of Interstate 70 (390 05’N. 950 78’ W.) in Topeka, KS (Fig. 1). Vegetation survey transects (200 m) were laid out north to south in the native prairie and east to west in the restored prairie in order to avoid mowed paths and survey both prairies at a topographic high. Fifteen,1m2 sampling plots were randomly placed on either side of the transect in each prairie. Aerial cover of each species encountered was recorded and the data was then put into an Excel spread sheet. From the raw data, I calculated species abundance, evenness, and richness. From this information I calculated the Shannon Weiner Diversity index (H’ = -Σ pi ln pi) and the Adjusted Floristic Quality Index (Adjusted FQI = meanC *sqrt N). Results Species composition and abundance In the restored prairie the most abundant species is Andropogon gerardii (Big bluestem) with 28.9 percent. The second most common species is Andropogon scoparius (Little Bluestem) at 15.1 percent. The third most common species is Boutelua curtipendual (Side-Oats gramma) with 11.3 percent.(Table 1) Andropogon gerardii (Big bluestem) is also the most common species in the native prairie covering 27.6 percent, but the woody shrub Ceanothus americanus (New Jersey Tea) is the second most common species with 16.5 percent. Andropogon scoparius (Little Bluestem) is the third most common species with 8.4 percent. (Table 2) Floristic Quality and species diversity The native prairie has more species and a greater evenness of species abundance than the restored prairie, giving it a higher diversity value. The native prairie has a richness of 32 species while the restored prairie has a richness of 25 species (Table 3). The native prairie’s species evenness is 0.64 while the restored prairie’s evenness is 0.55. The Shannon Weiner diversity for the native prairie is 2.21 while for the restored prairie it is 1.76. The restored prairie has significantly fewer species then the native prairie. The native prairie has more species making its abundance curve longer and greater a evenness which reduced the slope of the curve (Fig. 1). The calculated Adjusted Floristic Quality Index was 16 for the native prairie and 9 for the restored prairie (Table 3). Discussion The native prairie has greater species richness and a larger Shannon-Weiner diversity index. The species evenness is greater in the native prairie than the restored prairie. This information shows that the native prairie is more diverse then the restored prairie, rejecting my hypothesis. The native prairie also has a greater forb diversity while the restored prairie was mainly dominated by grasses. Management Ceanothus americanus, common name New Jersey Tea is a plant species that is consuming the native prairie at the Stone Nature Center. Ceanothus americanus is up to 1m tall and has multiple stems (Hilty 2010). These stems are light green in color and are covered with fine white hairs that become woody with age (Hilty 2010). This species also has small white flowers with five petals and a pleasant fragrance. The blooming period lasts a month after summer (Hilty 2010). The root system of this plant consists of stout deeply anchored reddish taproot (Hilty 2010). Ceanothus americanus is a plant species that can grow in almost any type of environment. The plant species can grow in drought conditions as well as wet conditions and is commonly found in soil that is rocky, silty or sandy. Ceanothus americanus will re-grow fine after a prairie burn (Hilty 2010). It may be that the current burn schedule is to frequent and therefore increasing the spread of this species. There are two possible solutions to control the over growth of Ceanothus americanus. The plant species can be sprayed with herbicides or one can stop burning the prairie for a few years. Most woody plants are susceptible to properly applied herbicides (Ohlenbusch1992). Ceanothus americanus would need to be cut and herbicide applied to the cut areas. Broadcast spraying is not recommended because it will damage the other species. This should prevent the plant from growing back, but this would take a great deal of time to herbicide all of the Ceanothus americanus in the native prairie. A more realistic approach to manage the Ceanothus americanus is to stop burning the native prairie. Since Ceanothus americanus can recover fast from burnings, not burning might stop some of the growth. The prairie should restart burning after 3 years and then start a burning program that is on an irregular schedule (pers comm. Sharon Ashworth). References D'Antonio, Carla, and Jeanne Chambers. Using Ecological Theory to Manage or Restore Ecosystems Affected be Invasive Plant Species. Washington DC: Island Press, 2006. Hilty, John. "New Jersey Tea". Prairie Wild Flowers of Illinois. March 10, 2010 <http://www.illinoiswildflowers.info/prairie/plant_index.htm#nj_tea>. Molles, Manuel. 2008.Ecology Concepts and Applications. 4th Edition. Ohlenbusch, Paul. Brush Management. Manhattan: Kansas State University, 1992. Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/ accessed [month/day/year]. Van Andel, Jelte, and James Aronson. Restoration Ecology. Oxford: Blackwell, 2006. Vegetative Differences between the Restored and Native Prairies at the Stone Nature Center Samantha Kriley, Dr. Sharon Ashworth Washburn University Table 1. Data from the restored prairie showing the most abundant species. Table 2. Data from the native prairie showing the most abundant species. Table 3. Diversity metrics comparing the native and restored prairies. Figure 1. Rank abundance curves of the native and restored Prairies. Andropogon gerardii (Big bluestem) Schizachyrium scoparium (Little bluestem) Bouteloua curtipendula (Side-Oats gramma) Ceanothus americanus (New Jersey Tea) Dale Dale A. Zimmerman Herbarium A. Zimmerman Herbarium Wasowski, Lady Bird Johnson Wildflower Center 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 abundance (relative % cover) Species rank restored prairie native prairie Native Prairie Restored Prairie Shannon Weiner Diversity Index 2.21 1.76 Richness 32 25 Evenness 0.64 0.55 Adjusted Floristic Quality Index 16 9 Restored Prairie Scientific Name Common Name % cover Andropogon gerardii Big Blue Stem 28.9 Schizachyrium scopariumLittle Blue Stem 15.1 Boutelua curtipendula Side-Oats Gramma 11.3 Scientific Name Common Name % cover Andropogon gerardii Big Blue Stem 27.6 Ceanothus americanus New Jersey Tea 16.5 Schizachyrium scoparium Little Blue Stem 8.4 Figure 1. Location of Study Site and survey transects. A native prairie in Manhattan, Kansas. http://www.ohio-nature.com/images/new-jersey-tea.jpg http://tiee.ecoed.net/vol/v3/issues/data_sets/konza/img/konza_landscape%5B HR%5D.jpg TM