Significant increase in natural disturbance impacts on European forests since 1950

Global Change Biology, Journal Year: 2022, Volume and Issue: 29(5), P. 1359 - 1376

Published: Dec. 12, 2022

Abstract Over the last decades, natural disturbance is increasingly putting pressure on European forests. Shifts in regimes may compromise forest functioning and continuous provisioning of ecosystem services to society, including their climate change mitigation potential. Although forests are central many policies, we lack long‐term empirical data needed for thoroughly understanding dynamics, modeling them, developing adaptive management strategies. Here, present a unique database >170,000 records ground‐based observations from 1950 2019. Reported confirm significant increase 34 countries, causing an average 43.8 million m 3 disturbed timber volume per year over 70‐year study period. This value likely conservative estimate due under‐reporting, especially small‐scale disturbances. We used machine learning techniques assessing magnitude unreported disturbances, which estimated be between 8.6 18.3 /year. In 20 years, disturbances accounted 16% mean annual harvest Europe. Wind was most important agent period (46% total damage), followed by fire (24%) bark beetles (17%). Bark beetle doubled its share damage years. Forest can profoundly impact (e.g., mitigation), affect regional resource consequently disrupt planning objectives markets. conclude that adaptation changing must placed at core policy debate. Furthermore, coherent homogeneous monitoring system urgently Europe, better observe respond ongoing changes regimes.

Language: Английский

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Tropical tree mortality has increased with rising atmospheric water stress

Nature, Journal Year: 2022, Volume and Issue: 608(7923), P. 528 - 533

Published: May 18, 2022

Language: Английский

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Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

Nature, Journal Year: 2023, Volume and Issue: 617(7959), P. 111 - 117

Published: April 26, 2023

Abstract Tropical forests face increasing climate risk 1,2 , yet our ability to predict their response change is limited by poor understanding of resistance water stress. Although xylem embolism thresholds (for example, $$\varPsi $$ Ψ 50 ) and hydraulic safety margins HSM are important predictors drought-induced mortality 3–5 little known about how these vary across Earth’s largest tropical forest. Here, we present a pan-Amazon, fully standardized traits dataset use it assess regional variation in drought sensitivity trait species distributions long-term forest biomass accumulation. Parameters markedly the Amazon related average rainfall characteristics. Both influence biogeographical distribution tree species. However, was only significant predictor observed decadal-scale changes biomass. Old-growth with wide gaining more than low forests. We propose that this may be associated growth–mortality trade-off whereby trees consisting fast-growing take greater risks risk. Moreover, regions pronounced climatic change, find evidence losing biomass, suggesting operating beyond limits. Continued likely further reduce 6,7 strong implications for carbon sink.

Language: Английский

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Small and slow is safe: On the drought tolerance of tropical tree species

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(8), P. 2622 - 2638

Published: Jan. 10, 2022

Understanding how evolutionary history and the coordination between trait trade-off axes shape drought tolerance of trees is crucial to predict forest dynamics under climate change. Here, we compiled traits related fast-slow stature-recruitment in 601 tropical woody species explore their covariations phylogenetic signals. We found that xylem resistance embolism (P50) determines risk hydraulic failure, while functional significance leaf turgor loss point (TLP) relies on its with water use strategies. P50 TLP exhibit weak signals substantial variation within genera. closely associated axis: slow maintain functioning higher stress. both axes: small more resistant xylem. Lower phosphorus concentration xylem, which suggests a (nutrient drought) stress-tolerance syndrome tropics. Overall, our results imply (1) strong selective pressure forests, result from repeated adaptation taxa, (2) coordinated ecological strategies governing demography. These findings provide physiological basis interpret drought-induced shift toward slow-growing, smaller, denser-wooded observed tropics, implications for restoration programmes.

Language: Английский

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Bridge to the future: Important lessons from 20 years of ecosystem observations made by the OzFlux network

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(11), P. 3489 - 3514

Published: March 22, 2022

Abstract In 2020, the Australian and New Zealand flux research monitoring network, OzFlux, celebrated its 20 th anniversary by reflecting on lessons learned through two decades of ecosystem studies global change biology. OzFlux is a network not only for researchers, but also those ‘next users’ knowledge, information data that such networks provide. Here, we focus eight across topics climate variability, disturbance resilience, drought heat stress synergies with remote sensing modelling. distilling key learned, identify where further needed to fill knowledge gaps improve utility relevance outputs from OzFlux. Extreme variability Australia (droughts flooding rains) provides natural laboratory understanding ecosystems in this time accelerating change. As evidence worsening fire risk emerges, ability these recover disturbances, as cyclones, adaptation resilience disturbance. Drought heatwaves are common occurrences large parts region can tip an ecosystem's carbon budget net CO 2 sink source. Despite responses stress, at sites show their rapidly pivoting back strong upon return favourable conditions. Located under‐represented areas, have potential reducing uncertainties products, provide several opportunities develop new theories our models. The accumulated impacts over last years highlights value long‐term observations managed systems. A future vision includes ongoing newly developed ecophysiologists, ecologists, geologists, sensors modellers.

Language: Английский

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Decoupling between ecosystem photosynthesis and transpiration: a last resort against overheating

Environmental Research Letters, Journal Year: 2022, Volume and Issue: 17(4), P. 044013 - 044013

Published: Feb. 24, 2022

Abstract Ecosystems are projected to face extreme high temperatures more frequently in the near future. Various biotic coping strategies exist prevent heat stress. Controlled experiments have recently provided evidence for continued transpiration woody plants during air temperatures, even when photosynthesis is inhibited. Such a decoupling of and would represent an effective strategy (‘known as leaf or canopy cooling’) lethal temperatures. At ecosystem scale, might dampen development propagation extremes despite further desiccating soils. However, at occurrence this still limited. Here, we aim investigate mechanism using eddy-covariance data thirteen ecosystems located Australia causal graph discovery algorithm. Working half-hourly time resolution, find four which can be classified Mediterranean woodlands. The occurred above 35 ∘ C. nine other investigated sites, found that vegetation CO 2 exchange remained coupled observed Ecosystem characteristics suggest energy balance plays crucial role determining decoupling. Our results highlight value causal-inference approaches analysis complex physiological processes. With regard increasing especially events future climates, types pushed threatening findings coupling leaf-level stomatal conductance, common land surface schemes, may need re-examined applied high-temperature events.

Language: Английский

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Phylogeny and climate explain contrasting hydraulic traits in different life forms of 150 woody Fabaceae species

Journal of Ecology, Journal Year: 2024, Volume and Issue: 112(4), P. 741 - 754

Published: Jan. 23, 2024

Abstract The contrasting hydraulic traits observed among different plant life forms are shaped by entangled environmental and evolutionary processes. However, we lack understanding of the relative importance form, climate phylogeny in explaining variance traits. We analysed seven eleven climatic variables 150 Fabaceae species representing three from 62 sites worldwide, using phylogenetic comparative analyses partitioning. signal found most disappeared after considering indicating that conservatism originated divergence forms. trait‐climate relationships were also phylogenetically dependent, implying trait responses driven together. Variance partitioning showed explained greater variation than form did. Synthesis . climate‐driven still existed with being considered, suggesting this large family may be particularly sensitive to change. Our results emphasise need include adaptation studies under future

Language: Английский

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Hotter drought and trade‐off between fast and slow growth strategies as major drivers of tree‐ring growth variability of global conifers

Journal of Ecology, Journal Year: 2024, Volume and Issue: 112(5), P. 1123 - 1139

Published: March 18, 2024

Abstract Temporal growth variability is an important indicator of ecosystem function under climate change. However, we still lack a unified understanding how conditions, change (trends and variability), nitrogen (N) deposition, functional traits stand factors together affect radial variability. Using global conifer tree‐ring records (123 species from 1780 sites) during 1970–2010 to calculate variability, assessed abiotic directly indirectly via with boosted regression tree structural equation models, examined the differences among continents (North America, Asia Europe). We found: (a) was mainly affected by warm‐induced drought increased at lower latitudes. Climate warming in winter could decrease but this effect far not enough offset threat hotter drought; (b) there existed trade‐off between fast‐ slow‐growing (drought tolerance) strategies for species, traits. Contrary common conjecture, higher tolerance revealed due their occupation more xeric sites, may also because investment leads less remaining growth; (c) older trees conservative strategy, while large scales, taller showed occupying productive sites; (d) moderate N deposition reduce leading conifers adopt fast‐growing strategy (e.g. Asia), long‐term excessive led North America Synthesis . Our results suggest that coniferous forests water‐limited regions should be vulnerable drought, ‘fast–slow’ key regulating effects various on stability. Moreover, future will severely threaten growth, especially old

Language: Английский

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Thirty-eight years of CO<sub>2</sub> fertilization has outpaced growing aridity to drive greening of Australian woody ecosystems

Biogeosciences, Journal Year: 2022, Volume and Issue: 19(2), P. 491 - 515

Published: Jan. 28, 2022

Abstract. Climate change is projected to increase the imbalance between supply (precipitation) and atmospheric demand for water (i.e., increased potential evapotranspiration), stressing plants in water-limited environments. Plants may be able offset increasing aridity because rising CO2 increases use efficiency. fertilization has also been cited as one of drivers widespread “greening” phenomenon. However, attributing size this effect complicated, due part a lack long-term vegetation monitoring interannual- decadal-scale climate variability. In study we asked question how much contributed towards greening. We focused our analysis on broad gradient spanning eastern Australia's woody ecosystems. Next analyzed 38 years satellite remote sensing estimates greenness (normalized difference index, NDVI) examine role ameliorating impacts. Multiple statistical techniques were applied separate CO2-attributable effects greening from changes aridity. Widespread occurred despite warming climate, vapor pressure deficit, repeated record-breaking droughts heat waves. Between 1982–2019 found that NDVI (median 11.3 %) across 90.5 % regions. After masking disturbance (e.g., fire), statistically estimated an 11.7 attributable CO2, broadly consistent with hypothesized theoretical expectation 8.6 efficiency CO2. contrast reports weakening effect, no temporal effect. conclude mitigated aridity, droughts, waves Australia. unable determine whether trees or grasses primary beneficiary CO2-induced efficiency, which implications projecting future ecosystem resilience. A more complete understanding affect non-tree needed.

Language: Английский

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Aridity‐dependent sequence of water potentials for stomatal closure and hydraulic dysfunctions in woody plants

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(7), P. 2030 - 2040

Published: Jan. 19, 2023

The sequence of physiological events during drought strongly impacts plants' overall performance. Here, we synthesized the global data stomatal and hydraulic traits in leaves stems 202 woody species to evaluate variations water potentials for key their along climatic gradient. We found that seasonal minimum potential, turgor loss point, closure leaf stem xylem vulnerability embolism were intercorrelated decreased with aridity, indicating stress drives trait co-selection. In xeric regions, potential occurred at lower than subsequent delayed formation. mesic however, did not pose a threat functions, even slightly more negative embolism. Our study demonstrates dysfunctions plants varies is, adopt conservative prevent severe tissue damage through tighter regulation (isohydric strategy) higher resistance, while riskier via looser (anisohydric maximize carbon uptake cost safety. Integrating both aridity-dependent gap between these into framework process-based vegetation models would improve prediction responses under climate change.

Language: Английский

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