Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests

Journal of Geophysical Research Biogeosciences, Journal Year: 2020, Volume and Issue: 125(8)

Published: June 30, 2020

Abstract Selective logging, fragmentation, and understory fires directly degrade forest structure composition. However, studies addressing the effects of degradation on carbon, water, energy cycles are scarce. Here, we integrate field observations high‐resolution remote sensing from airborne lidar to provide realistic initial conditions Ecosystem Demography Model (ED‐2.2) investigate how disturbances affect gross primary production (GPP), evapotranspiration (ET), sensible heat flux (H). We used structural information retrieved samples (13,500 ha) calibrated with 817 inventory plots (0.25 across precipitation gradients in eastern Amazon as ED‐2.2 model. Our results show that magnitude seasonality fluxes were modulated by changes caused degradation. During dry season under typical conditions, severely degraded forests (biomass loss ≥66 %) experienced water stress declines ET (up 34%) GPP 35%) increases H 43%) daily mean ground temperatures 6.5°C) relative intact forests. In contrast, impact energy, carbon markedly diminishes extreme, multiyear droughts, a consequence severe highlight driven not only climate deforestation but also past disturbance degradation, suggesting much broader influence human land use activities tropical ecosystems.

Language: Английский

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Leaf surface water, not plant water stress, drives diurnal variation in tropical forest canopy water content

New Phytologist, Journal Year: 2021, Volume and Issue: 231(1), P. 122 - 136

Published: Feb. 6, 2021

Summary Variation in canopy water content (CWC) that can be detected from microwave remote sensing of vegetation optical depth (VOD) has been proposed as an important measure stress. However, the contribution leaf surface (LW s ), arising dew formation and rainfall interception, to CWC is largely unknown, particularly tropical forests other high‐humidity ecosystems. We compared VOD data Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR‐E) predicted by a plant hydrodynamics model at four sites Brazil spanning gradient. assessed how LW influenced relationship between CWC. The analysis indicates while strongly correlated with ( R 2 = 0.62 across all sites), accounts 61–76% diurnal variation despite being < 10% Ignoring weakens near‐linear reduces consistency variation. variation, however, decreases longer, seasonal inter‐annual, time scales. Our results demonstrate patterns interception driver over ecosystems therefore should accounted when inferring stress measurements.

Language: Английский

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rasterdiv—An Information Theory tailored R package for measuring ecosystem heterogeneity from space: To the origin and back

Methods in Ecology and Evolution, Journal Year: 2021, Volume and Issue: 12(6), P. 1093 - 1102

Published: Feb. 27, 2021

Ecosystem heterogeneity has been widely recognized as a key ecological indicator of several functions, diversity patterns and change, metapopulation dynamics, population connectivity or gene flow.In this paper, we present new R package-rasterdiv-to calculate indices based on remotely sensed data. We also provide an application at the landscape scale demonstrate its power in revealing potentially hidden patterns.The rasterdiv package allows calculating multiple indices, robustly rooted Information Theory, reproducible open-source algorithms.

Language: Английский

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Soil respiration strongly offsets carbon uptake in Alaska and Northwest Canada

Environmental Research Letters, Journal Year: 2021, Volume and Issue: 16(8), P. 084051 - 084051

Published: July 7, 2021

Abstract Soil respiration (i.e. from soils and roots) provides one of the largest global fluxes carbon dioxide (CO 2 ) to atmosphere is likely increase with warming, yet magnitude soil rapidly thawing Arctic-boreal regions not well understood. To address this knowledge gap, we first compiled a new CO flux database for permafrost-affected tundra boreal ecosystems in Alaska Northwest Canada. We then used database, multi-sensor satellite imagery, random forest models assess regional respiration. The includes Respiration Station network chamber-based fluxes, eddy covariance towers. Our site-level data, spanning September 2016 August 2017, revealed that emissions occurred during summer (June–August) were higher sites (1.87 ± 0.67 g –C m −2 d −1 relative (0.94 0.4 ). also observed considerable (boreal: 0.24 0.2 ; tundra: 0.18 0.16 winter (November–March) despite frozen surface conditions. model estimates indicated an annual region-wide loss 591 120 Tg 2016–2017 period. Summer months contributed 58% respiration, 15%, shoulder 27%. In total, offset 54% gross primary productivity (GPP) across study domain. found environments, transitional tundra/boreal ecotones, landscapes recently affected by fire, often exceeded GPP, resulting net source atmosphere. As region continues warm, may increasingly further amplifying climate change.

Language: Английский

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Assessing the impact of drought-land cover change on global vegetation greenness and productivity

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 852, P. 158499 - 158499

Published: Sept. 2, 2022

Language: Английский

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