Do geographic distribution, niche property and life form explain plants' vulnerability to global change?

Abstract

International audienceWe modelled the future distribution in 2050 of 975 endemic plant species in southern Africa distributed among seven life forms, including new methodological insights improving the accuracy and ecological realism of predictions of global changes studies by: (i) using only endemic species as a way to capture the full realized niche of species, (ii) considering the direct impact of human pressure on landscape and biodiversity jointly with climate, and (iii) taking species' migration into account. Our analysis shows important promises for predicting the impacts of climate change in conjunction with land transformation. We have shown that the endemic flora of Southern Africa on average decreases with 41% in species richness among habitats and with 39% on species distribution range for the most optimistic scenario. We also compared the patterns of species' sensitivity with global change across life forms, using ecological and geographic characteristics of species. We demonstrate here that species and life form vulnerability to global changes can be partly explained according to species' (i) geographical distribution along climatic and biogeographic gradients, like climate anomalies, (ii) niche breadth or (iii) proximity to barrier preventing migration. Our results confirm that the sensitivity of a given species to global environmental changes depends upon its geographical distribution and ecological proprieties, and makes it possible to estimate a priori its potential sensitivity to these changes

Recent trends in the climate of Namaqualand, a megadiverse arid region of South Africa

“…12,13 Modelling studies have indicated that the Succulent Karoo may suffer a reduction in spatial extent of up to 40% as well as consequent reductions in the abundance and diversity of endemic species as a result of changes in temperature and rainfall. 14,15 In terms of individual species' responses to climate change, a study by Broennimann et al 16 found that geophytes and succulents, which make up over half of plant species in Namaqualand, were particularly vulnerable to climate change. They predicted a minimum decline in species richness of 41% for the Succulent Karoo biome.…”

Links between plant species’ spatial and temporal responses to a warming climate

“…As well as the level of climatic niche conservatism via phenological changes, this study focused on traits that can affect species' range shifts considered by other studies [32,33]: (i) dispersal abilities, (ii) niche breadth (reflecting ecological generalization) and (iii) perennation (reflecting generation time). Mean seed mass (mg) and seed releasing height (m), both measures of dispersal abilities, were derived from the LEDA Traitbase [34].…”

Local adaptation and the evolution of species’ ranges under climate change

“…A plethora of studies have used bioclimate envelope modelling to predict the 56 future biogeographic ranges of species (Bakkenes et al, 2002;Broennimann et al, 2006;Peterson et al, 2002;Schwarz et al, 2006;Thuiller et al, 2005). Refined 58 methods are being developed that entail the use of increasingly sophisticated statistics (e.g.…”