Tropical tree growth driven by dry-season climate variability

Nature Geoscience, Journal Year: 2022, Volume and Issue: 15(4), P. 269 - 276

Published: March 31, 2022

Language: Английский

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Global variations in critical drought thresholds that impact vegetation

National Science Review, Journal Year: 2023, Volume and Issue: 10(5)

Published: Feb. 24, 2023

Identifying the thresholds of drought that, if crossed, suppress vegetation functioning is vital for accurate quantification how land ecosystems respond to climate variability and change. We present a globally applicable framework identify responses different levels known soil-moisture deficits using four remotely sensed proxies spanning 2001-2018. The identified represent critical inflection points changing from highly resistant vulnerable in response stress, as warning signal substantial impacts. Drought varied geographically, with much lower percentiles anomalies vegetated areas covered by more forests, corresponding comparably stronger capacity mitigate soil water deficit stress forested ecosystems. Generally, those are detected humid climates. State-of-the-art models, however, overestimated moisture (i.e. overestimating impacts), especially higher forest covers arid few covers. Based on model projections, we predict that risk damage will increase end twenty-first century some hotspots like East Asia, Europe, Amazon, southern Australia eastern Africa. Our data-based results inform projections future impacts terrestrial provide an effective tool management.

Language: Английский

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Mutually inclusive mechanisms of drought‐induced tree mortality

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(10), P. 3365 - 3378

Published: March 5, 2022

Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced mortality. Although numerous physiological risk factors have been identified, importance two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how local neighborhood composition affects individual mortality risk. We studied 9435 young trees 12 temperate species planted in diversity experiment 2013 to assess traits, dynamics, pest infestation, height competition influence Following most extreme since record 2018, one third these died. Across species, safety margins (HSMs) were negatively shift towards higher sugar fraction non-structural carbohydrate (NSC) pool positively associated with Moreover, infested bark beetles had risk, taller lower Most interactions beneficial, although effects highly species-specific. Species that suffered more from drought, especially Larix spp. Betula spp., tended increase survival probability their neighbors vice versa. While severe tissue dehydration marks final stage mortality, we show interrelated series other, mutually inclusive processes. These include shifts NSC pools driven osmotic adjustment and/or starch depletion as well infestation are modulated size identity its neighbors. A holistic view accounts multiple causes required improve predictions trends forest dynamics identify beneficial combinations.

Language: Английский

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European beech dieback after premature leaf senescence during the 2018 drought in northern Switzerland

Plant Biology, Journal Year: 2022, Volume and Issue: 24(7), P. 1132 - 1145

Published: Sept. 14, 2022

During the particularly severe hot summer drought in 2018, widespread premature leaf senescence was observed several broadleaved tree species Central Europe, European beech (Fagus sylvatica L.). For beech, it is yet unknown whether evoked a decline towards mortality or trees can recover longer term. In this study, we monitored crown dieback, and secondary damage symptoms 963 initially live that exhibited either normal 2018 three regions northern Switzerland from to 2021. We related multiple climate- stand-related parameters. Cumulative continuously increased up 7.2% 1.3% 2021 for with respectively. Mean dieback surviving peaked at 29.2% 2020 8.1% 2019 senescence, Thereafter, showed first signs of recovery. Crown more pronounced recovery slower growing on drier sites, larger trees. The presence bleeding cankers 24.6% 10.7% bark beetle holes 22.8% 14.8% Both occurred frequently had higher proportions and/or 2018. Our findings demonstrate context-specific differences reflecting importance regional local climate soil conditions. Adapting management increase forest resilience gaining importance, given expected further dry sites Switzerland.

Language: Английский

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Mechanisms and Impacts of Earth System Tipping Elements

Reviews of Geophysics, Journal Year: 2023, Volume and Issue: 61(1)

Published: Feb. 16, 2023

Abstract Tipping elements are components of the Earth system which may respond nonlinearly to anthropogenic climate change by transitioning toward substantially different long‐term states upon passing key thresholds or “tipping points.” In some cases, such changes could produce additional greenhouse gas emissions radiative forcing that compound global warming. Improved understanding tipping is important for predicting future risks and their impacts. Here we review mechanisms, predictions, impacts, knowledge gaps associated with 10 notable proposed be elements. We evaluate approaching critical whether shifts manifest rapidly over longer timescales. Some have a higher risk crossing points under middle‐of‐the‐road pathways will possibly affect major ecosystems, patterns, and/or carbon cycling within 21st century. However, literature assessing scenarios indicates strong potential reduce impacts many through mitigation. The studies synthesized in our suggest most do not possess abrupt years, exhibit behavior, rather responding more predictably directly magnitude forcing. Nevertheless, uncertainties remain elements, highlighting an acute need further research modeling better constrain risks.

Language: Английский

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