Water thresholds in the Cerrado

Several ecosystems worldwide are subjected to droughts with a certain frequency, and drought stress is a major driver of ecosystem functioning decreases, productivity losses, and disruptions in the carbon balance. Global climate change might aggravate issues related to drought stress, since more frequent and extreme droughts are expected in the future due to changes in the climate, and we still lack knowledge on many aspects of plants and ecosystems response to drought. For instance, much is still unknown about ecosystem-level thresholds in water content that can lead to decreased vegetation productivity (and potentially, plants mortality) and to a higher risk of burning. Thus, with this research, we aim at answering what are the thresholds in the system water content that lead to a decrease in ecosystem’s productivity and/or leaf area, and an increased flammability risk. Remote sensing estimates of ecosystems’ relative water content (RWC) will be validated and used to assess the ecosystem-scale critical thresholds in several vegetation types in central Brazil (the Cerrado). These thresholds might indicate when an ecosystem is approaching a point in which its productivity will critically decrease, and potentially, an increased risk of plants mortality. Researcher: Paulo Bernardino