Why models underestimate West African tropical forest primary productivity

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Ноя. 6, 2024

Abstract Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent study indicated that West African have among highest gross primary productivity (GPP) observed, contradicting models rank them lower than Amazonian forests. Here, we show possible reasons for this data-model mismatch. We found biometric GPP measurements on average 56.3% higher multiple global products at sites. The underestimation largely disappears when standard photosynthesis model is informed by local field-measured values (a) fractional absorbed photosynthetic radiation (fAPAR), and (b) traits. Remote sensing systematically underestimate fAPAR (33.9% sites) cloud contamination issues. highlights potential widespread carbon cycling hints ways forward input data improvement.

Язык: Английский

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Coordination of photosynthetic traits across soil and climate gradients

Global Change Biology, Год журнала: 2022, Номер 29(3), С. 856 - 873

Опубликована: Окт. 24, 2022

"Least-cost theory" posits that C3 plants should balance rates of photosynthetic water loss and carboxylation in relation to the relative acquisition maintenance costs resources required for these activities. Here we investigated dependency traits on climate soil properties using a new Australia-wide trait dataset spanning 528 species from 67 sites. We tested hypotheses relatively cold or dry sites, more fertile would typically operate at greater CO2 drawdown (lower ratio leaf internal ambient , Ci :Ca ) during light-saturated photosynthesis, higher N per area (Narea capacity (Vcmax 25 given rate stomatal conductance vapour, gsw . These results be indicative having than nutrient costs. In general, our were supported. Soil total phosphorus (P) concentration (more weakly) pH exerted positive effects Narea -gsw Vcmax slopes, negative The P effect strengthened when was removed via partial regression. observed similar trends with increasing cation exchange clay content, which affect availability, found explained amounts variation focal as did. Although did, together they up 52% slope relationships 30% individual traits. Soils influenced well their coordination. particular, influence likely reflects Australia's geologically ancient low-relief landscapes highly leached soils. Least-cost theory provides valuable framework understanding trade-offs between resource use plants, including limiting nutrients.

Язык: Английский

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Incorporating the Acclimation of Photosynthesis and Leaf Respiration in the Noah‐MP Land Surface Model: Model Development and Evaluation

Journal of Advances in Modeling Earth Systems, Год журнала: 2025, Номер 17(3)

Опубликована: Март 1, 2025

Abstract Realistic simulation of leaf photosynthetic and respiratory processes is needed for accurate prediction the global carbon cycle. These two systematically acclimate to long‐term environmental changes by adjusting traits (e.g., maximum capacity at 25°C ( V cmax,25 ) respiration rate R 25 )) following increasingly well‐understood principles. While some land surface models (LSMs) now account thermal acclimation, they do so assigning empirical parameterizations individual plant functional types (PFTs). Here, we have implemented an Eco‐Evolutionary Optimality (EEO)‐based scheme represent universal acclimation photosynthesis multiple effects, that therefore requires no PFT‐specific parameterizations, in a standard version widely used LSM, Noah MP. We evaluated model performance with trait data from 5‐year experiment extensive field measurements, flux measurements FLUXNET2015. show observed vary substantially both temporally spatially within same PFT C.V. >20%). Our EEO‐based captures 62% temporal 70% spatial variations (73% 54% ). The underestimates gross primary production 10% versus 2% generates larger spread r (correlation coefficient) across sites (0.79 ± 0.16 vs. 0.84 0.1, mean S.D.). greatly overestimates canopy (bias: ∼200% 8% EEO scheme), resulting less CO 2 uptake terrestrial ecosystems. approach thus simulates climate‐carbon coupling more realistically, fewer parameters.

Язык: Английский

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Improved Estimation of the Gross Primary Production of Europe by Considering the Spatial and Temporal Changes in Photosynthetic Capacity from 2001 to 2016

Remote Sensing, Год журнала: 2023, Номер 15(5), С. 1172 - 1172

Опубликована: Фев. 21, 2023

The value of leaf photosynthetic capacity (Vcmax) varies with time and space, but state-of-the-art terrestrial biosphere models rarely include such Vcmax variability, hindering the accuracy carbon cycle estimations on a large scale. In particular, while European ecosystem is particularly sensitive to climate change, current estimates gross primary production (GPP) in Europe are subject significant uncertainties (2.5 8.7 Pg C yr−1). This study applied process-based Farquhar GPP model (FGM) improve estimation by introducing spatially temporally explicit derived from satellite-based chlorophyll content (LCC) two scales: across multiple eddy covariance tower sites regional Across 19 EuroFLUX selected for independent validation based 9 plant functional types (PFTs), relative biome-specific Vcmax, inclusion LCC-derived improved GPP, coefficient determination (R2) increased 23% root mean square error (RMSE) decreased 25%. values typically parameterized PFT-specific calibrated flux observations or empirical TRY database (which includes 723 data points field measurements). On scale, compared using conventional method fixing TRY-based overestimated annual 0.5 2.9 yr−1 5 31% interannually increasing trend 0.007 0.01 yr−2 14 20%, respectively. spatial pattern interannual change estimated FGM showed general consistency existing studies, our indicated that (including part Russia) had higher assimilation potential (9.4 Our highlighted urgent need develop consistent products high so as reduce global modeling understanding how ecosystems respond change.

Язык: Английский

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Land Surface Greening and CO2 Fertilization More than Offset the Gross Carbon Sequestration Decline Caused by Land Cover Change and the Enhanced Vapour Pressure Deficit in Europe

Remote Sensing, Год журнала: 2023, Номер 15(5), С. 1372 - 1372

Опубликована: Фев. 28, 2023

Satellite observations have revealed strong land surface “greening” (i.e., increases in vegetation greenness or leaf area index (LAI)) the Northern Hemisphere over past few decades. European terrestrial ecosystems are a greening hotspot, but how they respond to greening, climate change, CO2 fertilization, use and cover change (LULCC) other factors is unclear. Here, we assessed these interacting might be combined alter gross primary production (GPP) throughout Europe during period of 2001 2016 using process-based Farquhar GPP model FGM). We found more productive ecosystem most enhancement was explained by LAI (62%) atmospheric concentration (29%). Spatially, spatial signature trends both suggested widespread (72–73% vegetated area) phenomena across Europe, among which 23.7% 13.3% were statistically significant (p < 0.05). The interannual trend estimated FGM (0.55% yr−1) reasonable compared with products (0.47% yr−1 0.92% observed increasing rate (0.62% yr−1). factorial simulations that (+35.5 Pg C yr−2, p 0.01), fertilization (+16.9 temperature warming (+3.7 0.05), enhanced downwards solar radiation (+1.2 > 0.05) contributed enhancement, while vapour pressure deficit (−5.6 Tg 0.01) had negative impacts on GPP, especially 2006 2012, when extreme droughts struck south-eastern Europe. Meanwhile, approximately 1.8% total experienced LULCC from exerted small (−1.3 impact due decreases number pixels (−159 Although effect negative, largest increase occurred forested (+0.9% area). In addition, for annual mean (0.01 m2 m−2 yr−1, 0.001) (22.2 forests higher than those types, suggesting may continue play important roles combating future long-lasting carbon storage potential. These results provide first systematic quantitative analysis driving force assimilation considering variations physiological traits environmental adaptations.

Язык: Английский

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High Productivity at High Latitudes? Photosynthesis and Leaf Ecophysiology in Arctic Forests of the Eocene

Paleoceanography and Paleoclimatology, Год журнала: 2023, Номер 38(8)

Опубликована: Авг. 1, 2023

Abstract The Arctic forests of the Eocene, which thrived under elevated CO 2 , a temperate climate, high precipitation and annually extremely different daylengths, represent quite spectacular no‐analogue habitat Earth's greenhouse past. aim this study was to improve our understanding ecophysiology broad‐leaved deciduous by analyzing leaf photosynthesis tree productivity based on gas exchange modeling for two fossil Eocene sites, Svalbard Ellesmere Island. For this, single‐leaf model that includes heat transfer senescence derived. Environmental conditions were available palaeoclimate data level 800 μmol/mol. Additionally, light regimes (diffusivity transmissivity) considered. With model, annual calculated basis temperature day lengths (derived celestial mechanics). To obtain whole tree, single then upscaled canopy model. results indicate enhanced at both latitude sites growing season maximum daylength (24 hr) during late spring early summer. values about 30%–60% higher as mid‐latitude continental European forest, potential polar is in range extant tropical forests. In contrast speculations, no evidence selective advantage large size—as shown various leaves from sites—could be found.

Язык: Английский

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Satellite-observed increasing coupling between vegetation productivity and greenness in the semiarid Loess Plateau of China is not captured by process-based models

The Science of The Total Environment, Год журнала: 2023, Номер 906, С. 167664 - 167664

Опубликована: Окт. 11, 2023

Язык: Английский

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Impacts of climate timescale on the stability of trait–environment relationships

New Phytologist, Год журнала: 2023, Номер 241(6), С. 2423 - 2434

Опубликована: Ноя. 30, 2023

Summary Predictive relationships between plant traits and environmental factors can be derived at global regional scales, informing efforts to reorient ecological models around functional traits. However, in a changing climate, the variables used as predictors such are far from stationary. This could yield errors trait–environment model predictions if timescale is not accounted for. Here, dependence of investigated by regressing situ trait measurements specific leaf area, nitrogen content, wood density on local climate characteristics summarized across several increasingly long timescales. We identify contrasting responses timescale. Leaf best predicted recent timescales, while longer term memory trait. The use sub‐optimal timescales reduces accuracy resulting relationships. study concludes that respond conditions tissue lifespans rather than long‐term normals, even large spatial scales where multiple physiological mechanisms drive change. Thus, determining with temporally relevant may critical for predicting change nonstationary system.

Язык: Английский

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An Elevated CO2 Concentration Improves the Photosynthetic Efficiency and Grain Yield of Rice Plants but Concurrently Increases the Nitrogen Fertilizer

Journal of soil science and plant nutrition, Год журнала: 2024, Номер 24(2), С. 3377 - 3388

Опубликована: Апрель 10, 2024

Язык: Английский

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Improved global estimation of seasonal variations in C3 photosynthetic capacity based on eco-evolutionary optimality hypotheses and remote sensing

Remote Sensing of Environment, Год журнала: 2024, Номер 313, С. 114338 - 114338

Опубликована: Авг. 8, 2024

Язык: Английский

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