Wetlands are a critical component of the global biogeochemical cycle and have great potential for carbon sequestration under the changing climate. However, previous studies have mainly focused on the dynamics of soil organic carbon while paying little attention to the vegetation carbon storage in wetlands. Poyang Lake is the largest freshwater lake in China, where intra-annual and inter-annual variations in water levels significantly affect the vegetation carbon storage in the floodplain wetland. Therefore, we assessed the seasonal distribution and carbon storage of six typical plant communities (Arundinella hirta, Carex cinerascens, Miscanthus lutarioriparius, Persicaria hydropiper, Phalaris arundinacea, and Phragmites australis) in Poyang Lake wetlands from 2019 to 2024 based on field surveys, the literature, and remote sensing data. Then, we used 16 preseason meteorological and hydrological variables for two growing seasons to investigate the impacts of environmental factors on vegetation carbon storage based on four correlation and regression methods (including Pearson and partial correlation, ridge, and elastic net regression). The results show that the C. cinerascens community was the most dominant contributor to vegetation carbon storage, occupying 12.68% to 44.22% of the Poyang Lake wetland area. The vegetation carbon storage in the Poyang Lake wetland was significantly (p < 0.01) higher in spring (87.75 × 104 t to 239.10 × 104 t) than in autumn (77.32 × 104 t to 154.78 × 104 t). Water body area emerged as a key explanatory factor, as it directly constrains the spatial extent available for vegetation colonization and growth by alternating inundation and exposure. In addition, an earlier start or end to floods could both enhance vegetation carbon storage in spring or autumn. However, preseason precipitation and temperature are negative to carbon storage in spring but exhibited opposite effects in autumn. These results assessed the seasonal dynamics of dominant vegetation communities and helped understand the response of the wetland carbon cycle under the changing climate.

Soil organic carbon (SOC) dynamics along hillslopes are influenced by vegetation and topography. However, the detailed contributions of vegetation cover patterns and topographic traits to the spatial variation in soil carbon sequestration resulting from SOC transport, decomposition, and deposition remain poorly understood. This study investigated the spatial variation of soil orgainc carbon delta C-13 along three hillslope transects with differed vegetation cover patterns (pure forest, a forest-grass combination, and pure grass) to evaluate the contribution of vegetation cover pattern and topographic traits (Topographic Wetness Index, TWI; Topographic Position Index, TPI). Soil samples were collected from depths of 0-50 cm at sites along the three transects. The results indicated that soil orgainc carbon delta C-13 increased nonlinearly with soil depth across all vegetation cover patterns. Forestland generally exhibited lower soil orgainc carbon delta C-13 values than the forest-grass combination and grassland, accompanied by greater vertical variation (60.9%). The soil depth threshold at which the soil orgainc carbon delta C-13 value approached a stable value differed among the three transects (forest: 15.2 cm, forest-grass: 15.4 cm, and grass: 15.6 cm). Along the downslope direction, soil orgainc carbon delta C-13 of the surface soil (0-5 cm) in forest land generally decreased, whereas it first increased and then decreased in forest-grass combination and grassland. In deeper soil layers (>5 cm), however, soil orgainc carbon delta C-13 showed an overall increasing trend from hilltop to toe slope. Vegetation cover primarily regulates variation of soil orgainc carbon delta C-13 in surface soils, while topographic traits exert a strong influence on subsurface soil. These results indicate that vegetation and topography jointly regulate the spatial variations of soil orgainc carbon delta C-13 through SOC input, transport, decomposition, and redistribution. This study highlights the importance of considering topographic heterogeneity and vegetation patterns for enhancing carbon sequestration in semi-arid ecosystems.

Waterbird diversity and its landscape drivers along the YRB remain poorly understood across seasons and spatial scales. Waterbird observations from five synchronous surveys conducted between October 2022 and October 2023 were integrated into four seasonal datasets and combined with land-use data to examine diversity–landscape associations across spatial scales from 5 to 50 km. Waterbird diversity was significantly lower in winter than in spring and summer, and lower in the lower reaches compared with the middle and upper reaches. Relationships between landscape structure and waterbird diversity varied by season, scale, and region. Spring diversity was positively linked to PC3 derived from principal component analysis at 10 km (F = 9.273, p < 0.01, estimate = 0.096), implying a beneficial role of grassland–cropland heterogeneity. Summer effects indicated that grassland area, dominance, and impervious-surface aggregation may shape breeding-season diversity, with significant PC3 × region and PC2 × region interactions at 5 and 10 km, respectively (F = 3.951, p < 0.05; F = 3.040, p < 0.05). Autumn relationships showed a positive PC1 effect at 5 km (F = 12.814, p < 0.01, estimate = 0.184) and a significant region × PCA interaction at 50 km (F = 2.961, p < 0.01), suggesting that greater grassland extent and dominance may provide a favorable landscape context for migratory waterbirds. Winter at fine-scale showed that greater grassland availability provided a favorable local context, whereas more complex wetland and barren-land structures corresponded to lower diversity, as supported by contrasting principal component effects at 5 km (PC1: F = 9.143, p < 0.01, estimate = 0.169; PC2: F = 4.796, p < 0.05, estimate = −0.159; PC3: F = 6.266, p < 0.05, estimate = −0.068), whereas broad-scale gradients reflected wetland shape variability and regional landscape heterogeneity. These findings underscore the need for season-specific, multi-scale habitat management to conserve waterbirds across the YRB.

Effective conservation relies on robust assessments; however, the lack of waterbird data in the Yellow River Basin (YRB) has led to an underestimation of key habitat significance. This study addressed this gap by evaluating YRB wetland conservation importance using waterbirds as indicators and applying Ramsar, Important Bird Areas (IBA), and East Asian-Australasian Flyway (EAAF) criteria. We integrated coordinated surveys with citizen science data, creating a framework that tackles data deficiencies along the under-monitored Central Asian Flyway (CAF). Our analysis identified 75 priority wetlands, supporting 15 threatened species and 49 exceeding global/flyway 1% thresholds, highlighting the basin's biodiversity. We observed strong seasonal habitat use, with high-altitude wetlands vital for breeding and migration, and the Yellow River Delta providing year-round refuge. This research also provided data to refine Baer's Pochard population estimates. Alarmingly, one-third of the identified priority areas, primarily rivers and lakes, remain unprotected. To address this, we recommend systematic surveys, enhanced protected areas, OECMs, and targeted wetland restoration. This study underscores the YRB's role in regional conservation and provides essential data for adaptive management, particularly emphasizing the CAF's importance.

Global change, particularly extreme droughts, threatens critical migratory bird habitats like Poyang Lake, a key wintering ground on the East Asian-Australasian Flyway, forcing waterbirds such as geese to increasingly utilize artificial wetlands. Using satellite tracking, ground surveys, and remote sensing, we assessed how wintering geese adjusted their habitat use during an extreme drought year compared to a normal year. Geese expanded their home ranges during drought, with the artificial wetland area composition increased from 1.90 +/- 1.84 km2 to 26.82 +/- 4.58 km2. Habitat use peaked in artificial wetlands during mid-winter, then declined in late winter as natural forage recovered. Diel patterns revealed species-specific strategies: Swan Geese (Anser cygnoides) maintained high day-night reliance on artificial wetlands, Bean Geese (A. fabalis) favored nocturnal use, and Greater White-fronted Geese (A. albifrons) showed minimal dependence, indicating greater ecological risks for the first two species. Vegetation indices confirmed a drought-driven decline and delayed regrowth in natural Carex meadows, closely matching habitat use shifts. These findings demonstrate behavioral plasticity in response to fluctuating resource availability but raise concerns that artificial wetlands, while acting as temporary refuges, may negatively affect waterbirds and lead to human-wildlife conflicts. Although we do not assess fitness consequences directly, our results highlight the potential for ecological mismatch under increasing hydrological variability. We recommend a joined-up effort by prioritizing natural wetland restoration via hydrological management and vegetation recovery, alongside strategic artificial wetlands management to mitigate human disturbances. This study provides essential guidance for adaptive wetland management and waterbird conservation in floodplain ecosystems facing climate change.

Interconnected habitats are essential for migratory species to complete their life cycles. Traditional habitat connectivity assessment methods often neglect temporal interactions, changes over time, as well as the heterogeneous ecological roles of internal habitat components. These limitations hinder the effectiveness of conservation efforts. In this study, we developed a spatiotemporal connectivity - component effects framework to assess habitat distribution, spatiotemporal connectivity, component-level contributions and generated spatially optimized conservation strategies for Swan Goose (Anser cygnoides) along the East Asian-Australasian Flyway. Our results reveal a projected 36%-46% reduction in suitable habitat for Swan Geese under future climate (2050 SSP126/245/585) scenarios compared with that in 2020. Habitat connectivity declined throughout the entire breeding migration continuum, and connectivity levels were generally highest during spring migration, followed by the breeding and wintering stages. Component analysis revealed that habitat connectivity is influenced more by direct linkages between habitat patches (52.4%-72.1%) and stepping stones (13.1%-27.2%) than by internal factors such as patch area (7.7%-24.4%). Under climate change, the contribution of direct connectivity is projected to decrease significantly by 22.0%-39.5%, and the contribution of stepping stones is expected to increase markedly by 26.6%-55.4%. We recommend prioritizing the conservation of high-connectivity habitats (including the middle-lower Yangtze River wetlands, the Yellow-Bohai Sea coastal wetlands, and the Mongolian Plateau wetlands) and key connectivity facilitators/stepping stones (the Hangzhou Bay coastal wetlands, the West Korea Bay coastal wetlands, and the Selenga River Basin wetlands). This adaptable methodology provides a scalable technical paradigm for enhancing global biodiversity conservation efforts for migratory species.

1. Floodplain wetlands such as Poyang Lake are increasingly shaped by hydrological extremes, yet the mechanisms linking hydrology to waterbirds' space use remain unclear. We aimed to quantify species-specific distribution, habitat selection and behavioural plasticity across contrasting hydrological conditions to inform conservation and wetland management. 2. We integrated satellite tracking of greater white-fronted goose (Anser albifrons), bean goose (A. fabalis) and swan goose (A. cygnoides) with remote sensing and a hydrological classification derived from long-term water levels and the SPEI. Individual winter home ranges and utilisation intensity were estimated, mapped, and linked to habitat types. Space-use metrics were compared across hydrological categories (normal, drought, extreme drought) to assess species-specific selection. 3. Species differed markedly amongst hydrological years. Greater white-fronted and bean geese had larger home ranges and higher mean utilisation intensity in drought and extreme drought years, whereas swan geese showed the opposite pattern. Hydrology strongly structured habitat selection: differences amongst habitat types were pronounced in normal and drought years but weakened under extreme drought. Fresh, sparse wet meadows dominated in normal and drought years; during extreme drought, use of mudflats and tall sedges increased, with parallel shifts in utilisation intensity. 4. Wintering geese adjusted home range size, utilisation intensity, and habitat preferences under extreme drought, demonstrating pronounced behavioural plasticity and hydrology-dependent space-use strategies. By elucidating species-specific mechanisms linking hydrology to habitat selection in a dynamic Ramsar wetland, this study advances habitat selection theory for floodplain systems and provides actionable guidance for conserving geese and managing Poyang Lake under increasing hydrological extremes.

To tackle the planetary environmental and climate crisis and meet the United Nations’ Sustainable Development Goals (SDGs), we must fully leverage the potential of Earth observations (EO). This involves integrating globally sourced data on the atmosphere, hydrosphere, cryosphere, lithosphere, along with ecological and socio-economic information. By harmonizing and integrating these diverse data sources, we can more effectively incorporate observational data into multi-scale modeling and artificial intelligence (AI) frameworks. This paper is based on discussions from the “Towards Global Earth Observatory” workshop held from May 8–10, 2023, organized by the World Meteorological Organization (WMO) and the Atmosphere and Climate Competence Center (ACCC), in collaboration with the Institute for Atmospheric and Earth System Research (INAR) at the University of Helsinki. The current state of EO and data repositories is fragmented, highlighting the need for a more integrated approach to establish a new global Ground-Based Earth Observatory (GGBEO). Here, we summarize the current status of selected in-situ and ground-based remote sensing observation systems and outline future actions and recommendations to meet scientific, societal, and economic needs. In addition, we identify key steps to create a coordinated and comprehensive GGBEO system that leverages existing investments, networks, and infrastructures. This system would integrate regional and global ground-based in situ and remote sensing systems, marine, and airborne observational data. An integrated approach should aim for seamless coordination, interoperable and harmonized data repositories, easily searchable and accessible data, and sustainable long-term funding.

Global environmental challenges like ecological drought demand cross-border collaboration and interoperable data. The Global Ecosystem Research Infrastructure (GERI) was founded to address this need, building relationships and establishing data sharing practices among six of the largest ecosystem research infrastructures in the world. Data harmonization is required to standardize and ingest data products from these infrastructures into a findable, accessible, interoperable, reusable (FAIR) global dataset. Harmonized global data can improve existing global climate models and inform environmental research studies. This poster presents a proof of concept for harmonizing ecological drought-related data products including air temperature, precipitation, soil moisture, soil temperature and soil texture starting with data from NEON (USA) and TERN (Australia). The process involved crosswalks for variable names and units, term mapping, and metadata standardization using controlled vocabularies and EML. We describe both technical and institutional challenges encountered in aligning data from diverse infrastructures, including differences in structure, granularity, and documentation. These lessons are shaping the development of scalable methods and shared practices as we expand the effort to include additional networks RIs. Looking ahead, we aim to broaden the scope of harmonization to additional ecological domains. This work will be led in part by GERI’s Early Career Researcher working group and pursued in collaboration with international initiatives like DroughtNet and the International Drought Experiment. These efforts mark progress toward a globally interoperable environmental data landscape in support of science, policy, and ecosystem resilience.

Submerged macrophytes like Vallisneria spinulosa S. Z. Yan play vital roles in aquatic ecosystems by stabilizing sediments, improving water quality, and providing habitat for organisms. However, their populations are declining globally due to environmental stressors like light limitation and bioturbation. This study examined how shading and bioturbation by Procambarus clarkii (Girard, 1852) and Carassius carassius (Linnaeus, 1758) influence V. spinulosa growth and reproduction. Severe shading (50

Wetland hydrological processes have a significant impact on wetland carbon storage.However,the mechanisms by which they affect biomass and carbon storage by regulating soil nutrient content and plant diversity remain underexplored.From June 4th,2018 to April 10th,2019,we conducted daily monitoring of daily water levels,plant diversity and dominance,aboveground and underground plant biomass,as well as soil content of 10 elements(carbon,nitrogen,phosphorus,potassium,sodium,calcium,magnesium,iron,manganese,and zinc)under different elevation gradients in the internationally significant Poyang Lake Wetland,resulting in the formation of a comprehensive dataset.The dataset consists of one Excel file with five sheets,covering plant directory,individual plant numbers,plant biomass,soil element content,and daily water levels for 21 sample plots across seven elevation gradients.The quality of dataset is mainly controlled and evaluated from the aspects of precise design of the plant survey scheme,fine collection of plant and soil samples,laboratory processing and data entry,and third-party calibration.This dataset can provide data support for revealing the process mechanisms among hydrology,soil nutrients,plant biomass,and soil carbon,as well as those between plant dominance,plant biomass soil carbon.It offers an in-depth understanding of how wetland hydrological processes influence vegetation growth and carbon sequestration by regulating nutrient enrichment,thereby laying a new foundation for understanding carbon-water coupling mechanisms.

Changes in migratory birds' habitats are important indicators of the health of global ecosystems. However, the habitat dynamics of the flagship swan species in China's major river basins and the adaptive strategies these species employ to respond to climate change have remained unclear. Using citizen science data, survey data, and species distribution models, we explored how three future climate scenarios for 2040-2060 affect habitat suitability for migratory swans in the Yellow River Basin. We also evaluated the role of protected areas (PAs) in mitigating the negative impacts of climate change. We found that (1) under current climate conditions, the Mute Swan (Cygnus olor), the Bewick's Swan (Cygnus columbianus bewickii), and the Whooper Swan (Cygnus cygnus) occupy substantial suitable habitats, with the Whooper Swan having the most extensive range. (2) the Mute Swan and the Bewick's Swan were predicted to experience the largest habitat loss under the high-emission scenario, while the Whooper Swan would benefit from climate change by gaining suitable habitat, especially under the medium-emission scenario. (3) PAs were most effective in mitigating the adverse effects of climate change on habitat suitability for the Mute Swan, followed by the Whooper Swan, with limited mitigating effect for the Bewick's Swan. These findings highlight the need for species-specific conservation strategies and the critical role of PAs in preserving habitat suitability under climate change.

Climate change and human activities have altered the hydrological patterns of Lake Poyang,leading to lower dry season water levels and extended dry periods.Additionally,extreme events such as the floods of 2020 and the prolonged droughts of 2022 and 2023 have occurred.These changes have significantly impacted the growth and reproduction of floodplain plants.This study in-vestigated the dominant floodplain plant,Carex cinerascens,examining five water level recession timing scenarios:30 days earlier,15 days earlier,normal,15 days later,and 30 days later.The study observed the plant's growth and reproductive responses.The results showed:(1)Water recession timing significantly affected the maximum height of Carex cinerascens.Earlier recession in-creased plant height,while later recession reduced it.The impact on aboveground biomass varied seasonally.In autumn,delayed recession significantly decreased aboveground biomass,while in spring,there was no significant effect.Both spring and autumn un-derground biomass decreased with delayed recession,affecting biomass distribution between seasons.(2)Water level recession timing also significantly influenced vegetative reproduction in the autumn growth stage.Earlier recession increased the number of tillers and the quantity and length of spacers,while delayed recession inhibited tillering and reduced spacers'quantity and length.Both earlier and delayed recession affected the number of flowering stems and inflorescences in spring,but the impact was smaller with earlier recession compared to delayed recession.These findings provide a theoretical basis for the conservation and management of dominant wetland plants under changing hydrological conditions.

BACKGROUND:The degradation and loss of critical nodes in the East Asian-Australasian Flyway (EAAF) migration network could have implications for the migration of shorebirds. The conservation of critical nodes along the EAAF is important for maintaining the stability of migratory networks. However, identifying these nodes remains a major challenge. METHODS:We used a network method that integrates GPS tracking data and remote sensing data to identify critical nodes for three shorebird species (Black-tailed Godwit (Limosa limosa), Eurasian Curlew (Numenius arquata), and Pied Avocet (Recurvirostra avosetta)) in migratory networks along the EAAF and priority conservation areas to facilitate the development of conservation and management plans. RESULTS:A total of 111, 37, and 81 nodes in the migratory networks were identified for the Black-tailed Godwit, Eurasian Curlew, and Pied Avocet, respectively; these included 25, 13, and 16 critical nodes, respectively. Node importance (node betweenness) was higher in the migration period than in the breeding and wintering periods. Habitat loss was observed in most stopover nodes. A total of 23 unprotected critical nodes were identified as priority conservation areas. CONCLUSIONS:Habitat loss was observed in most of the unprotected critical nodes in stopover regions for all three species. The inclusion of these sites such as Haoyao sumu forest farm and Tianjin coast, into flyway site networks (the East Asian-Australasian Flyway Partnership (EAAFP)) should be prioritized, and the habitat quality of nearby alternative nodes should be improved. Future studies should focus on developing new node indexes that integrate ecological variables with each node's role in maintaining network connectivity using data from a larger number of tracked individuals and birdwatching data. Such studies could help identify currently unknown regions with critical habitats.

Despite the influence of drought on ecosystem functions and human well-being, there are significant uncertainties in our understanding of the impacts of drought for ecosystems and humanity. Over the past decade, large Environmental Research Infrastructures (ERIs) have been implemented around the world to advance our understanding in the responses of the biosphere to environmental change. These emergent ERIs now provide a unique opportunity to advance our understanding of ecological processes, such as drought, across continents, decades, and disciplinary boundaries. Against this backdrop, 6 ERIs (SAEON/South Africa, TERN/Australia, CERN/China, NEON/USA, ICOS/Europe, eLTER/Europe) have established an international network-to-network collaboration – the Global Ecosystem Research Infrastructure (GERI). To date, GERI activities have focused on garnering support, establishing baseline pathways for communications across continents and cultures and an initial mapping of each ERI’s data availability to facilitate future research. With recent funding from a U.S. National Science Foundation AccelNet award, GERI is poised to begin harmonizing key drought-related data. Working with stakeholder partners in the The Drought-Net Research Coordination Network’s and International Drought Experiment, we have identified key baseline data products for harmonization capable of driving new discoveries across continents. These data include soil moisture, precipitation, soil texture, and aboveground biomass, water balance, etc. As we advance this project, these harmonized data will be open, findable, searchable, and accessible, and made available to the broader community for research and discovery and stakeholder networks including the International Drought- Network to test and model. Data contributions from these new and emerging networks will be encouraged and streamlined through accessible metadata and standards. Lessons learned from the intersection of global drought data will be applied to the expanding set of environmental data collected by research networks around the world.

The population of East Asian geese along migration routes is declining. Accurate understanding of the spatial distribution of wintering geese and estimates of their population numbers are vital for their conservation. Based on satellite tracking data, the migration timing and spatial distribution of geese in Poyang Lake were studied by using time series and home range analysis. We propose a method for estimating goose populations to address the population underestimation in current ground surveys. We found that the utilization intensity of geese is higher within the Protected area than outside, and during the wintering period, spatial overlap in their distributions is evident. This is especially the case in mid-winter, when the overlap area reaches 257.84 km2. There are missing areas in existing ground surveys, resulting in underestimation of the numbers of Greater White-fronted Goose, Bean Goose and Swan Goose by 13,196, 6157 and 3191, respectively. A reevaluation of the numbers using integrated satellite tracking and ground survey data, indicates the high level of importance of Poyang Lake for the protection of East Asian geese, with the numbers of Greater White-fronted Goose, Bean Goose, and Swan Goose wintering there constituting 56.94

Migratory flyways sustain waterbird populations by linking critical habitats across their annual cycle. However, stage-specific impacts of climate change on these habitats remain poorly understood. We integrated species distribution models with annual migration data from 30 Greater White-fronted Geese (Anser albifrons frontalis) to assess changes in habitat suitability, distributional shifts, and suitability fluctuations across breeding, stopover, and wintering stages under mid-century (2040–2060) climate scenarios. Suitability fluctuations were quantified as the coefficient of variation (CV) in habitat suitability between current and future projections. Projected habitat responses varied markedly across stages: breeding areas contracted by 29.9%, wintering areas expanded by 62.7%, and stopover sites showed minimal net change. Centroids of all habitats are projected to shift northward by mean distances of 125–492 km under future climate scenarios. Breeding habitats exhibited the greatest suitability fluctuations (CV=30–45; ~50% area affected under SSP585), followed by stopover and wintering grounds (CV ≈ 11), with 35.8% and 23.3% of their areas falling within high-fluctuation zones. These findings highlight the urgent need to prioritize breeding habitats, implement stage-specific conservation strategies, and enhance international cooperation to ensure the protection of waterbirds along the East Asian Flyway.

Hydrological connectivity is considered a crucial factor in maintaining the biodiversity of wetland waterbirds, but quantifying this relationship remains challenging. This study uses synthetic aperture radar (Sentinel-1 SAR) to efficiently and cost-effectively quantify the number of surface hydrological connectivity days in large floodplain wetlands. Based on waterbird occurrence data from citizen science platforms and The Maximum Entropy Model (MaxEnt) we simulated habitat suitability for different waterbird families in Poyang Lake. Through a coupled analysis of surface hydrological connectivity and habitat suitability, we found that habitat suitability generally increased with connectivity days up to approximately 36-78 days and then declined, except under extreme hydrological conditions. Extreme floods and droughts were associated with reduced habitat suitability. During normal years, habitat suitability showed little difference between controlled sub-lakes and connected sublakes. However, in years of flood or drought, the habitat suitability of controlled sub-lakes exceeded that of connected sub-lakes by more than 0.15, indicating that moderate hydrological regulation can mitigate the negative impacts of extreme events on waterbird habitats. This study provides a scientific basis for hydrological management strategies in response to the intensified frequency of extreme hydrological events, aiming to enhance wetland resilience under climate warming.