Compound droughts and hot extremes: Characteristics, drivers, changes, and impacts

Earth-Science Reviews, Journal Year: 2022, Volume and Issue: 235, P. 104241 - 104241

Published: Nov. 8, 2022

Language: Английский

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Exceptional heat and atmospheric dryness amplified losses of primary production during the 2020 U.S. Southwest hot drought

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(16), P. 4794 - 4806

Published: April 22, 2022

Earth's ecosystems are increasingly threatened by "hot drought," which occurs when hot air temperatures coincide with precipitation deficits, intensifying the hydrological, physiological, and ecological effects of drought enhancing evaporative losses soil moisture (SM) increasing plant stress due to higher vapor pressure deficit (VPD). Drought-induced reductions in gross primary production (GPP) exert a major influence on terrestrial carbon sink, but extent hotter atmospherically drier conditions will amplify deficits cycle remains largely unknown. During summer autumn 2020, U.S. Southwest experienced one most intense droughts record, record-low record-high temperature VPD across region. Here, we use this natural experiment evaluate GPP further decompose those negative anomalies into their constituent meteorological hydrological drivers. We found 122 Tg C (>25%) reduction below 2015-2019 mean, far lowest regional over Soil Moisture Active Passive satellite record. Roughly half estimated loss was attributable low SM (likely combination warming-enhanced depletion), record-breaking amplified GPP, contributing roughly 40% anomaly. Both very likely continue next century, leading more frequent substantially drought-induced reductions.

Language: Английский

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The impacts of rising vapour pressure deficit in natural and managed ecosystems

Plant Cell & Environment, Journal Year: 2024, Volume and Issue: 47(9), P. 3561 - 3589

Published: Feb. 13, 2024

An exponential rise in the atmospheric vapour pressure deficit (VPD) is among most consequential impacts of climate change terrestrial ecosystems. Rising VPD has negative and cascading effects on nearly all aspects plant function including photosynthesis, water status, growth survival. These responses are exacerbated by land-atmosphere interactions that couple to soil govern evolution drought, affecting a range ecosystem services carbon uptake, biodiversity, provisioning resources crop yields. However, despite global nature this phenomenon, research how incorporate these into resilient management regimes largely its infancy, due part entanglement trends with those other co-evolving drivers. Here, we review mechanistic bases at spatial scales, paying particular attention independent interactive influence context environmental changes. We then evaluate consequences within key contexts, resources, croplands, wildfire risk mitigation natural grasslands forests. conclude recommendations describing could be altered mitigate otherwise highly deleterious rising VPD.

Language: Английский

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Dynamics of global dryland vegetation were more sensitive to soil moisture: Evidence from multiple vegetation indices

Agricultural and Forest Meteorology, Journal Year: 2023, Volume and Issue: 331, P. 109327 - 109327

Published: Jan. 20, 2023

Language: Английский

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Contrasting impact of extreme soil and atmospheric dryness on the functioning of trees and forests

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 916, P. 169931 - 169931

Published: Jan. 8, 2024

Recent studies indicate an increase in the frequency of extreme compound dryness days (days with both soil AND air dryness) across central Europe future, little information on their impact functioning trees and forests. This study aims to quantify assess dryness, For this, >15 years ecosystem-level (carbon dioxide water vapor fluxes) 6-10 tree-level measurements (transpiration growth) each from a montane mixed deciduous forest (CH-Lae) subalpine evergreen coniferous (CH-Dav) Switzerland, is used. The results showed limitation CO

Language: Английский

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Serious underestimation of reduced carbon uptake due to vegetation compound droughts

npj Climate and Atmospheric Science, Journal Year: 2024, Volume and Issue: 7(1)

Published: Jan. 19, 2024

Abstract Compound droughts with low soil moisture (SM) and high vapor pressure deficit (VPD) pose significant threats to terrestrial carbon sink agricultural production. However, the frequency intensity of compound their adverse impacts on cycle remain highly uncertain. Here, we define identify vegetation (VCDs) when SM VPD severely limit adversely affect uptake. We find frequent severe VCDs considerable uptake in mid- low-latitude regions, particularly drylands. Risks have been greatly underestimated as widely adopted quantile-based approach identifies only 11% 26% global GPP anomalies due VCDs. The are projected increase further, irrespective whether CO 2 fertilization effect growth photosynthesis is considered or not. These findings improve our understanding current future risks underline importance adaptation measures cope ever-increasing droughts.

Language: Английский

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Long‐term changes in forest response to extreme atmospheric dryness

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(18), P. 5379 - 5396

Published: June 28, 2023

Abstract Atmospheric dryness, as indicated by vapor pressure deficit (VPD), has a strong influence on forest greenhouse gas exchange with the atmosphere. In this study, we used long‐term (10–30 years) net ecosystem productivity (NEP) measurements from 60 sites across world (1003 site‐years) to quantify changes in NEP resistance and recovery response extreme atmospheric dryness. We tested two hypotheses: first, differences of forests will depend both biophysical characteristics (i.e., leaf area index [LAI] type) well local meteorological conditions site mean VPD site), second, experiencing an increasing trend frequency intensity dryness show over time due emergence ecological stress memory. data‐driven statistical learning approach multiple years. Our results showed that types, LAI, median explained 50% variance recovery, drier showing higher compared less The impact events lasted for up 3 days following most severe forests, than 100%. rejected our second hypothesis found no consistent relationship between trends different sites, thus increase it is predicted might not or terms NEP.

Language: Английский

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Unprecedented decline in photosynthesis caused by summer 2022 record-breaking compound drought-heatwave over Yangtze River Basin

Science Bulletin, Journal Year: 2023, Volume and Issue: 68(19), P. 2160 - 2163

Published: Aug. 7, 2023

Language: Английский

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Satellite solar‐induced chlorophyll fluorescence tracks physiological drought stress development during 2020 southwest US drought

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(12), P. 3395 - 3408

Published: March 17, 2023

Monitoring and estimating drought impact on plant physiological processes over large regions remains a major challenge for remote sensing land surface modeling, with important implications understanding mortality mechanisms predicting the climate change terrestrial carbon water cycles. The Orbiting Carbon Observatory 3 (OCO-3), its unique diurnal observing capability, offers new opportunity to track stress physiology. Using radiative transfer machine learning we derive metric of afternoon photosynthetic depression from OCO-3 solar-induced chlorophyll fluorescence (SIF) as an indicator stress. This signal enables spatially explicit mapping plants' response drought. observations, detect widespread increasing during 2020 southwest US Although is largely related vapor pressure deficit (VPD), our results suggest that sensitivity VPD increases intensifies develops differently shrublands grasslands. Our findings highlight potential using satellite SIF observations advance mechanistic ecosystems improve modeling.

Language: Английский

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Field experiments have enhanced our understanding of drought impacts on terrestrial ecosystems—But where do we go from here?

Functional Ecology, Journal Year: 2023, Volume and Issue: 38(1), P. 76 - 97

Published: Oct. 31, 2023

Abstract We review results from field experiments that simulate drought, an ecologically impactful global change threat is predicted to increase in magnitude, extent, duration and frequency. Our goal address, primarily ecosystem perspective, the questions ‘What have we learned drought experiments?’ ‘Where do go here?’. Drought are among most numerous climate manipulations been deployed across a wide range of biomes, although conducted short‐statured, water‐limited ecosystems. Collectively, these enabled ecologists quantify negative responses occur for aspects structure function. Multiple meta‐analyses also comparisons relative effect sizes hundreds sites, particularly carbon cycle metrics. Overall, provided strong evidence sensitivity increases with aridity, but plant traits associated aridity not necessarily predictive resistance. There intriguing as magnitude or extreme levels, strategies may shift tolerance escape/avoidance. highlight three areas where more needed advance our understanding. First, because intensifying multiple ways, address alterations versus duration, timing and/or frequency (individually interactively). Second, drivers be shifting—from precipitation deficits rising atmospheric demand water—and disentangling how ecosystems respond changes hydrological ‘supply demand’ critical understanding impacts future. Finally, attention should focussed on post‐drought recovery periods since legacies can affect functioning much longer than itself. conclude call fundamental focus those designed ‘response experiments’, quantifying function, ‘mechanistic experiments’—those explicitly manipulate ecological processes attributes thought underpin responses. Read free Plain Language Summary this article Journal blog.

Language: Английский

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