Plants from high resource levels are typically fast-growers and rapid consumers of resources, while plants from low resource levels are slow-growers with conservative, efficient use of resources. In the proposed set of studies we will be determining the degree to which this general pattern holds for resources ranging from nutrients and water (below ground resources for plants) to light (an above ground resource). Our experiments will attempt to resolve some knotty questions about the general pattern of adaptation to low and high resources: Are the relationships described above caused by the environment, or is there a genetic basis to them? What genetic tradeoffs prevent simultaneous adaptation to both low and high resources? (i.e., why shouldn't a plant be both efficient and rapidly-growing?) Finally, can we demonstrate that natural selection acts on traits relevant to resource use, resource acquisition and growth in natural environments? The results of this research will have direct relevance to the impacts of humans on natural plant populations because the environmental perturbations caused by humans often directly or indirectly affect resource availability. In addition, our research is directed toward improving the mechanistic understanding of natural selection in wild plant populations, thus linking plant physiological ecology to plant population biology, two fields which have developed largely in isolation over the past three decades.//
