Climate change is altering ecosystems and will reshape the global distribution of biomes. These shifts can significantly influence biodiversity, ecosystem functions and services that are essential for human livelihoods. Robust assessments of future biome dynamics are therefore urgently needed. Here, we aimed to robustly quantify and map future biome shifts under climate change using a reproducible, multi-model ensemble approach. We employed random forest models to classify outputs from five global vegetation models (GVMs) into 31 observation-based biome maps representing land cover under current climate conditions. Model-derived biome maps showed strong agreement with observation-based maps (average κ=0.77
The Soil Moisture Active Passive Level-4 Terrestrial Carbon Flux model (hereafter referred to as the L4C model) provides daily estimates of net ecosystem CO2222
River floodplains contribute to river ecosystems by supporting high biological productivity and biodiversity. Backwaters, locally called Wando in Japanese, are semi-enclosed water bodies formed along rivers that serve as habitats for aquatic organisms. However, research on the origin of the seepage water supplied to backwater and the associated nutrient supply remains limited. In this study, we investigated the origins and pathways of water and the internal nutrient dynamics (sources, concentrations and composition ratios) using multiple geochemical tracers – ion balance, chromophoric dissolved organic matter (CDOM), 222Rn, stable hydrogen and oxygen isotope ratios in water (δ2H and δ18O–H2O), and stable nitrogen and oxygen isotope ratios in nitrate (δ15N and δ18O–NO3) – at three distinct backwaters sites within a 5 km section of the middle reaches of an urban river (Tama River) in Tokyo. Each geochemical tracer exhibited significantly different values between the surrounding shallow groundwater and the main river along the backwaters, serving as an effective indicator for evaluating the contribution of both sources to the water supplied to the backwaters. The water sources differed not only among the three backwaters locations within a short river section (5 km) but also across seasons. River water exhibited relatively high phosphate concentrations (3.4–12.4 µmol L−1) and low dissolved silicate (DSi) concentrations (157–218 µmol L−1), whereas shallow groundwater exhibited lower phosphate (0.7–1.3 µmol L−1) and higher DSi concentrations (236–730 µmol L−1). Although no significant difference in DIN (NO
Many river deltas are aquatic hot spots for carbon dioxide (CO2) emissions to the atmosphere. Their patchwork of wetlands, lakes, channels, and river reaches often complicates the analysis of CO2CO2, O2CO2O2CO2O2-depleted and CO2-rich wetland water into the downstream river sections was most pronounced during spring floods with apparent mixing rations of up to 13 %–25 % depending on the station. In a delta channel draining wetland waters, average CO2CO2CO2CO2
Soil freeze-thaw cycles (FTCs) exert substantial effects on the mineralization of soil organic carbon (SOC), particularly in high-altitude and -latitude cold regions. Ongoing climate change is altering FTC frequency and duration, yet the responses of SOC mineralization to such changes remain poorly understood, limiting our ability to predict carbon cycle-climate feedbacks. Here, we incubated soils from two depths across three sites to quantify how FTC regimes regulate SOC mineralization and explore underlying controls. Across all treatments, we observed a pronounced thaw-induced pulse of CO22
The Labrador Sea is a key region for carbon dioxide uptake characterized by deep mixing during winter that supplies nutrients to the upper water column and fuels extensive phytoplankton blooms in spring. Yet, the efficiency by which organic carbon is exported from surface waters during these blooms, as well as their contribution to carbon sequestration, remain poorly constrained. Here, we present an unprecedented number of measurements of sinking export fluxes (particulate organic carbon, POC; and biogenic silica, bSi) collected in the central Labrador Sea during a 2-week-long process study that observed the decline of a historically large PhaeocystisPhaeocystis± 5 mmol C m−2 d−1). Nevertheless, evidence of shallow POC flux remineralization combined with the fact that POC fluxes in the bloom were not higher than in a region sampled outside of the bloom (average of 13 ± 3 mmol C m−2 d−1) suggested a limited role of Phaeocystis> 51 µm) particles collected using large volume pumps presented relatively low bSi 
Mapping of soil organic carbon (SOC) is usually restricted to the top 100 cm of soils due to the limited penetration depth of standard soil sampling methods. This has resulted in current models underestimating SOC due to the unexplored deep carbon stocks. Moreover, standard methods only offer punctual data relying on interpolation to investigate extensive areas. We demonstrate here that subsurface 2D images of the complex electrical conductivity (CC) can delineate the presence and geometry of SOC reaching a depth of a few tens of meters below the surface. We show that an increase in the polarization effect at low frequencies (< 5 Hz) is linearly related to high concentrations of SOC. We present measurements from a catchment with silty loam soils, where the geometry of a deep carbon stock (between 4 and 6 m depth) was identified by CC images, and validated through laboratory analysis of soil samples.
Nitrogen availability constrains terrestrial carbon uptake and storage, yet large uncertainties remain in the magnitude of the effect, because the interactions of the carbon and nitrogen (N) dynamics are challenging to observe in undisturbed ecosystems at relevant timescales. Long-term experiments with 15N15N15N15N15N15N15N15N>90 %), and that this retention persisted over multi-decadal timescales. This study shows that explicit inclusion of isotopic tracers allows for a more thorough evaluation of carbon-nitrogen turnover and dynamics and thereby can contribute to reduce uncertainties in modelling nitrogen cycling and constraints in terrestrial ecosystems.
Coral communities in Hong Kong persist under a range of local stressors, including strong subtropical seasonality, chronic low light, and high turbidity, resulting in patchy, compositionally constrained communities relative to typical tropical reef systems. These challenging environmental conditions provide an opportunity to better understand how coral ecosystems may respond to changing ocean conditions in the future. Here, we used in-situ sensors to quantify high-resolution, community-scale net ecosystem production (NEP, organic carbon cycling) at three sites across a marine environmental gradient around Hong Kong. These communities were net respiring (negative NEP) across the gradient in both the wet (
This study systematically evaluated the contribution of UAV LiDAR structural features such as crop height (CH) and multi-layer gap fraction (GF) and the amplitude of the returning signal represented by normalized intensity (INT), together with multispectral (MS) and thermal infrared (TIR) observations for aboveground biomass (AGB) estimation in winter wheat using a common artificial neural network (ANN) framework. Among the evaluated single sensor approaches, LiDAR features consistently provided the strongest performance, demonstrating the complementary value of crop height, vertically distributed canopy density, and normalized LiDAR intensity for characterizing canopy structure and within-canopy variability. Multi-layer GF improved AGB estimation relative to conventional ground-based GF approaches, highlighting the importance of incorporating the vertical distribution of canopy density. Multi-sensor fusion produced only modest additional improvements, indicating limited benefits relative to the increased acquisition and processing requirements. Temporal analysis showed that structural LiDAR features were most informative during early crop development, whereas normalized intensity, spectral reflectance, and thermal observations became increasingly valuable during canopy maturation and senescence. Comparisons with destructively measured plant area index (PAI), leaf area index (LAI), green leaf area index (GLAI), and green fraction of LAI further demonstrated that normalized LiDAR intensity (903 nm) was more closely associated with green canopy components than purely structural LiDAR metrics. Overall, the results demonstrate that fully exploiting both the structural and spectral information contained within LiDAR observations can substantially improve UAV-based biomass estimation, while multispectral and thermal observations provide complementary information whose contribution varies with crop development and monitoring objectives.
Most emissions scenarios consistent with limiting warming to well below 2 °C above pre-industrial levels rely on carbon dioxide removal (CDR) to balance residual positive emissions or achieve net-negative emissions. While carbon cycle and climate metrics are well quantified for positive CO222222222
Hemiboreal forests bridge boreal and temperate biomes by combining functional and compositional features of both and playing a key role in regional carbon and water cycling. Water (WUE), carbon (CUE), and light (LUE) use efficiencies provide integrative indicators of how effectively ecosystems convert available resources into carbon uptake, yet their long-term dynamics and controlling factors remain poorly explained in hemiboreal forests. We analysed nine consecutive growing seasons (2016–2024) of eddy covariance measurements from an old upland hemiboreal coniferous forest in southern Estonia to quantify WUE, CUE, and LUE and to identify their controls at daily and growing-season scales and along a standardized precipitation-evapotranspiration index (SPEI) defined hydroclimatic gradient.Growing-season air temperature and vapour pressure deficit (VPD) increased over the study period. Despite this trend, WUE remained generally stable across years, with only one deviating growing season (2022) linked to intensified carbon uptake over a shorter season length. In contrast, CUE exhibited pronounced variability among growing seasons, driven primarily by changes in net ecosystem production and respiration dynamics. LUE was remarkably stable and showed no indication of age-related decline.At the daily scale, VPD controlled WUE and LUE, whereas photosynthetically active radiation exerted dominant control over CUE. Along the hydrometeorological gradient, all three resource use efficiencies responded non-linearly, but WUE and LUE remained generally stable, while CUE was the most variable metric and reflected shifts in the balance between carbon uptake and respiratory losses.Together, these results reveal differentiated sensitivities of ecosystem efficiencies to atmospheric drying and identify CUE as the most responsive indicator of hydroclimatic variability. Our findings provide new insight into the functional stability and potential thresholds of hemiboreal coniferous forests undergoing climate change.
Understanding the impact of ongoing global change on plant communities requires long-term quantitative reconstructions of past vegetation dynamics. Fossil pollen records offer one of the most powerful tools to reconstruct past landscapes, yet for their accurate interpretation it is important to take into account the differential pollen productivity of plant taxa. For southern Europe, and particularly for the Iberian Peninsula, estimates of pollen productivity remain scarce, limiting our ability to refine palaeoecological reconstructions.Here we present the first relative pollen productivity estimates (RPPs) for 21 common taxa in continental Spain. For that purpose, we used 1113 modern pollen samples from our own surveys and the Eurasian Modern Pollen Database (EMPD2), and vegetation data from the Spanish Forestry Map (MFE) and the Iberian and Macaronesian Vegetation Information System (SIVIM). RPPs were derived by applying an optimisation algorithm with the REVEALS model (REgional VEgetation Estimates from Large Sites). To test the reliability of our RPPs, we validated 8 arboreal taxa in 27 present-day coretops across Spain. We also compared the obtained RPPs with different studies across Europe, using a bias-free comparison framework.Our findings indicate that the dominant arboreal taxa (Pinus, evergreen and deciduous Quercus) are high pollen producers, whereas temperate forest, shrub and herbaceous taxa generally yielded medium to low estimates of pollen productivity. Validation of arboreal taxa from present-day coretopsThis study calculates, validates and compares the first RPPs in the Western Mediterranean, highlighting the value of quantitative palaeoecological data for Holocene landscape reconstructions. The findings of this paper would support that the Iberian Peninsula could have been home to a heterogeneous mosaic of open areas, conifers and broadleaf trees, offering new frameworks to improve both palaeoecological reconstructions and contemporary forest management strategies. Note: nomenclature and authority of the taxa in this paper were selected according to Flora Iberica (Castroviejo, 1986–2012).
High Latitude (HL) landscape fires are an important source of greenhouse gases and aerosols, with growing significance under rapid anthropogenic climate change-induced warming. Current fire emission inventories are mostly “bottom-up” in nature; combining, or relying on linear regressions between, satellite remote sensing data and process-based model outputs. However, these methods rely on uncertainties surrounding fuel load and combustion completeness. Here, we adapt the “top-down” Fire Radiative Energy Emission (FREM) approach for HL fires (HLFREM), linking Fire Radiative Energy (FRE) directly to emissions via coefficients derived solely from satellite observations. We derive biome-specific emission coefficients by combining Fire Radiative Power (FRP) from GFAS v1.4 with TROPOMI Total Column Carbon Monoxide plume observations, for the HL's four most fire-prone biomes; Deciduous and Evergreen Needleleaf Forests, Grasslands, and Shrublands. By applying these coefficients to daily GFAS v1.2 FRE totals (2003–2024), we estimate CO and total carbon emissions across the HL using HLFREM. HLFREM-derived CO emissions were found to be in good temporal and spatial agreement, but smaller in emission totals than other widely used inventories (GFAS v1.2 and GFEDv4.1s) in forested biomes, as well as with the MODIS-based FEER approach, with annual average differences of 54 % to 62 % smaller for Deciduous Needleleaf Forests, and 59 % to 70 % smaller for Evergreen Needleleaf forests. For Shrublands and Grassland biomes, HLFREM estimates are 65 %–75 % and 71 %–85 % lower respectively. Total carbon emissions, using Emission Factors, were found to show consistent patterns with CO across all biomes.
Eastern Boundary Upwelling Systems (EBUS) contribute disproportionately to global marine productivity and fisheries, yet their response to climate change remains poorly understood. Given the essential ecosystem services they support, improving projections of future EBUS dynamics is critical. Here we analyze projections of Net Primary Production (NPP) and its driving mechanisms using Earth System Models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Across the four major EBUS, twenty-first century NPP projections exhibit larger model uncertainty than scenario uncertainty, with limited confidence in the direction of future trends under different scenarios. This uncertainty partially results from compensating positive and negative NPP anomalies within individual systems, with consistent multi-model responses only emerging at subsystem scales. Although, consistent with most past studies, changes in upwelling-favorable winds are an important driver of the EBUS NPP response to climate change, they cannot fully explain projected responses. In the equatorward sectors of the Canary and Benguela systems, as well as in the historically most productive area of the California system (regions encapsulating 25 % of total EBUS area) a weakening of alongshore wind stress reduces upwelling intensity, nutrient supply to the euphotic zone and consequently NPP. However, in the remaining 75 % of EBUS extent, additional mechanisms are required to explain projected changes. These include upwelling anomalies induced by geostrophic transport and wind-stress curl, enhanced stratification, and changes in subsurface nutrient reservoirs, highlighting the complex and locally-specific response of EBUS productivity to climate change.
Nitrogen fluxes across the sediment-water interface and nitrogen removal from sediments are essential components of nitrogen cycle in semi-enclosed inland seas. However, the difficulty in observational sampling hinders continuous data availability that is necessary to understand their seasonal variations and underlying mechanisms. To address this issue, we developed a one-dimensional sediment nitrogen-cycle model and used sensitivity experiments to quantify the relative roles of environmental and biogeochemical drivers. Model results indicate that 48 %%
Although boreal peatlands play a critical role in the global carbon cycle, their year-round carbon dioxide (CO2) dynamics, and particularly the contribution of the non-growing season, remain poorly constrained in annual balance estimates. Using 17 years (2005–2021) of eddy covariance measurements from a fen in southern Finland, we first quantified the magnitude, timing, and interannual variability of CO2± 27 d), ranging from mid-September to late April, and offset 57 % (±33 %) of the subsequent productive season's CO22222−2, offsetting 38 % of the following productive season's CO2222
Microbial communities within biofilms are widely recognised as important contributors to ecological food webs and elemental cycles within stream systems. Yet, little is known about how these biofilm communities respond compositionally to storm-event-driven changes in dissolved organic carbon (DOC) characteristics. Alpine headwater peatland-draining streams offer a unique opportunity to investigate this response as these systems are known to export high loads of DOC during storm events, with little further upstream input. This study investigated how sub-alpine peatland-draining stream biofilm composition changed in response to storm-event-driven pulses of DOC. It was found that during the peak of each DOC pulse, the composition of DOC changed to include increased contributions of organic acids, protein-like substances and microbially derived DOC. Despite this change in DOC composition, the composition of most biofilm microbial communities did not significantly shift following each pulse; rather, differences in biofilm community composition appeared to be more closely linked to peatland stream site. The findings of this study suggest biofilm microbial communities maintain compositional stability following short-term rapid changes in stream water chemistry, and that site-specific environmental factors may be more important in determining biofilm microbial community composition in sub-alpine headwater peatland-draining streams.
Larval dispersal is a fundamental process linking marine populations and shaping individual fitness and population connectivity, making its quantification essential for understanding recruitment dynamics in fisheries. However, larval dispersal of the commercially and ecologically important Japanese anchovy (Engraulis japonicus), one of the most abundant pelagic fishes in the China Seas, remains poorly understood. Here, we applied 1D and 2D dispersal kernels to quantify larval dispersal outputs from previously published Lagrangian particle-tracking simulations, in which particles were released from seven spawning grounds across the China Seas during April–August (1987–2004) and tracked for 30–60 d. We evaluated the relative influences of spawning ground, spawning month and year, and larval travel duration, on dispersal patterns and connectivity. Larval settlement was concentrated in the Bohai Sea, the northern Yellow Sea and along the southern coast of the Shandong Peninsula, with peak densities near 39° N, identifying these regions as major nursery areas. A Weibull 1D dispersal kernel best described larval dispersal-distance distribution, with modal dispersal distances from 42.67 to 153.23 km among spawning grounds. Of the factors examined, spawning ground was the dominant driver of dispersal and connectivity, explaining 31 % of the variance. Larvae from Changjiang Estuary spawning ground dispersed more broadly to the Yellow Sea, Sea of Japan and the northwestern Pacific, whereas larvae from other grounds were largely retained within the China Seas, suggesting the Changjiang Estuary may provide a potential pathway for connectivity among regional populations. Dispersal patterns exhibited strong seasonal shifts, with enhanced eastward and northward export in spring–early summer and increased retention in late summer. Increasing larval travel duration promoted directional long-range transport while reducing occupied area, local retention and self-recruitment, indicating that longer dispersal does not imply broader spatial occupation. Pelagic larval duration captured mean dispersal trends but was a poor predictor of individual dispersal outcomes. Overall, these findings provide a quantitative framework for understanding larval dispersal dynamics and may help inform fisheries management of Japanese anchovy.
Europe’s forests store vast amounts of carbon, but climate-driven disturbances are becoming more frequent. By combining satellite records with information on forest age and structure, we show that recent disturbances increasingly affect the oldest and most carbon-rich forests, particularly spruce forests in Central Europe. This emerging pattern puts long-accumulated carbon at risk and may reduce the long-term climate benefits provided by Europe’s forests.
Europe's forests store nearly 40 PgC and provide a critical carbon sink of ∼ 0.2 PgC yr−1, yet climate-sensitive disturbances increasingly threaten this capacity. Although disturbance rates from windthrow and bark beetle outbreaks have risen in recent decades, it remains unclear whether these events increasingly affect the oldest and largest trees, which store a disproportionate share of carbon. Focusing on bark beetle outbreaks and windthrow, the dominant natural disturbance agents in temperate and boreal European forests, we combine three decades of satellite-derived disturbance maps with spatially explicit data on forest age, biomass, and species composition to reveal patterns of structural selectivity across Europe. We show that natural disturbances have shifted toward older, carbon-rich forest patches, with disturbed forest area >60= 1.1). As a result, biomass losses from natural disturbances in spruce forests increased fivefold between the early (2011–2016) and recent (2017–2023) periods, outpacing the expansion of the disturbed area. Trend-based projections indicate that, if current patterns of structural selectivity persist, natural disturbances could expose biomass carbon stocks equivalent to approximately 20 % of Europe's contemporary forest carbon sink by 2040 (∼ 0.05 PgC yr−1∼ 0.8 PgC cumulative). Our findings reveal a previously unquantified structural susceptibility: climate-sensitive disturbances increasingly affect forest structures with high per-hectare carbon stocks, amplifying disturbance-related carbon susceptibility and weakening the long-term effectiveness of Europe's forest carbon sink. Adaptive management strategies that promote structural and compositional diversification in high-risk regions will be