Linking plant hydraulics and the fast–slow continuum to understand resilience to drought in tropical ecosystems

New Phytologist, Journal Year: 2021, Volume and Issue: 230(3), P. 904 - 923

Published: Feb. 11, 2021

Summary Tropical ecosystems have the highest levels of biodiversity, cycle more water and absorb carbon than any other terrestrial ecosystem on Earth. Consequently, these are extremely important components Earth’s climatic system biogeochemical cycles. Plant hydraulics is an essential discipline to understand predict dynamics tropical vegetation in scenarios changing availability. Using published plant hydraulic data we show that trade‐off between drought avoidance (expressed as deep‐rooting, deciduousness capacitance) safety (P50 – potential when plants lose 50% their maximum conductivity) a major axis physiological variation across ecosystems. We also propose novel independent trait linking vulnerability failure margin (HSM)) growth, where inherent fast‐growing lower HSM compared slow‐growing plants. surmise soil nutrients fundamental drivers community assembly determining distribution abundance slow‐safe/fast‐risky strategies. conclude showing including either growth‐HSM or resistance‐avoidance models can make simulated rainforest communities substantially vulnerable similar without trade‐off. These results suggest need represent axes accurately project functioning

Language: Английский

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Modelling water fluxes in plants: from tissues to biosphere

New Phytologist, Journal Year: 2019, Volume and Issue: 222(3), P. 1207 - 1222

Published: Jan. 13, 2019

Summary Models of plant water fluxes have evolved from studies focussed on understanding the detailed structure and functioning specific components soil–plant–atmosphere ( SPA ) continuum to architectures often incorporated inside eco‐hydrological terrestrial biosphere TB model schemes. We review here historical evolution this field, examine basic a simplified individual‐based transport, highlight selected applications for ecological problems conclude by examining outstanding issues requiring further improvements in modelling vegetation fluxes. particularly emphasise related scaling tissue‐level traits predictions representation nonlinear hysteretic behaviour soil–xylem hydraulics need incorporate knowledge within broader frameworks strategies their consequences predicting community demography dynamics.

Language: Английский

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Embolism resistance drives the distribution of Amazonian rainforest tree species along hydro‐topographic gradients

New Phytologist, Journal Year: 2018, Volume and Issue: 221(3), P. 1457 - 1465

Published: Oct. 8, 2018

Summary Species distribution is strongly driven by local and global gradients in water availability but the underlying mechanisms are not clear. Vulnerability to xylem embolism (P 50 ) a key trait that indicates how species cope with drought might explain plant patterns across environmental gradients. Here we address its role on sorting along hydro‐topographical gradient central Amazonian rainforest examine variance at community scale. We measured P for 28 tree species, soil properties estimated hydrological niche of each using an indicator distance table ( HAND ). found large hydraulic diversity, covering as much 44% angiosperm variation . show : contributes segregation hydro‐topographic Amazon, thus coexistence; result repeated evolutionary adaptation within closely related taxa; associated tolerance P‐poor soils, suggesting evolution stress‐tolerance syndrome nutrients drought; higher trees valleys than uplands. The observed diversity association topography has important implications modelling predicting forest resilience climate change.

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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Sensitivity of South American tropical forests to an extreme climate anomaly

Nature Climate Change, Journal Year: 2023, Volume and Issue: 13(9), P. 967 - 974

Published: Sept. 1, 2023

Abstract The tropical forest carbon sink is known to be drought sensitive, but it unclear which forests are the most vulnerable extreme events. Forests with hotter and drier baseline conditions may protected by prior adaptation, or more because they operate closer physiological limits. Here we report that in South American climates experienced greatest impacts of 2015–2016 El Niño, indicating greater vulnerability temperatures drought. long-term, ground-measured tree-by-tree responses 123 plots across America show biomass ceased during event balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha −1 per year). However, intact overall were no sensitive Niño than previous less intense events, remaining a key defence against climate change as long protected.

Language: Английский

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Modelling tropical forest responses to drought and El Niño with a stomatal optimization model based on xylem hydraulics

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2018, Volume and Issue: 373(1760), P. 20170315 - 20170315

Published: Oct. 8, 2018

The current generation of dynamic global vegetation models (DGVMs) lacks a mechanistic representation responses to soil drought, impairing their ability accurately predict Earth system future climate scenarios and climatic anomalies, such as El Niño events. We propose simple numerical approach model plant drought coupling stomatal optimality theory hydraulics that can be used in (DGVMs). is validated against stand-scale forest transpiration ( E ) observations from long-term experiment the response three Amazonian sites anomalies during twentieth century. show our optimization produces realistic environmental conditions simulate how tropical responds seasonal, even drought. Our predicts stronger cumulative effect Amazon exposed years than captured by alternative empirical schemes. contrasting between factors highlight utility hydraulically-based represent DGVMs. This article part discussion meeting issue ‘The impact 2015/2016 on terrestrial carbon cycle: patterns, mechanisms implications’.

Language: Английский

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Global tree-ring analysis reveals rapid decrease in tropical tree longevity with temperature

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(52), P. 33358 - 33364

Published: Dec. 14, 2020

Forests are the largest terrestrial biomass pool, with over half of this stored in highly productive tropical lowland forests. The future evolution forest depends critically on response tree longevity and growth rates to climate. We present an analysis variation rate using tree-ring data 3,343 populations 438 species assess how climate controls across world biomes. Tropical trees grow, average, two times faster compared from temperate boreal biomes live significantly shorter, average (186 ± 138 y 322 201 outside tropics). At global scale, covary strongly temperature. Within warm lowlands, where broadleaf dominate vegetation, we find consistent decreases increasing aridity, as well a pronounced reduction above mean annual temperatures 25.4 °C. These independent effects temperature water availability tropics theoretical predictions increases evaporative demands at leaf level under warmer drier could explain observed mortality forests, including Amazon, shifts composition western Africa. Our results suggest that conditions supporting only lower lowlands likely expand especially climates.

Language: Английский

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Amazonia trees have limited capacity to acclimate plant hydraulic properties in response to long‐term drought

Global Change Biology, Journal Year: 2020, Volume and Issue: 26(6), P. 3569 - 3584

Published: Feb. 15, 2020

Abstract The fate of tropical forests under future climate change is dependent on the capacity their trees to adjust drier conditions. withstand drought likely be determined by traits associated with hydraulic systems. However, data whether can when experiencing remain rare. We measured plant (e.g. conductivity and embolism resistance) system status leaf water potential, native safety margin) >150 from 12 genera (36 species) spanning a stem size range 14 68 cm diameter at breast height world's only long‐running forest experiment. Hydraulic showed no adjustment following 15 years experimentally imposed moisture deficit. This failure resulted in these drought‐stressed significantly lower potentials, higher, but variable, levels branches. result suggests that damage caused elevated one key drivers drought‐induced mortality long‐term soil demonstrate some changed tree size, however, direction magnitude was controlled taxonomic identity. Our results suggest Amazonian trees, both small large, have limited acclimate systems droughts, potentially making them more risk mortality.

Language: Английский

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Linking drought‐induced xylem embolism resistance to wood anatomical traits in Neotropical trees

New Phytologist, Journal Year: 2020, Volume and Issue: 229(3), P. 1453 - 1466

Published: Sept. 23, 2020

Summary Drought‐induced xylem embolism is considered to be one of the main factors driving mortality in woody plants worldwide. Although several structure–functional mechanisms have been tested understand anatomical determinants resistance, there a need study this topic by integrating data for many species. We combined optical, laser, and transmission electron microscopy investigate vessel diameter, grouping, pit membrane ultrastructure 26 tropical rainforest tree species across three major clades (magnoliids, rosiids, asteriids). then related these observations previously published on drought‐induced with phylogenetic analyses. Vessel were all predictive but weak power. While thickness was trait when vestured pits taken into account, diameter‐to‐thickness ratio suggests strong importance deflection resistance membrane. However, analyses weakly support adaptive coevolution. Our results emphasize functional significance membranes air‐seeding trees, highlighting also their mechanical properties due link between ratio. Finding coevolution remains challenging.

Language: Английский

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Multi-Omics Research Reveals the Effects of the ABA-Regulated Phenylpropanoid Biosynthesis Pathway on the UV-B Response in Rhododendron chrysanthum Pall.

Plants, Journal Year: 2025, Volume and Issue: 14(1), P. 101 - 101

Published: Jan. 1, 2025

The growing depletion of the ozone layer has led to increased ultraviolet B (UV-B) radiation, prompting plants like alpine Rhododendron chrysanthum Pall. (R. chrysanthum) adapt these harsh conditions. This study explored how abscisic acid (ABA) signaling influences R. chrysanthum’s metabolic responses under UV-B stress. was treated with radiation and exogenous ABA for widely targeted metabolomics, transcriptomics, proteomics assays, relevant chlorophyll fluorescence parameters were also determined. It observed that stress negatively impacts plant’s photosynthetic machinery, disrupting multiple processes. Multi-omics analysis revealed application mitigates detrimental effects on photosynthesis bolsters antioxidant defenses. Additionally, both exposure treatment significantly influenced phenylpropanoid biosynthesis pathway, activating key enzyme genes, such as 4CL, CCR, HCT. highlighted MYB–bHLH–WD40 (MBW) complex’s role in regulating this pathway its interaction components. These findings underscore ABA’s crucial function improving plant resistance offer novel insights into biology.

Language: Английский

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