Dissertation Research: Constraints and Drivers of Pinyon-Juniper Woodland Dynamics

University Of New Mexico, Albuquerque NM

Investigators

Abstract

0073139 Milne Understanding ecosystem responses to global climate change requires knowledge of both climatic constraints on the distribution of vegetation physiognomies and the demographic processes that drive plant migration. Using semiarid pinon-juniper woodlands as a study system, this dissertation research will examine the constraints and drivers of woodland dynamics in the context of long-term climatic variation. The research focuses specifically on climatic water balance as a constraint on woodland tree distribution, and seed production and bird-mediated dispersal as processes driving tree migration. The investigators will use remotely sensed tree cover estimates with a spatially explicit water balance model to test the hypothesis that climatic water balance constrains tree distributions. Using tree-ring data, the research will test whether seed production in a dominant woodland tree, Pinus edulis, is triggered by climatic fluctuations associated with the El Nino/Southern Oscillation. Finally, the links between pinon seedling establishment and caching behavior of its primary disperser, the Pinon Jay, will be investigated. Together, these studies will inform the development of a model of woodland dynamics. This research will increase our understanding of the complex spatio-temporal dynamics of ecosystems and potential responses to climate change