Identifying sensitive ecosystems
Projected changes in climate in the 21st century are likely to have profound impacts on global ecosystems and it is essential to identify those regions that are most sensitive to these changes. In this study, the authors use a novel approach to characterise ecosystem responses to climate variability across global terrestrial systems. The new metric designed by the team is called the Vegetation Sensitivity Index (VSI) and measures the sensitivity of vegetation to air temperature, water availability and cloud cover.
Use of this new metric identified seven regions or ecosystems that show increased sensitivity to variability in climate: the arctic tundra, parts of the boreal forest (a vast ring of forest just below the arctic circle), tropical rainforest, alpine regions worldwide, steppe and prairie regions of central Asia and the Americas, the Caatinga deciduous forest in eastern South America, and eastern areas of Australia. The method also allowed the authors to quantify which aspects of the climate drive responses in different regions and to establish whether past climatic conditions affect present-day responses.
Implications for ecosystem resilience and human wellbeing
The environmental and anthropogenic changes of the 21st century are likely to increase the pressures on biodiversity and key ecosystem services, including carbon storage, water and nutrient cycling, flood defence, fuel, food, medicine, building materials and textiles. The ability for vegetation to tolerate climate variability is one key component that we need to understand if we are to prioritise areas that can keep providing ecosystem services in the future.
This work provides the first step towards addressing why some regions seem to be more sensitive than others and therefore to assessing the impacts on the resilience of ecosystems and human wellbeing in the face of increased climate variability.
The full paper is available online through the Nature website:
Seddon, A.W.R., Macias-Fauria, M., Long, P.R., Benz, D. & Willis*, K.J.W. (2016). Sensitivity of global terrestrial ecosystems to climate variability. Nature. DOI: 10.1038/nature16986. Available online