Evidence for climatic niche and biome shifts between native and novel ranges in plant species introduced to Australia

Abstract

Summary1. The potential invasive success of exotic plant species is thought to be associated with similarity in climate and biome between the original and novel range. We tested this assumption by quantifying the match between the realized climatic niches and biomes occupied in the exotic and native range of 26 plant species introduced to Australia. We then explored correlations between the propensity to shift climatic niche with residence time, invasion status, geographic range size, and species traits. 2. Occurrence data from the native and exotic range of 26 species introduced to Australia were obtained, and the overlap between native and exotic climate niches was calculated using betweenclass analysis. Shifts into novel biomes were assessed using a Geographic Information System (GIS). Correlations between introduction, distribution and species traits and the degree of climate matching were examined using nonparametric statistical tests. 3. Exotic species frequently occurred in climatic conditions outside those occupied in their native range (20 of 26 species). Nineteen species inhabited biomes in Australia not occupied in the native range and in some instances this shift represented the establishment of populations in novel biomes not present in the native range. No single-species trait, introduction or distributional characteristic was significantly associated with the degree of climatic niche shift. 4. Synthesis. Exotic species are able to occupy climate niches in the new range that differ substantially from those of the native range, and generally do not show biome conservatism between their native and introduced ranges. This implies that novel climatic conditions are not a major obstacle for exotic species establishing populations outside their native range. These results have important implications for the use and interpretation of ecological niche models used to predict the distribution of species in novel climates in time or space. The results also highlight the importance of alternate mechanisms, such as enemy release, phenotypic plasticity or rapid evolution, in the establishment of naturalized and invasive populations.

Reassessment of the invasion history of two species of Cakile (Brassicaceae) in Australia.

“…The Atlas of Living Australia (ALA), Australia's Virtual Herbarium (AVH) and The Global Biodiversity Information Facility (GBIF), for example, have made it tantalisingly easy to access distribution data for ecological analysis (e.g. Gallagher et al 2010;Aikio et al 2010). It must be appreciated, however, that these databases do not constitute primary data.…”

Available Climate Regimes Drive Niche Diversification during Range Expansion

“…Research on invasive species has documented numerous niche shifts after the invasion of new areas (e.g., Broennimann et al 2007;Gallagher et al 2010;Angetter et al 2011;Petersen 2012; but see Petitpierre et al 2012). We hypothesize that multiple long-distance dispersals between continents in the Danthonioideae could have led to repeated shifts in the climate niche, which could in turn have led to a pattern of punctuated niche evolution (Eldredge and Gould 1972).…”

Climate-induced range shifts of the American jackknife clam Ensis directus in Europe

“…The introduction of non-native species may also create opportunities for evolution. Some studies have pointed out a niche differentiation during the invasion process of some species (Broennimann et al 2007;Fitzpatrick et al 2007;Gallagher et al 2010;Medley 2010). However, other studies provided evidence that such results could be caused by methodological flaws (Menke et al 2009;Feeley and Silman 2011;Rödder et al 2009).…”