Understanding factors that regulate the composition and diversity of communities is a key aim in ecology, but is also necessary to anticipate and mediate impacts of environmental change on ecosystems. A long-term field experiment will be established to investigate the role of seed availability, local ecological interactions and chance factors in governing the dynamics of grassland communities along gradients of nitrogen fertilization. Experimental communities will be planted to establish a variety of initial conditions with respect to species diversity, composition and abundance. Once established, these communities will be exposed to varying levels of nitrogen fertilization to evaluate the extent to which fates of species and changes in the community are predictable based upon functional traits and initial population sizes of species.
The project will contribute to understanding of community formation along gradients of nitrogen availability, but also yield information applicable to grassland management and restoration. This project will contribute to education and training of female graduate students and undergraduates from University of Kansas (KU) and Haskell Indian Nations University. Minority students will present at meetings of the Ecological Society and the Society for Advancement of Chicanos and Native Americans. The project will be integrated into an existing public outreach program run by the KU Field Station.
We have established a long-term field experiment in tall-grass prairie vegetation to explore key questions in plant community ecology that have direct relevance to prairie restoration: 1) How do local competitive interactions and regional ecological processes such as dispersal limitation interact to regulate plant diversity? 2) How predictable are patterns of plant community development based on knowledge of the biology of the species involved? 3) How important are chance events and history in governing patterns of community development in response to environmental change? We planted a series of replicated experimental prairie communities in eastern Kansas to establish a wide variety of initial community states with respect to plant species number, species composition, and initial species abundances. Once fully established these experimental communities were exposed to varying levels of nitrogen fertilization. This experiment and associated studies permit tests of alternative models of ecological community organization and will provide results informative to practitioners of grassland management and grassland restoration. Preliminary findings indicate that the identity of species initially present in a given community, the prominence of particular plant traits and the action of chance events interact in complex ways to influence plant community development, biomass yield and the restoration of native plant diversity in developing grasslands. Continued work is focused on understanding how these different forces driving community development may vary along environmental gradients, over the course of succession or in response to habitat fragmentation. Results from these studies will be used to inform initial planting strategies for prairie restoration. The project has provided training and research opportunities for undergraduate and graduate students at the University of Kansas and has contributed to the development of outreach activities of the University of Kansas Field Station.
