Increasing Tibetan Plateau terrestrial evapotranspiration primarily driven by precipitation

Agricultural and Forest Meteorology, Год журнала: 2022, Номер 317, С. 108887 - 108887

Опубликована: Март 4, 2022

Язык: Английский

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Evidence and attribution of the enhanced land carbon sink

Nature Reviews Earth & Environment, Год журнала: 2023, Номер 4(8), С. 518 - 534

Опубликована: Июль 25, 2023

Язык: Английский

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A daily and 500 m coupled evapotranspiration and gross primary production product across China during 2000–2020

Earth system science data, Год журнала: 2022, Номер 14(12), С. 5463 - 5488

Опубликована: Дек. 15, 2022

Abstract. Accurate high-resolution actual evapotranspiration (ET) and gross primary production (GPP) information is essential for understanding the large-scale water carbon dynamics. However, substantial uncertainties exist in current ET GPP datasets China because of insufficient local ground measurements used model constraint. This study utilizes a water–carbon coupled model, Penman–Monteith–Leuning Version 2 (PML-V2), to estimate 500 m at daily scale. The parameters PML-V2(China) were well calibrated against observations 26 eddy covariance flux towers across nine plant functional types China, indicated by Nash–Sutcliffe efficiency (NSE) 0.75 root mean square error (RMSE) 0.69 mm d−1 ET, respectively, NSE 0.82 RMSE 1.71 g C m−2 GPP. estimates get small Bias 6.28 % high water-balance annual 10 major river basins China. Further evaluations suggest that newly developed product better than other typical products (MOD16A2, SEBAL, GLEAM, MOD17A2H, VPM, EC-LUE) estimating both Moreover, accurately monitors intra-annual variations croplands with dual-cropping system. new data showed that, during 2001–2018, use experienced significant (p<0.001) increase (8.99 yr−2 0.02 mm−1 H2O yr−1, respectively), but non-significant (p>0.05) (0.43 yr−2). indicates vegetation exhibits huge potential sequestration little cost resources. provides great opportunity academic communities various agencies scientific studies applications, freely available https://doi.org/10.11888/Terre.tpdc.272389 (Zhang He, 2022).

Язык: Английский

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Proximal remote sensing: an essential tool for bridging the gap between high‐resolution ecosystem monitoring and global ecology

New Phytologist, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

Summary A new proliferation of optical instruments that can be attached to towers over or within ecosystems, ‘proximal’ remote sensing, enables a comprehensive characterization terrestrial ecosystem structure, function, and fluxes energy, water, carbon. Proximal sensing bridge the gap between individual plants, site‐level eddy‐covariance fluxes, airborne spaceborne by providing continuous data at high‐spatiotemporal resolution. Here, we review recent advances in proximal for improving our mechanistic understanding plant processes, model development, validation current upcoming satellite missions. We provide best practices availability metadata sensing: spectral reflectance, solar‐induced fluorescence, thermal infrared radiation, microwave backscatter, LiDAR. Our paper outlines steps necessary making these streams more widespread, accessible, interoperable, information‐rich, enabling us address key ecological questions unanswerable from space‐based observations alone and, ultimately, demonstrate feasibility technologies critical local global ecology.

Язык: Английский

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Spatial biases of information influence global estimates of soil respiration: How can we improve global predictions?

Global Change Biology, Год журнала: 2021, Номер 27(16), С. 3923 - 3938

Опубликована: Май 2, 2021

Abstract Soil respiration (Rs), the efflux of CO 2 from soils to atmosphere, is a major component terrestrial carbon cycle, but poorly constrained regional global scales. The soil database (SRDB) compilation in situ Rs observations around globe that has been consistently updated with new measurements over past decade. It unclear whether addition data versions produced better‐constrained estimates. We compared two SRDB (v3.0 n = 5173 and v5.0 10,366) determine how additional influenced annual sum, spatial patterns associated uncertainty (1 km resolution) using machine learning approach. A quantile regression forest model parameterized SRDBv3 yielded sum 88.6 Pg C year −1 , 29.9 (mean absolute error) 57.9 (standard deviation) whereas parameterization SRDBv5 96.5 30.2 average 73.4 . Empirically estimated heterotrophic (Rh) v3 v5 were 49.9–50.2 50.1) 53.3–53.5 53.4) respectively. SRDBv5’s inclusion underrepresented regions (e.g., Asia, Africa, South America) resulted overall higher uncertainty. largest differences between models different SRDVB arid/semi‐arid regions. still biased toward northern latitudes temperate zones, so we tested an optimized distribution measurements, which 96.4 ± 21.4 lower These results support current estimates highlight biases influence interpretation provide insights for design environmental networks improve global‐scale

Язык: Английский

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Representativeness assessment of the pan-Arctic eddy covariance site network and optimized future enhancements

Biogeosciences, Год журнала: 2022, Номер 19(3), С. 559 - 583

Опубликована: Фев. 2, 2022

Abstract. Large changes in the Arctic carbon balance are expected as warming linked to climate change threatens destabilize ancient permafrost stocks. The eddy covariance (EC) method is an established technique quantify net losses and gains of between biosphere atmosphere at high spatiotemporal resolution. Over past decades, a growing network terrestrial EC tower sites has been across Arctic, but comprehensive assessment network's representativeness within heterogeneous region still lacking. This creates additional uncertainties when integrating flux data sites, for example upscaling fluxes constrain pan-Arctic budgets therein. study provides inventory (here > = 60∘ N) which also made available online (https://cosima.nceas.ucsb.edu/carbon-flux-sites/, last access: 25 January 2022). Our database currently comprises 120 only 83 listed active, just these active remain operational throughout winter. To map this network, we evaluated similarity environmental conditions observed locations those larger domain based on 18 bioclimatic edaphic variables. allows us assess general level ecosystem domain, while not necessarily reflecting greenhouse gas rates directly. We define two metrics score: one that measures whether location represented by with similar characteristics (ER1) second if minimum representation statistically rigorous extrapolation met (ER4). find half least tower, third enough towers allow reliable extrapolation. When consider methane measurements or year-round (including wintertime) measurements, values drop about 1/5 1/10 respectively. With majority located Fennoscandia Alaska, regions were assigned highest representativeness, large parts Siberia patches Canada classified underrepresented. Across mountainous particularly poorly current observation network. tested three different strategies identify new site upgrades existing optimally enhance While 15 can improve 20 %, upgrading few 10 capture during wintertime their respective ER1 coverage 28 % 33 %. targeted improvement could be shown clearly superior unguided selection therefore leading substantial improvements relatively small investments.

Язык: Английский

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Historically inconsistent productivity and respiration fluxes in the global terrestrial carbon cycle

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Апрель 1, 2022

Abstract The terrestrial carbon cycle is a major source of uncertainty in climate projections. Its dominant fluxes, gross primary productivity (GPP), and respiration (in particular soil respiration, R S ), are typically estimated from independent satellite-driven models upscaled situ measurements, respectively. We combine carbon-cycle flux estimates partitioning coefficients to show that historical global GPP irreconcilable. When we estimate based on measurements some assumptions about :GPP ratios, found the resulted values (bootstrap mean $${149}_{-23}^{+29}$$ 149 − 23 + 29 Pg C yr −1 ) significantly higher than most reported literature ( $${113}_{-18}^{+18}$$ 113 18 ). Similarly, imply (Rs , bootstrap $${68}_{-8}^{+10}$$ 68 8 10 statistically inconsistent with published $${87}_{-8}^{+9}$$ 87 9 although recent, higher, narrowing this gap. Furthermore, ratios spatial averages ratio calculated individual sites as well CMIP6 model results. This discrepancy has implications for our understanding turnover times sensitivity change. Future efforts should reconcile discrepancies associated calculations Rs improve budget.

Язык: Английский

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Practical Guide to Measuring Wetland Carbon Pools and Fluxes

Wetlands, Год журнала: 2023, Номер 43(8)

Опубликована: Ноя. 28, 2023

Abstract Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, dioxide and methane emissions, aquatic C fluxes. However, underlying biogeochemical processes that affect wetland pools fluxes are complex dynamic, making measurements challenging. Over decades research, many observational, experimental, analytical approaches been developed to understand quantify C. Sampling range in their representation from short long timeframes local landscape spatial scales. This review summarizes common cutting-edge methodological for quantifying We first define each major provide rationale importance dynamics. For approach, we clarify what component is measured its temporal representativeness constraints. describe practical considerations such as where when an approach typically used, who can conduct (expertise, training requirements), how conducted, including equipment complexity costs. Finally, key covariates ancillary enhance interpretation findings facilitate model development. The protocols measure soil, water, vegetation, gases also relevant related disciplines ecology. Improved quality consistency data collection reporting across studies will help reduce uncertainties develop management strategies use wetlands nature-based climate solutions.

Язык: Английский

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Upscaling Wetland Methane Emissions From the FLUXNET‐CH4 Eddy Covariance Network (UpCH4 v1.0): Model Development, Network Assessment, and Budget Comparison

AGU Advances, Год журнала: 2023, Номер 4(5)

Опубликована: Сен. 6, 2023

Abstract Wetlands are responsible for 20%–31% of global methane (CH 4 ) emissions and account a large source uncertainty in the CH budget. Data‐driven upscaling fluxes from eddy covariance measurements can provide new independent bottom‐up estimates wetland emissions. Here, we develop six‐predictor random forest model (UpCH4), trained on 119 site‐years flux data 43 freshwater sites FLUXNET‐CH4 Community Product. Network patterns site‐level annual means mean seasonal cycles were reproduced accurately tundra, boreal, temperate regions (Nash‐Sutcliffe Efficiency ∼0.52–0.63 0.53). UpCH4 estimated 146 ± TgCH y −1 2001–2018 which agrees closely with current land surface models (102–181 overlaps top‐down atmospheric inversion (155–200 ). However, diverged both types spatial pattern dynamics tropical We conclude that has potential to produce realistic extra‐tropical will improve more data. To reduce upscaled estimates, researchers could prioritize along humid‐to‐arid climate gradients, major rainforest basins (Congo, Amazon, SE Asia), into monsoon (Bangladesh India) savannah (African Sahel) be paired improved knowledge extent these regions. The monthly products gridded at 0.25° available via ORNL DAAC ( https://doi.org/10.3334/ORNLDAAC/2253

Язык: Английский

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The importance of tropical tree-ring chronologies for global change research

Quaternary Science Reviews, Год журнала: 2025, Номер 355, С. 109233 - 109233

Опубликована: Март 6, 2025

Язык: Английский

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