BES Annual Meeting 2024
Date:
Polycultures can better resist air and soil drought through functional traits
Extreme drought is threatening ecosystems worldwide. Biodiversity may provide ecosystems with some protection from extreme drought. Yet, observational and experimental studies disagree about how much and why biodiversity increases ecosystem resilience to drought. This difference may arise because drought simulation experiments (e.g. rain-out shelters) largely ignore ambient conditions (e.g. humidity). Here we use a mesocosm experiment in Ecotrons to manipulate both humidity and soil water content to disentangle the effects of air and soil drought on the functional traits of grassland plants in monoculture and polyculture. We found that species with different root trait niches can enhance the productivity of polycultures under both soil drought and air drought conditions. These findings suggest that under future drought scenarios biodiversity can enhance the resistance of communities to both above and belowground drought through complementary root trait combinations.