Mon, Aug 02, 2021:On Demand
Background/Question/Methods
Drought can act over seasons to decades and beyond, with notable examples in tropical forests evident in the recent past, as well as in a range of possible futures this century. However, studying drought responses by trees and forests over ecologically meaningful timescales is challenging. This is especially true at stand scale, where both inter- and intra-specific variations in growth, drought-induced tree mortality rates and acclimation among different plant physiological traits can all influence long-term biogeochemical and ecological trajectories, with large potential global impact. As part of our attempts to address this challenge, we synthesise recent findings from the world’s only multi-decadal (20 yrs) and stand-scale (1 ha treatment) throughfall exclusion experiment in tropical forest, situated in eastern Amazonia.
Results/Conclusions
We quantify and analyse: (i) how different physiological traits (metabolic, hydraulic) exert control upon growth and how this changes during drought; (ii) how traits differ in their capacity to acclimate under long-term drought stress, and how taxonomic identity and tree size influence these processes; (iii) how new high-resolution laser-based structural analysis is transforming our quantification of metabolic, structural and growth responses to drought; and (iv) how drought alters overall water use and water stress at individual tree and stand-scale, over different timescales. The results connect a series of new findings that inform short- and long-term influences of future drought on tropical forest structure, function and composition. They also highlight the importance of accounting for diversity across physiological trait responses and species identity.
Drought can act over seasons to decades and beyond, with notable examples in tropical forests evident in the recent past, as well as in a range of possible futures this century. However, studying drought responses by trees and forests over ecologically meaningful timescales is challenging. This is especially true at stand scale, where both inter- and intra-specific variations in growth, drought-induced tree mortality rates and acclimation among different plant physiological traits can all influence long-term biogeochemical and ecological trajectories, with large potential global impact. As part of our attempts to address this challenge, we synthesise recent findings from the world’s only multi-decadal (20 yrs) and stand-scale (1 ha treatment) throughfall exclusion experiment in tropical forest, situated in eastern Amazonia.
Results/Conclusions
We quantify and analyse: (i) how different physiological traits (metabolic, hydraulic) exert control upon growth and how this changes during drought; (ii) how traits differ in their capacity to acclimate under long-term drought stress, and how taxonomic identity and tree size influence these processes; (iii) how new high-resolution laser-based structural analysis is transforming our quantification of metabolic, structural and growth responses to drought; and (iv) how drought alters overall water use and water stress at individual tree and stand-scale, over different timescales. The results connect a series of new findings that inform short- and long-term influences of future drought on tropical forest structure, function and composition. They also highlight the importance of accounting for diversity across physiological trait responses and species identity.