Emergent insights from the synthesis of conceptual frameworks for biological invasions

Abstract

A general understanding of biological invasions will provide insights into fundamental ecological and evolutionary problems and contribute to more efficient and effective prediction, prevention and control of invasions. We review recent papers that have proposed conceptual frameworks for invasion biology. These papers offer important advances and signal a maturation of the field, but a broad synthesis is still lacking. Conceptual frameworks for invasion do not require invocation of unique concepts, but rather should reflect the unifying principles of ecology and evolutionary biology. A conceptual framework should incorporate multicausality, include interactions between causal factors and account for lags between various stages. We emphasize the centrality of demography in invasions, and distinguish between explaining three of the most important characteristics by which we recognize invasions: rapid local population increase, monocultures or community dominance, and range expansion. As a contribution towards developing a conceptual synthesis of invasions based on these criteria, we outline a framework that explicitly incorporates consideration of the fundamental ecological and evolutionary processes involved. The development of a more inclusive and mechanistic conceptual framework for invasion should facilitate quantitative and testable evaluation of causal factors, and can potentially lead to a better understanding of the biology of invasions.

Conceptual Frameworks and Methods for Advancing Invasion Ecology

“…Some recent studies offer ideas for a synthesis of invasion theory (Colautti and MacIsaac 2004;Blumenthal 2006;Catford et al 2009;Davis 2009;Gurevitch et al 2011). These approaches each put together different pieces of available knowledge in a specific and valuable way, but each approach is limited in what it covers.…”

Climate Dynamics, Invader Fitness, and Ecosystem Resistance in an Invasion-Factor Framework

“…Some of the more recent conceptual models depicting invasions have broadly synthesized concepts and theory to test hypotheses, improved understanding, and identified research directions (Catford et al 2009;Gurevitch et al 2011;Kueffer et al 2013) or have taken a reductionist approach by focusing on fluctuating resource availability (Davis et al 2000), the invader and biotic resistance (Facon et al 2006), introduced and native ranges (van Kleunen et al 2010), and current and future climate conditions (Ibáñez et al 2014). Our approach builds on several of these frameworks (e.g., Catford et al 2009;Gurevitch et al 2011;Perkins et al 2011), as we take existing knowledge from published empirical studies and portray it graphically to show what is known and unknown about a component in the invasion process for any particular plant species.…”

“…Others have used traits (Alpert et al 2000), conditions (Bradley et al 2010), or a combination (Diez et al 2012) as a base for their predictions about plant invasions. Gurevitch et al (2011) describe the invasion process, which begins after an introduction event has occurred, as rapid population increase, established local dominance, and rapid range expansion. These three components characterize invasions and often overlap in occurrence.…”

“…Our approach builds on frameworks developed by Catford et al (2009), Gurevitch et al (2011), and Perkins et al (2011 by taking existing knowledge from published empirical research and portraying it graphically to show what is known and unknown about a component in the invasion process for any particular plant species. By creating a framework that provides a visual snapshot of a target invasive plant based on empirical studies, we provide a guide that can be used to (1) establish research priorities and (2) identify components in the invasion process that can be targeted for successful management.…”

“…We provide a simultaneous conceptualization of the influence of climate dynamics, ecosystem resistance, and invader fitness (our intrinsic invader characteristic factor) on each component of the invasion process, which is the main difference between our approach and others (Table 1; Figure 1). With regard to climate, it is incorporated into "abiotic characteristics" in Catford et al (2009), "environmental conditions" in Perkins et al (2011), and "ecosystem processes" in Gurevitch et al (2011), but these are much wider applications than our climate dynamics factor (Table 1). "System context" in Foxcroft et al (2011) is an even broader category, incorporating propagule pressure and vector efficiency, as well as global climate change.…”