Biodiversity lowers ecosystem sensitivity to climate variability

The sensitivity of vegetation productivity to climate variability is a key component of ecosystem resilience. Ground-based observations and experimental manipulations often find biodiversity lowers ecosystem sensitivity to climate variability. Whether these plot-level effects scale up to entire regions and continents remains unknown. We compared temporal changes in vegetation productivity (EVI) with that of temperature and precipitation across the New World over the past 20 years. We explored ecosystem sensitivity implying vegetation response characteristics to short-term (month-to-month) and mid-to-long-term (year-to-year) temperature and rainfall oscillations. Next, we tested whether these patterns coincide with areas of elevated plant biodiversity across multiple dimensions (richness, PD and FD). Biodiversity lowered ecosystem sensitivity to temperature strongly in energy limited-regions, while reducing ecosystem sensitivity to precipitation strongly in water-limited regions. At the interannual scale, biodiversity dimensions lowered sensitivity to both temperature and precipitation. However, at the seasonal scale, biodiversity lowered ecosystem sensitivity to seasonality in temperature, while increasing sensitivity to seasonality in precipitation. Biodiversity may stabilize ecosystems to climate seasonality via asynchrony or greater diversity of slow-growth species able to hold biomass (e.g., via low leaf turnover) despite seasonal changes in temperature. In contrast, an increased ecosystem sensitivity to seasonality in precipitation may result from more fast-growing plant species, increasing vegetation responsiveness to erratic resources availability (e.g., water and nutrients) shortly after rainfalls, thus elevating rates of ecosystem recovery from disturbance. In summary, we found support for a mediating effect of biodiversity on temporal variability vegetation productivity, and probably productivity-dependent ecosystem services. That regions of high biodiversity coincide with those of low ecosystem sensitivity suggests biodiversity may be a powerful contributor to stabilizing ecosystem responses to under changing climate.