2000 Progress Report: Methods for Increasing Biodiversity in Tallgrass Prairie ReconstructionsEPA Grant Number: R825796
Title: Methods for Increasing Biodiversity in Tallgrass Prairie Reconstructions
Investigators: Jurik, Thomas W. , Moloney, Kirk
Institution: Iowa State University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1998 through December 31, 2000 (Extended to September 30, 2001)
Project Period Covered by this Report: January 1, 1999 through December 31, 2000
Project Amount: $243,019
RFA: Ecosystem Restoration (1997) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Hazardous Waste/Remediation , Land and Waste Management , Ecosystems
Objective:The prairies of the midwestern United States have largely been destroyed and replaced by agricultural fields. However, we are now much more aware of the value of the prairie ecosystem as an environmentally stable landscape that provides a variety of environmental, economic, and aesthetic benefits. Thus, there is widespread interest in reconstructing prairie vegetation, both in large tracts and along roadsides. However, many prairie species, particularly species other than grasses (forbs), are relatively difficult to establish from seed, which is usually the only feasible method of planting. This project is investigating methods of increasing plant diversity in prairie reconstructions, with emphases on seeding and management techniques and incorporation of minor disturbances and natural spatial patterns into the reconstruction process.
This project is investigating the impact of several factors on species diversity during prairie reconstructions, including: (1) different methods of planting seeds, (2) plant height at mowing (to reduce competition from weeds) during the first three seasons after planting, (3) the introduction of minor disturbances as sites for establishment of forb seedlings in grass-dominated areas, and (4) introduction of spatial patterns found in natural prairies. Field studies were conducted at Neal Smith National Wildlife Refuge?Prairie Learning Center near Prairie City, IA, where reconstruction of an extensive (3500 ha) prairie is underway.
Experiments 1 and 2. In 1998, we began our tests of different methods of planting seeds and of different mowing treatments by establishing two experiments in which seeding treatments (planting at different depths) were combined with a set of mowing treatments (mowing to various heights when the vegetation reached a given height or mowing to a fixed height when the vegetation reached various heights). In 1999, we continued to monitor these plots, although the experimental design was changed slightly from our original plan. In 1999, we subdivided each replicate plot into two subplots. For one of the subplots in each plot, mowing treatments were continued according to our original plan. The other subplot was not mowed in 1999. In 2000, mowing on some of the remaining replicates was discontinued. This strategy allows us to introduce a new factor into our experiments, namely, the number of years a plot is mowed. At end of 2000, we have plots that have been mowed 0, 1, 2, or 3 years. The current treatments thus enhance the scope of our original plan, at the cost of using somewhat smaller replicate plots. Vegetational composition in subplots of each plot was recorded beginning in September; summarization and analyses of results are presently underway.
Experiment 3. Our third main experiment investigates the effects of small-scale disturbance on species diversity of prairie reconstructions, particularly on sites that are several years old (after planting). In 1998, three blocks of six plots, on each of two sites, were established. Artificial gopher mounds (total of 1,728 mounds) were established on the plots in July-September 1998. In December 1998, seeds of seven conservative native forb species were planted on and off the artificial mounds. The plant species include rough blazing star (Liatris aspera Michx.), prairie coreopsis (Coreopsis palmata Nutt.), pale purple coneflower (Echinacea pallida Nutt.), purple prairie clover (Dalea purpurea Vent.), leadplant (Amorpha canescens Pursh), prairie violet (Viola pedatifida G. Don), and alumroot (Heuchera richardsonii ). In summer 1999, seedling production and survival were monitored at three-week intervals on planted mounds, unplanted mounds, planted off-mound sites, and unplanted off-mound sites, to determine the effect of mounds on recruitment and survival. During July and August 1999, another1,728 mounds were constructed in various spatial and temporal patterns relative to the mounds established in 1998. Seeds were planted on and off these mounds in late 1999. Throughout the 1999 and 2000 growing seasons, the vegetation growing on a subset of mounds and off-mound sites was surveyed periodically. Several experiments to assess potential seedling herbivore populations were also conducted in 1999 and 2000. We are currently analyzing the data and writing manuscripts.
Experiment 4. Our fourth major focus involved measurement of spatial patterns in native communities. We investigated eight potential sites in south-central Iowa during May and June 1999. Unfortunately, most of the sites were so disturbed and/or fragmented as to be unusable. One suitable site was sampled in 1999, using closely-spaced 50 x 50 cm plots along transects of 100-200 m. In 2000, eleven 50-m transects distributed over three prairies (Sheeder, Bundt, and Morris prairies) were sampled (total of 1,100 quadrats). Data analyses are currently underway.
Future Activities:Field studies and data collection have been completed. We will spend the next several months analyzing data and writing manuscripts.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 16 publications||4 publications in selected types||All 4 journal articles|
||Jurik TW, Kliebenstein H. Canopy architecture, light extinction and self-shading of a prairie grass, Andropogon gerardii. The American Midland Naturalist 2000;144(1):51-65.||