Global field observations of tree die-off reveal hotter-drought fingerprint for Earth’s forests

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: April 5, 2022

Abstract Earth’s forests face grave challenges in the Anthropocene, including hotter droughts increasingly associated with widespread forest die-off events. But despite vital importance of to global ecosystem services, their fates a warming world remain highly uncertain. Lacking is quantitative determination commonality climate anomalies pulses tree mortality—from published, field-documented mortality events—required for understanding role extreme events overall patterns. Here we established geo-referenced database documenting climate-induced spanning all tree-supporting biomes and continents, from 154 peer-reviewed studies since 1970. Our analysis quantifies “hotter-drought fingerprint” these tree-mortality sites—effectively drier signal mortality—across 675 locations encompassing 1,303 plots. Frequency observed mortality-year conditions strongly increases nonlinearly under projected warming. also provides initial footing further community-developed, quantitative, ground-based monitoring mortality.

Language: Английский

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Impact of 2019–2020 mega-fires on Australian fauna habitat

Nature Ecology & Evolution, Journal Year: 2020, Volume and Issue: 4(10), P. 1321 - 1326

Published: July 20, 2020

Language: Английский

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Increased likelihood of heat-induced large wildfires in the Mediterranean Basin

Scientific Reports, Journal Year: 2020, Volume and Issue: 10(1)

Published: Aug. 14, 2020

Abstract Wildfire activity is expected to increase across the Mediterranean Basin because of climate change. However, effects future change on combinations atmospheric conditions that promote wildfire remain largely unknown. Using a fire-weather based classification wildfires, we show scenarios point an in frequency two heat-induced types have been related largest wildfires recent years. Heat-induced are characterized by compound dry and warm occurring during summer heatwaves, either under moderate ( heatwave type) or intense hot drought drought. The projected 14% end century (2071–2100) RCP4.5 scenario, 30% RCP8.5, suggesting extent large will throughout Basin.

Language: Английский

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Watersheds may not recover from drought

Science, Journal Year: 2021, Volume and Issue: 372(6543), P. 745 - 749

Published: May 13, 2021

The Millennium Drought (southeastern Australia) provided a natural experiment to challenge the assumption that watershed streamflow always recovers from drought. Seven years after drought, runoff (as fraction of precipitation) had not recovered in 37% watersheds, and number watersheds was increasing. When recovery did occur, it explained by wetness. For those recovered, ~80% showed no evidence recovering soon, suggesting persistence within low-runoff state. post-drought precipitation going found be likely increased evapotranspiration per unit precipitation. These findings show can have finite resilience disturbances suggest hydrological droughts persist indefinitely meteorological droughts.

Language: Английский

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Extreme heat increases stomatal conductance and drought‐induced mortality risk in vulnerable plant species

Global Change Biology, Journal Year: 2021, Volume and Issue: 28(3), P. 1133 - 1146

Published: Nov. 6, 2021

Tree mortality during global-change-type drought is usually attributed to xylem dysfunction, but as climate change increases the frequency of extreme heat events, it necessary better understand interactive role stress. We hypothesized that some drought-stressed plants paradoxically open stomata in heatwaves prevent leaves from critically overheating. experimentally imposed (>40°C) and stress onto 20 broadleaf evergreen tree/shrub species a glasshouse study. Most well-watered avoided lethal overheating, exacerbated thermal damage heatwaves. Thermal safety margins (TSM) quantifying difference between leaf surface temperature critical temperature, where photosynthesis disrupted, identified vulnerability Several mechanisms contributed high tolerance avoidance damaging temperatures-small size, low osmotic potential, mass per area (i.e., thick, dense leaves), transpirational capacity, access water. Water-stressed had smaller TSM, greater crown dieback, fundamentally different stomatal heatwave response relative plants. On average, closed decreased conductance (gs ) heatwave, droughted did not. Plant with gs , either due isohydric behavior under water deficit or inherently opened increased temperatures. The current paradigm maintains close before hydraulic thresholds are surpassed, our results suggest may dramatically increase (over sixfold increases) even past their turgor loss point. By actively increasing at temperatures, can be driven toward more rapidly than has been previously recognized. inclusion TSM responses could improve ability predict tree future droughts.

Language: Английский

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Widespread shift from ecosystem energy to water limitation with climate change

Nature Climate Change, Journal Year: 2022, Volume and Issue: 12(7), P. 677 - 684

Published: July 1, 2022

Abstract Terrestrial ecosystems are essential for food and water security CO 2 uptake. Ecosystem function is dependent on the availability of soil moisture, yet it unclear how climate change will alter moisture limitation vegetation. Here we use an ecosystem index that distinguishes energy limitations in Earth system model simulations to show a widespread regime shift from between 1980 2100. This found both space time. While this mainly related reduction energy-limited regions associated with increasing incoming shortwave radiation, largest towards where radiation increases accompanied by decreases. We therefore demonstrate stronger than implied individual trends terrestrial evaporation, important implications future services.

Language: Английский

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Drought legacies and ecosystem responses to subsequent drought

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(17), P. 5086 - 5103

Published: May 24, 2022

Climate change is expected to increase the frequency and severity of droughts. These events, which can cause significant perturbations terrestrial ecosystems potentially long-term impacts on ecosystem structure functioning after drought has subsided are often called 'drought legacies'. While immediate effects have been comparatively well characterized, our broader understanding legacies just emerging. Drought relate all aspects functioning, involving changes at species community scale as alterations soil properties. This consequences for responses subsequent drought. Here, we synthesize current knowledge underlying mechanisms. We highlight relevance legacy duration different processes using examples carbon cycling composition. present hypotheses characterizing how intrinsic (i.e. biotic abiotic properties processes) extrinsic timing, severity, frequency) factors could alter resilience trajectories under scenarios recurrent events. propose ways improving their implications needed assess longer-term droughts functioning.

Language: Английский

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Post-disturbance reorganization of forest ecosystems in a changing world

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(28)

Published: July 5, 2022

Forest ecosystems are strongly impacted by continuing climate change and increasing disturbance activity, but how forest dynamics will respond remains highly uncertain. Here, we argue that a short time window after (i.e., discrete event disrupts prevailing ecosystem structure composition releases resources) is pivotal for future development. Trees establish during this reorganization phase can shape centuries, providing operational early indications of change. While has been fruitfully studied through lens resilience, profound ecological changes be masked resilience versus regime shift dichotomy. We present framework characterizing the full spectrum disturbance, analyzing along dimensions (number, size, spatial arrangement trees) (identity diversity tree species). propose four major pathways which cover persist reorganize following disturbance: (no in composition), restructuring (structure does not), reassembly (composition replacement both change). Regime shifts occur when vegetation altered so profoundly emerging trajectory leads to nonforest. identify fundamental processes underpinning which, if disrupted, deflect away from resilience. To understand predict reorganization, assessing these traits modulating them crucial. A new wave experiments, measurements, models emphasizing further capacity anticipate dynamics.

Language: Английский

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Global drought trends and future projections

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences, Journal Year: 2022, Volume and Issue: 380(2238)

Published: Oct. 23, 2022

Drought is one of the most difficult natural hazards to quantify and divided into categories (meteorological, agricultural, ecological hydrological), which makes assessing recent changes future scenarios extremely difficult. This opinion piece includes a review scientific literature on topic analyses trends in meteorological droughts by using long-term precipitation records different drought metrics evaluate role global warming processes hydrological severity over last four decades, during sharp increase atmospheric evaporative demand (AED) has been recorded. Meteorological do not show any substantial at scale least 120 years, but an agricultural seems emerge as consequence AED. Lastly, this study evaluates projections from earth system models focuses important aspects that need be considered when evaluating changing climate, such use uncertainty modelling approaches. article part Royal Society Science+ meeting issue ‘Drought risk Anthropocene’.

Language: Английский

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No projected global drylands expansion under greenhouse warming

Nature Climate Change, Journal Year: 2021, Volume and Issue: 11(4), P. 331 - 337

Published: March 11, 2021

Language: Английский

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