9615313 Whitham Studies of natural perturbations help understand how plants ecologically and/or evolutionarily respond to climate change. Since the eruption of the Sunset Crater in about 1300AD, colonizing plants have had only a few hundred years to adapt to this hotter, dryer, and nutrient poor cinder environment. This LTREB project represents a continuation of a 15 year study on how these environmental stresses have affected pinyon pine and its dependent community members. Compared to trees growing in low stress sandy-loam soils, trees growing in cinders produce less defensive resin, suffer chronic insect outbreaks, and suffer corresponding declines in mycorrhizal mutualists, growth and cone production. This in turn affects birds and mammals dependent upon pinyon seeds for their survival. Associated changes in tree genetics suggest that the selection pressures imposed by this new environment have resulted in genetic adjustments in the plant population. The distributions of dependent mycorrhiza, arthropods, and vertebrates map onto the underlying genetic structure of the plant population. Because the southwest has experienced general warming since the beginning of record keeping and is currently suffering a 100-year record drought, by contrasting Sunset Crater with adjacent less stressed control sites, the PI's can address the question, "Is Sunset Crater an analogue to global climate change and if so, how can it be used to predict the ecological and evolutionary impacts of continuing warming trends?" The continuation of long-term monitoring of individual tress and the associated long-term experiments will provide a clear answer to this important question.
