The investigators aim to explain a broad-scale pattern of plant species dominance that is repeatedly found among native plant communities occupying abandoned agricultural fields of the eastern U.S. They will test a simple and elegant theory of resource competition (Tilman's R*) that predicts that the dominant species in any community is the species capable of reducing the most limiting, or sought after, resource (i.e. water, nitrogen, or light) to a critically low level, causing other species' populations to decline. This research will also attempt to determine how herbivores and other factors may alter the outcome of competition by affecting the ability of competing plant species to use the limiting resource. In other words, the investigators will combine the effects of numerous factors (i.e. herbivory or disease) known to influence plant community structure (diversity, relative abundance) into one simple measure: the amount of resource a species requires. If successful, multiple processes in complex communities of organisms can be measured via a common currency (a resource), greatly increasing the ability to predict change.
Broader impacts: This research has strong ecological and economic applications. Prospective results may influence methods of controlling and predicting the spread of invasive species, provide key insights into conservation methods for rare and endangered species, and aid in predicting the success of habitat restoration. This research also has the potential to predict how plant communities (natural, agricultural, and commercial) will respond to rapidly changing resource regimes resulting from global climate change and other anthropogenic influences.
