This research will continue and extend the analysis of the relationship between vegetation pattern (species or lifeform composition, size structure) and ecosystem processes (nutrient cycling and water relations). This project has as its nucleus a set of interacting models that couple ecosystem processes to vegetation dynamics through growth, mortality, and regeneration of individual plants. The models will be implemented and tested at several sites, each a member of NSF's Long-Term Ecological Research (LTER) network, which represent a range of forests and grasslands arrayed along continental-scale temperature and precipitation gradients. Analyses will focus on two goals that are fundamental to ecosystem science and developing global environmental concerns: (1) to account for existing patterns in vegetation and ecosystem processes under current environmental regimes; and (2) to assess the potential responses of ecosystems to environmental variability, especially anthropogenic climate change. This project will contribute substantially to ecosystem science by further elucidating the "pattern-process" paradigm as applied to feedbacks among plant-demographic mechanisms, water relations, and nutrient cycling; and by providing a synthesis of these relationships over a broad spectrum of ecosystems but within a common framework. The project will also further develop networking capabilities among collaborating scientists.
