Thursday, August 7, 2008

PS 67-155: Investigating the role of prairie soil inoculum and distance to inoculated plants in tallgrass prairie restoration

Elizabeth Middleton, James D Bever, and Peggy A Schultz. University of Indiana

Background/Question/Methods

Restoration practitioners have been successful in restoring native dominance but not the original diversity of tallgrass prairie.  Poor representation of late successional species in restoration may be due to the absence of their required soil mutualists.  The aim of this project is to use the prairie soil community and the nucleation model of succession to increase establishment and survival of later successional plant species.  In the nucleation model of succession, one plant colonizes a new area and facilitates the establishment of other individuals.  The ‘nucleation center’ expands and a plant community develops. 

This project examines if using the prairie soil community as a nucleus will increase small scale plant diversity.  The nucleation model of succession is applied by planting inoculated plants (nurse plants) as vehicles for the establishment of the soil community from prairie remnants and an old field.  Later successional plant species (test plants) are planted at varying distances from the nurse plants.  The test plants are used to test whether the introduced prairie soil community aids in the survival and growth of these species. 

Results/Conclusions After the first growing season, survival for nurse plant species was greater than 92% for all species.  Survival of Purple Prairie Clover (Petalostemum purpureum) was predicted by distance and presence of nurse plants and its’ growth was higher with prairie inoculum.  Survival of Scribner’s Panic Grass (Panicum oligosanthes) was partially attributed to a three way interaction with distance, inoculum source, and presence of nurse plants.  Growth of Prairie Dropseed (Sporobolus heterolepis) was predicted by an interaction between distance and inoculum source.  

The results from the first growing season suggest that the introduction of prairie inoculum into restorations could facilitate establishment and growth of certain prairie species.