Historical and Modern Disturbance Regimes, Stand Structures, and Landscape Dynamics in PiÃ±onâ€“Juniper Vegetation of the Western United States
PiÃ±onâ€“juniper is a major vegetation type in western North America. Effective management of these ecosystems has been hindered by inadequate understanding of 1) the variability in ecosystem structure and ecological processes that exists among the diverse combinations of piÃ±ons, junipers, and associated shrubs, herbs, and soil organisms; 2) the prehistoric and historic disturbance regimes; and 3) the mechanisms driving changes in vegetation structure and composition during the past 150 yr. This article summarizes what we know (and don't know) about three fundamentally different kinds of piÃ±onâ€“juniper vegetation. Persistent woodlands are found where local soils, climate, and disturbance regimes are favorable...