Drought-induced vegetation shifts in terrestrial ecosystems: The key role of regeneration dynamics

摘要: Ongoing climate change is modifying climatic conditions worldwide, with a trend towards drier in most regions. Vegetation will respond to these changes, eventually adjusting the new climate. It unclear, however, how close different ecosystems are climate-related tipping points and, thus, dramatic vegetation changes be short- mid-term, given existence of strong stabilizing processes. Here, we review published evidence for recent drought-induced shifts addressing following questions: (i) what necessary occur? (ii) How much do have at present and where they occurring? (iii) What main processes that favor/oppose occurrence ecological scales? (iv) complications detecting attributing shifts? (v) factors can interact drought promote or stability? We propose demographic framework classify likely outcome instances mortality, based upon survival adults potential replacement species regeneration both formerly dominant affected species. Out 35 selected case studies only eight were clearly consistent shift (species biome shift), whereas three corresponded self-replacements which affected, was able regenerate after suffering mortality. The other 24 cases classified as uncertain, either due lack information or, more commonly, because initially all showed similar levels mortality event. Overall, transitions drought-resistant replacing less resistant ones. However, almost half (44%) trajectories associated implied no functional type vegetation. Of those implying change, common one transition from tree- shrub-dominated communities. still limited. In this context, stress need improved, long-term monitoring programs sufficient temporal resolution. also highlight critical importance determining events, crucial role co-drivers, particularly management. Finally, illustrate placing biogeographical successional context may support progress our understanding underlying ecosystem-level implications.