Impact: Toward a Framework for Understanding the Ecological Effects of Invaders

摘要: Although ecologists commonly talk about the impacts of nonindigenous species, little formal attention has been given to defining what we mean by impact, or connecting ecological theory with particular measures impact. The resulting lack generalizations regarding invasion is more than an academic problem; need be able distinguish invaders minor effects from those large in order prioritize management efforts. This paper focuses on defining, evaluating, and comparing a variety impact drawn empirical examples theoretical reasoning. We begin arguing that total invader includes three fundamental dimensions: range, abundance, per-capita per-biomass effect invader. Then summarize previous approaches measuring at different organizational levels, suggest some new approaches. Reviewing mathematical models argue studies using community assembly could act as basis for better monitoring programs, well provide clearer understanding relationship among types then discuss challenges come invasive species policy context. end recommendations how field biology might proceed build general framework predicting impacts. In particular, advocate designed explore correlations measures: Are results complex multivariate methods adequately captured simple composite metrics such richness? How are native populations correlated ecosystem functions? there useful bioindicators impacts? To extent does depend system which it measured? Three would insights this line inquiry: (1) measure multiple scales levels organization, (2) synthesize currently available data response variables, (3) guide work generalities.