Critical slowing down of the Amazon forest after increased drought occurrence

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(22)

Published: May 20, 2024

Dynamic ecosystems, such as the Amazon forest, are expected to show critical slowing down behavior, or slower recovery from recurrent small perturbations, they approach an ecological threshold a different ecosystem state. Drought occurrences becoming more prevalent across Amazon, with known negative effects on forest health and functioning, but their actual role in patterns still remains elusive. In this study, we evaluate effect of trends extreme drought temporal autocorrelation (TAC) satellite-derived indices vegetation activity, indicator down, between 2001 2019. Differentiating frequency, intensity, duration, investigate respective response. Our results indicate that intensity droughts is important driver than although impacts vary regions. addition, areas variable precipitation already less ecologically stable need fewer induce down. We present findings indicating most region does not increasing trend TAC. However, predicted increase frequency could potentially transition significant portions into state altered functionality.

Language: Английский

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Drought Mitigation of Populus euphratica by Microenvironmental Changes Within Forest Gaps in Flooded and Non-Flooded Areas

Forests, Journal Year: 2025, Volume and Issue: 16(2), P. 292 - 292

Published: Feb. 8, 2025

Populus euphratica is the only dominant tree species of desert riparian forest in Tarim River Basin and faces a great threat drought. Policy-based artificial water delivery projects are an effective engineering method to mitigate drought reduce degradation forests. Forest gaps have been shown be primary mode regeneration. However, little known about growth status P. various arid zone habitats, particularly light complex diverse microenvironmental alterations understory. This study quantified effects flooded areas on changes The relationships between changes, soil physicochemical properties, physiological characteristics were investigated through cross-experiment that compared whether process was existed. results revealed gap increased diversity conditions ground; floods decreased temperature by 1.94 °C while they air humidity 8.19%. Flooding improved vertical distribution properties within also altering content indicators different directions. In research area, peroxidase activity (POD) exhibited significant differences (p < 0.05) understory euphratica, all after flooding. Changes microenvironments features together play important ecological role mitigating euphratica. These provide actionable theoretical basis for efficient management forests sustainable development zones.

Language: Английский

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Avaliação remota como alternativa de monitoramento da restauração na região de Carajás, Pará

Biodiversidade Brasileira, Journal Year: 2025, Volume and Issue: 15(1), P. 70 - 81

Published: March 10, 2025

O monitoramento constitui etapa fundamental da restauração, pois permite avaliar a evolução dessa iniciativa e assim promover o manejo adaptativo das áreas. Este trabalho teve como objetivo efetividade do uso de imagens satélite alta resolução para monitorar restauração em pequenas Monitoramos 25 áreas, utilizando Coleção BETA MapBiomas, que inclui mapas anuais cobertura terra período 2016 2022, com 10 m resolução. Para determinar dinâmica solo utilizamos programa QGIS. As áreas monitoradas têm 0,03 8,7 ha pretérito, principalmente, pastagem. Observamos uma intensa ao longo dos anos avaliação (2016 2022), muito mais voltada antrópico restauração. classes predominante nas foram: pastagem, outras não vegetadas formação florestal. somatório no ano 2016, foi 937,69 ha, passando 649,91, 2022. A área classificada floresta 1,310 1,849 Assim os dados campo, feita por mostrou avaliada apresenta resultados pouco efetivos, tendo vista aumento vegetal consequente redução pastagem foram observados forma consistente. Esse fato demonstra importância adoção estratégias contemplem as especificidades iniciativas voltadas Deste modo, fica demonstrado geotecnologias são ferramentas importantes vez é possível indicar porcentagem coberta vegetação classificar aquelas interesse proximidades, favorecendo conectividade entre fragmentos.

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Monitoring Terrestrial Ecosystem Resilience Using Earth Observation Data: Identifying Consensus and Limitations Across Metrics

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(3)

Published: March 1, 2025

ABSTRACT Resilience is a key feature of ecosystem dynamics reflecting system's ability to resist and recover from environmental perturbations. Slowing down in the rate recovery has been used as an early‐warning signal for abrupt transitions. Recent advances Earth observation (EO) vegetation data provide capability capture broad‐scale resilience patterns identify regions experiencing loss. However, proliferation methods evaluating using EO introduced significant uncertainty, leading contradictory estimates across approximately 73% Earth's land surface. To reconcile these perspectives, we review range associated metrics that aspects data. Using principal component analysis, empirically test relationships between most widely explore emergent within among world's biomes. Our analysis reveals 10 aggregate into four core components dynamics, highlighting multidimensional nature resilience. We also find ecosystems with slower are more resistant drought extremes. Furthermore, vary biomes types. These results illustrate inherent differences natural systems highlight need careful consideration when findings valuable insights identifying global patterns, which critically needed inform policy decisions guide conservation efforts globally.

Language: Английский

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Shifted vegetation resilience from loss to gain driven by changes in water availability and solar radiation over the last two decades in Southwest China

Agricultural and Forest Meteorology, Journal Year: 2025, Volume and Issue: 368, P. 110543 - 110543

Published: April 14, 2025

Language: Английский

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How Do Changes in Grassland Phenology and Its Responses to Extreme Climatic Events in Central Asia?

Land, Journal Year: 2025, Volume and Issue: 14(1), P. 160 - 160

Published: Jan. 14, 2025

Extreme climate events have become more frequent under global warming, significantly affecting vegetation phenology and carbon cycles in Central Asia. However, the mediating effects of intensity compound drought heat (CDHEs) moisture (CMHEs) on grassland their trends relative contributions to over time remained unclear. Based calculation results (CEs), this study used trend analysis, partial least squares regression structural equation modeling (PLS-SEM), ridge analysis investigate effect temporal contribution CEs Asia, magnitude sensitivity CEs. This revealed that start season (SOS) was advanced by 0.4 d·a−1, end (EOS) delayed 0.5 length (LOS) extended 0.8 d·a−1 1982–2022. The duration CDHEs (0−37 days) greater than CMHEs (0−9 direct were generally negative, except for positive LOS. indirect temperature precipitation through phenology. consistently CMHEs, both curves showed a significant upward trend. higher its at 0.79 (SOS), 1.18 (EOS), 0.72 (LOS). Our emphasize Under influence LOS will further lengthen future.

Language: Английский

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Restoration of secondary forest in the Greater Mekong Subregion struggles to offset primary forest carbon losses

Global and Planetary Change, Journal Year: 2025, Volume and Issue: unknown, P. 104796 - 104796

Published: March 1, 2025

Language: Английский

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Resilience Indicators for Tropical Rainforests in a Dynamic Vegetation Model

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(12)

Published: Dec. 1, 2024

ABSTRACT Tropical forests and particularly the Amazon rainforest have been identified as potential tipping elements in Earth system. According to a dynamical systems theory, decline forest resilience preceding shift savanna‐like biome could manifest increasing autocorrelation of biomass time series. Recent satellite records indeed exhibit such trend also show larger autocorrelation, indicative reduced resilience, drier regions. However, it is unclear which processes underlie these observational findings on scales they operate. Here, we investigate determine tropical stand‐alone, state‐of‐the‐art dynamic global vegetation model LPJmL. We find that higher dry climates than wet (approx. 0.75 vs. 0.2, for lag 10 years), qualitatively agrees with observations. By constructing version LPJmL by disabling enabling certain model, (i) this pattern associated population dynamics operating different (ii) sensitive allocation carbon pools, especially years stress. Both are highly uncertain, oversimplified or even lacking most system models. Our results indicate observed spatial variations trends indicators may be explained local physiological ecological mechanisms alone, without climate–vegetation feedbacks. In principle, consistent view responding climate change locally does not necessarily need approach one large‐scale point, although latter cannot ruled out based our findings.

Language: Английский

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Precipitation sensitivity of vegetation growth in southern China depends on geological settings

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 643, P. 131916 - 131916

Published: Sept. 1, 2024

Language: Английский

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