Delayed response to climate change could leave some species isolated in climatic traps
By Summit Voice
SUMMIT COUNTY — A new study of Alpine plants by Austrian ecologists suggests that some current climate models may over-estimate the rate of habitat loss resulting from global warming in the next few decades.
But the long-term impact is still likely to be the loss of many species that live in narrow ecological niches that will mostly be lost as the climate continues to warm. There may be a delayed response in some species that will be able to hang on in tiny microclimates as the ecosystems around them change, but they to will be lost due to an inability to disperse across any significant distance, according to ecologists from the Department of Conservation Biology, Vegetation and Landscape Ecology of the University of Vienna.
The results of the study, published in Nature Climate Change, suggest that, by the end of the 21st century, high Alpine mountain flora will lose on average 44 percent to 50 percent of its current distribution area, a moderate forecast as compared to predictions based on traditional modeling techniques.
Plant species are expected to respond to a warming climate by moving their ranges pole-wards or up-wards in mountains. Previous attempts to predict such range shifts have made several simplifying assumptions leading to large uncertainties about the impending loss of mountain plant populations.
“These results warn against drawing over-optimistic conclusions from the relatively modest loss of mountain plant populations likely to be observed during the coming decades”, said Stefan Dullinger from the University of Vienna. “Because the final consequences of climate warming on plant distribution in the Alps will only become realized with a delay of decades or even centuries.”
In addition, the researchers found that plants endemic to the European Alps are particularly sensitive to climate impacts. Up to 75 percent of these species might face a reduction of their ranges by more than 80 percent of their current distribution because they often have particularly low dispersal capacities and occur in lower marginal mountain chains, leaving them in isolated “climatic traps.
“This is particularly worrisome because endemic plants represent a natural heritage unique to a region and their loss is hence irreversible”, said Karl Hülber from the Vienna Institute of Nature Conservation & Analyses.