Tractor-trailer truckslin e up along a red and muddy earthen road. Large vinyl tarpaulins secured by ropes cover the open-topped hoppers of each one. Truck drivers hang out and prepare simple meals using stoves and kitchen utensils contained in a compact box built...

Many tropical rain forest regions are at risk of increased future drought. The net effects of drought on forest ecosystem functioning will be substantial if important ecological thresholds are passed. However, understanding and predicting these effects is challenging using observational studies alone. Field-based rainfall exclusion (canopy throughfall exclusion; TFE) experiments can offer mechanistic insight into the response to extended or severe drought and can be used to help improve model-based simulations, which are currently inadequate.