Quantifying the invasiveness of species

Abstract

The success of invasive species has been explained by two contrasting but non-exclusive views: (i) intrinsic factors make some species inherently good invaders; (ii) species become invasive as a result of extrinsic ecological and genetic influences such as release from natural enemies, hybridization or other novel ecological and evolutionary interactions. These viewpoints are rarely distinguished but hinge on distinct mechanisms leading to different management scenarios. To improve tests of these hypotheses of invasion success we introduce a simple mathematical framework to quantify the invasiveness of species along two axes: (i) interspecific differences in performance among native and introduced species within a region, and (ii) intraspecific differences between populations of a species in its native and introduced ranges. Applying these equations to a sample dataset of occurrences of 1,416 plant species across Europe, Argentina, and South Africa, we found that many species are common in their native range but become rare following introduction; only a few introduced species become more common. Biogeographical factors limiting spread (e.g. biotic resistance, time of invasion) therefore appear more common than those promoting invasion (e.g. enemy release). Invasiveness, as measured by occurrence data, is better explained by inter-specific variation in invasion potential than biogeographical changes in performance. We discuss how applying these Colautti et al. / NeoBiota 21: 7-27 (2014) 8 comparisons to more detailed performance data would improve hypothesis testing in invasion biology and potentially lead to more efficient management strategies.

Heterogeneity in patterns of survival of the invasive species Ipomoea carnea in urban habitats along the Egyptian Nile Delta

“…Yet, the relative importance of particular life history and functional traits for invasion success and impact is strongly context-dependent and likely to change across environments (Dawson et al 2009). In cases of significant impact by invasive plants, estimating 'invasiveness' using plant traits that predict plant survival could be used to determine invasion resistance of native plant communities (Ortega and Pearson 2005, Radosevich et al 2007, Colautti et al 2014.This is particularly important to understand in urban habitats where urbanization can favor non-native species (McKinney 2006). Urbanization reduces the competitiveness of established vegetation (Wilson and Tilman 1995) and increases the availability of resources (Johnstone 1986, McConnaughay andBazzaz 1991), which can be exploited by non-native species, further influencing their invasiveness.…”

Seven years of NeoBiota – the times, were they a changin’?

“…Bridging the two aforementioned topics is the study of Colautti et al (2014). They used hypotheses in invasion biology and improved tests of these by introducing a simple mathematical framework to quantify the invasiveness of species.…”

The Global Garlic Mustard Field Survey (GGMFS): challenges and opportunities of a unique, large-scale collaboration for invasion biology

“…Moreover, the species that both perform well in their native range and expand their niche in invaded regions should be the most successful invaders. However, few studies have measured performance of natural populations to directly test the assumption of increased vigour and these have been limited in size and geographical scope Parker et al 2013;Colautti et al 2014). Indeed, even basic field performance comparisons between native and introduced populations are often not available for many of the world's most notorious invasive species, and where available, there is often little information about variation in performance among individuals or populations within each range (Parker et al 2013).…”

“…Since investigation into this topic was launched over a half-century ago (Elton 1958;Baker and Stebbins 1965), research on this question has expanded rapidly, leading to a large and growing number of ecological and evolutionary hypotheses (Sakai et al 2001;Facon et al 2006;Catford et al 2009;Gurevitch et al 2011;Jeschke et al 2012). Biological hypotheses of invasion success generally fall into one of two categories: (i) biogeographical differences between native and introduced ranges and (ii) functional traits that differ between species or higher-order phylogenetic groups (Colautti et al 2014). Hypotheses in the first category attribute the success of invasive species to biological differences between native and introduced regions that are more favourable in the latter.…”