Four ways to define the growing season

Ecology Letters, Journal Year: 2023, Volume and Issue: 26(8), P. 1277 - 1292

Published: June 14, 2023

What is addressed as growing season in terrestrial ecosystems one of the main determinants annual plant biomass production globally. However, there no well-defined concept behind. Here, we show different facets what might be termed season, each with a distinct meaning: (1) time period during which or part it actually grows and produces new tissue, irrespective net carbon gain (growing sensu stricto). (2) The defined by developmental, that is, phenological markers (phenological season). (3) vegetation whole achieves its primary (NPP) ecosystem (NEP), expressed (productive season) (4) plants could potentially grow based on meteorological criteria (meteorological We hypothesize duration such 'window opportunity' strong predictor for NPP at global scale, especially forests. These definitions have implications understanding modelling growth production. common view variation phenology proxy productivity misleading, often resulting unfounded statements potential consequences climatic warming sequestration.

Language: Английский

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Widespread and complex drought effects on vegetation physiology inferred from space

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 15, 2023

Abstract The response of vegetation physiology to drought at large spatial scales is poorly understood due a lack direct observations. Here, we study responses related photosynthesis, evaporation, and water content using remotely sensed data, isolate physiological machine learning technique. We find that functional decreases are largely driven by the downregulation such as stomatal conductance light use efficiency, with strongest in water-limited regions. Vegetation wet regions also result discrepancy between structural changes under severe drought. similar patterns simulations from soil–plant–atmosphere continuum model coupled radiative transfer model. Observation-derived across space mainly controlled aridity additionally modulated abnormal hydro-meteorological conditions types. Hence, isolating quantifying enables better understanding ecosystem biogeochemical biophysical feedback modulating climate change.

Language: Английский

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Tree water uptake patterns across the globe

New Phytologist, Journal Year: 2024, Volume and Issue: 242(5), P. 1891 - 1910

Published: April 22, 2024

Plant water uptake from the soil is a crucial element of global hydrological cycle and essential for vegetation drought resilience. Yet, knowledge how distribution depth (WUD) varies across species, climates, seasons scarce relative to our aboveground plant functions. With literature review, we found that average WUD varied more among biomes than functional types (i.e. deciduous/evergreen broadleaves conifers), illustrating importance hydroclimate, especially precipitation seasonality, on WUD. By combining records rooting with WUD, observed consistently deeper maximum largest differences in arid regions - indicating deep taproots act as lifelines while not contributing majority uptake. The most ubiquitous observation was woody plants switch sources layers highest availability within short timescales. Hence, seasonal shifts occur globe when shallow soils are drying out, allowing continued transpiration hydraulic safety. While there still significant gaps understanding consistency ecosystems allows integration existing into next generation process models.

Language: Английский

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Remote sensing of root zone soil moisture: A review of methods and products

Journal of Hydrology, Journal Year: 2025, Volume and Issue: 656, P. 133002 - 133002

Published: March 5, 2025

Language: Английский

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Drought thresholds that impact vegetation reveal the divergent responses of vegetation growth to drought across China

Global Change Biology, Journal Year: 2023, Volume and Issue: 30(1)

Published: Oct. 29, 2023

Abstract Identifying droughts and accurately evaluating drought impacts on vegetation growth are crucial to understanding the terrestrial carbon balance across China. However, few studies have identified critical thresholds that impact China's growth, leading large uncertainty in assessing ecological consequences of droughts. In this study, we utilize gridded surface soil moisture data satellite‐observed normalized difference index (NDVI) assess response China during 2001–2018. Based nonlinear relationship between changing stress coincident anomalies NDVI growing season, derive spatial patterns satellite‐based ( T SM ) via a framework for detecting combining methods feature extraction, coincidence analysis, piecewise linear regression. The values represent percentile‐based threshold levels, with smaller corresponding more negative moisture. On average, is at 8.7th percentile detectable 64.4% vegetated lands, lower North Jianghan Plain higher Inner Mongolia Plateau. Furthermore, forests commonly than grasslands. We also find agricultural irrigation modifies croplands Sichuan Basin. For future projections, Earth System Models predict regions will face an increasing risk drought, Hexi Corridor‐Hetao Shandong Peninsula become hotspots drought. This study has important implications provides scientific reference effective ecomanagement ecosystems.

Language: Английский

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Enhanced prediction of vegetation responses to extreme drought using deep learning and Earth observation data

Ecological Informatics, Journal Year: 2024, Volume and Issue: 80, P. 102474 - 102474

Published: Jan. 19, 2024

The advent of abundant Earth observation data enables the development novel predictive methods for forecasting climate impacts on state and health terrestrial ecosystems. Here, we predict spatial temporal variations land surface reflectance vegetation greenness, measuring density green active foliage area, conditioned current past weather local topography. We train two alternative recurrent deep learning models that combine Long Short-Term Memory cells with convolutional layers (ConvLSTM) spatially resolved deviation across a heterogeneous landscape from specified initial state. Using diverse ecosystems cover types Europe following standardized model evaluation framework (EarthNet2021 Challenge), our results indicate increased performance in predicting greenness during extreme drought events presented here, compared to currently published benchmarks. This demonstrates how optical time series enable an early-warning responses climatic events, such as drought-related loss foliage.

Language: Английский

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Influence of irrigation on root zone storage capacity estimation

Hydrology and earth system sciences, Journal Year: 2024, Volume and Issue: 28(10), P. 2313 - 2328

Published: May 31, 2024

Abstract. Vegetation plays a crucial role in regulating the water cycle through transpiration, which is flux from subsurface to atmosphere via roots. The amount and timing of transpiration controlled by interplay seasonal energy supply. latter strongly depends on size root zone storage capacity (Sr), represents maximum accessible volume that vegetation can use for transpiration. Sr primarily influenced hydroclimatic conditions, as optimizes its system such way it guarantees uptake overcomes dry periods. estimates are commonly derived deficits result phase shift between signals inflow (i.e., precipitation) outflow evaporation). In irrigated croplands, irrigation serves an additional input into zone. However, this aspect has been ignored many studies, extent influences never comprehensively quantified. study, our objective quantify influence identify regional differences therein. To end, we integrated two methods, based respective area fractions, estimation. We evaluated effects compared with do not consider sample 4856 catchments globally varying degrees activity. Our results show consistently decreased when considering irrigation, larger effect area. For fraction exceeding 10 %, median decrease was 19 23 mm corresponding decreases 12 % 15 respectively. most tropical climates. relative largest temperate demonstrate, first time, considerable over croplands. This strong snowmelt have previously documented precipitation falling snow.

Language: Английский

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Regional estimates of gross primary production applying the Process-Based Model 3D-CMCC-FEM vs. Remote-Sensing multiple datasets

European Journal of Remote Sensing, Journal Year: 2024, Volume and Issue: 57(1)

Published: Jan. 9, 2024

Process-based Forest Models (PBFMs) offer the possibility to capture important spatial and temporal patterns of carbon fluxes stocks in forests. Yet, their predictive capacity should be demonstrated not only at stand-level but also context broad heterogeneity. We apply a stand scale PBFM (3D-CMCC-FEM) spatially explicit manner 1 km resolution southern Italy. developed methodology initialize model that includes information derived from integration Remote Sensing (RS) National Inventory (NFI) data regional forest maps characterize structural features main species. Gross primary production (GPP) is simulated over 2005–2019 period capability simulating GPP evaluated both aggregated as species-level through multiple independent sources based on different nature RS-based products. show able reproduce most (~2800 km2) (32 years total) observed seasonal, annual interannual time scales, even species-level. These promising results open confindently applying 3D-CMCC-FEM investigate forests' behaviour under climate environmental variability large areas across highly variable ecological bio-geographical heterogeneity Mediterranean region.

Language: Английский

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Toward a common methodological framework for the sampling, extraction, and isotopic analysis of water in the Critical Zone to study vegetation water use

Wiley Interdisciplinary Reviews Water, Journal Year: 2024, Volume and Issue: 11(4)

Published: March 5, 2024

Abstract The analysis of the stable isotopic composition hydrogen and oxygen in water samples from soils plants can help to identify sources vegetation uptake. This approach requires that heterogeneous nature plant soil matrices is carefully accounted for during experimental design, sample collection, extraction analyses. comparability shortcomings different methods extracting analyzing have been discussed specialized literature. Yet, despite insightful comparisons benchmarking methodologies laboratories worldwide, community still lacks a roadmap guide extraction, analyses, many practical issues potential users remain unresolved: example, which (soil or plant) pool(s) does extracted represent? These constitute hurdle implementation by newcomers. Here, we summarize discussions led framework COST Action WATSON (“WATer isotopeS critical zONe: groundwater recharge transpiration”—CA19120). We provide guidelines (1) sampling material analysis, (2) laboratory situ (3) measurements composition. highlight importance considering process chain as whole, design minimize biased estimates relative contribution conclude acknowledging some limitations this methodology advice on collection key environmental parameters prior article categorized under: Science Water > Hydrological Processes Environmental Change Extremes

Language: Английский

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A brief history of the thermal IR-based Two-Source Energy Balance (TSEB) model – diagnosing evapotranspiration from plant to global scales

Agricultural and Forest Meteorology, Journal Year: 2024, Volume and Issue: 350, P. 109951 - 109951

Published: March 19, 2024

Thermal infrared (TIR) remote sensing of the land-surface temperature (LST) provides an invaluable diagnostic surface fluxes and vegetation state, from plant sub-field scales up to regional global coverage. However, without proper consideration nuances remotely sensed LST signal, TIR imaging can give poor results for estimating sensible latent heating. For example, sensor view angle, atmospheric impacts, differential coupling soil canopy sub-pixel elements with overlying atmosphere affect use satellite-based retrievals in modeling systems. A concerted effort address value perceived shortcomings TIR-based culminated Workshop on Remote Sensing Energy Water Balance, held La Londe les Maures, France September 1993. One outcomes this workshop was Two-Source Balance (TSEB) model, which has fueled research applications over a range spatial scales. In paper we provide some historical context development TSEB TSEB-based multi-scale systems (ALEXI/DisALEXI) aimed at providing physically based, estimates heating (evapotranspiration, or ET, mass units) other energy fluxes. Applications ET are discussed: drought monitoring yield estimation, water forest management, data assimilation into – assessment prognostic New focuses augmenting temporal sampling afforded thermal bands by integrating cloud-tolerant, microwave-based information, as well evaluating capabilities separating evaporation transpiration components. While demonstrated promise supplying stress information down scales, improved operational may be best realized conjunction ensemble such OpenET, effectively combine strengths multiple retrieval approaches.

Language: Английский

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