Abstract ID: 3.12636 | Not reviewed | Requested as: Talk | TBA | TBA

Mountains are experiencing climate warming at a faster pace than other terrestrial ecosystems, with temperature increases of up to twice the global average. These rapid changes, combined with shifts in precipitation patterns and increased nitrogen deposition, make mountain ecosystems particularly vulnerable and critical as early warning systems for vegetation responses to global change. To strengthen our mechanistic understanding of how environmental drivers affect mountain vegetation and associated ecosystem processes, we systematically reviewed three decades of manipulation experiments. Among the seven major global change drivers examined (temperature, water availability, nutrient addition, snow manipulation, radiation, atmospheric gases, and disturbance), temperature was most frequently manipulated (45% of studies), followed by nutrient addition (15%) and water availability (14%). Our analysis of 767 studies reveals that temperature manipulation consistently affected plant life history, functional traits, and phenology, with experimental warming generally accelerating phenological events and altering species composition. The review showed strong evidence that changes in water and nutrient availability directly impact plant life history and ecosystem functioning. Water limitation has particularly severe effects on plant production, leading to annual yield losses of up to 40%. We found that soil microbial communities respond rapidly to warming, with implications for nutrient cycling and decomposition processes. Long-term datasets demonstrate complex interactions between climate warming and soil processes, where changes in plant functional traits and community composition influence carbon and nutrient cycling. Notably, experiments combining temperature with water manipulation showed that soil moisture often mediates warming effects on plant productivity and biogeochemical cycles. While biotic interactions were understudied (only 2% of responses), evidence suggests that warming can disrupt plant-pollinator relationships and alter competitive dynamics between species. Despite these important findings, there are several gaps that require urgent attention. A broader approach that integrates experimental data with field observations and relies on international collaboration through coordinated experiments could help address these gaps and provide a more consistent and robust picture of the impacts of global change on mountain ecosystems.