LTER Cross-site: Collaborative Research - Assessing the Geographic and Temporal Consistency of Life History and Demographic Patterns: A Long-term, Multi-site Comparison

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

0087078 Doak Ecologists increasingly understand the importance of spatial variability in natural systems, a recognition that led to the creation of the LTER network. However, we still know surprisingly little about spatial variation in the demography of individual species, creating an important gap in knowledge for both applied and basic ecology. The paucity of full demographic studies that span multiple populations across substantial geographic scales creates two general problems. First, population biologists are forced to extrapolate from the population dynamics and life history patterns found in single, well-studied populations to those occurring in distant parts of a species range. Such extrapolation is commonplace in conservation biology, comparative life history analysis, and climate change predictions, and is currently done with little understanding of how much spatial variation actually exists in the demography of individual species. Second is the question of what sets the range limits of species. While the physiological effects of climate are often well-known, the lack of broad-scale demographic studies makes it less clear how population dynamics vary near range limits, and thus the extent to which poor demographic performance versus other proposed factors, such as metapopulation dynamics, determine the distributional limits of species. As a result, we have little ground for building mechanistic predictions about how species ranges will shift as climate changes.