Viewing woody-plant encroachment through a social-ecological lens

Grasslands and savannas worldwide have been dramatically altered by woody-plant encroachment (WPE). Maintaining remnant grasslands and restoring degraded grasslands for the people and animals that depend on them will require a new paradigm for WPE, one that views WPE as a complex social-ecological system. Here, we examine WPE in this light, using a conceptual framework designed to bridge the biophysical and social domains. On the basis of this press-pulse WPE framework, we develop a set of integrative hypotheses and identify key knowledge gaps using the Southern Great Plains as a case study. An alternative-and potentially complementary-approach to the press-pulse WPE framework is that of classical dynamic systems modeling, which has been widely adopted in ecology and economics. The explicit coupling of the press-pulse WPE framework with dynamic systems modeling has the potential to yield new insights for understanding the local- to regional-scale processes that drive and constrain changes in grass-woody plant abundances and for predicting the socioeconomic and ecological consequences of these changes.