Search

The Cheadle Center at UCSB manages more than 340 acres of open space between Ellwood Mesa and Goleta Slough, carrying out ecological restoration, research, and education projects at these sites. Characterized by a rich complex of oak woodland, coastal sage scrub, grassland, and wetland ecosystems, the area is known for its relatively high level of biodiversity. The Cheadle Center’s project sites and management areas serve to protect and strengthen the region’s ecology and ecosystems through habitat conservation, upland restoration, wetland creation and enhancement, and the implementation of sustainable stormwater management solutions. Through careful integration with local watersheds and surrounding natural areas, The Cheadle Center's management areas provide an important corridor and refuge for wildlife, ensure the long term preservation of the region's natural resources, and serve as outdoor classrooms, research sites, and recreational areas for the campus community and the public. This archived version of the March 2024 newsletter includes updates on the Ellwood Bioblitz, Spring weeding efforts, Wildflowers, Rare Plants, and the Ocean Meadows Housing Project. The feature story focuses on the presetations and research conducted at Cheadle Center management areas. Community photos include Lesser Scaup (Aythya affinis), Red-breasted Merganser (Mergus serrator), Caspian Tern (Hydroprogne caspia), and more!

The Cheadle Center at UCSB manages more than 340 acres of open space between Ellwood Mesa and Goleta Slough, carrying out ecological restoration, research, and education projects at these sites. Characterized by a rich complex of oak woodland, coastal sage scrub, grassland, and wetland ecosystems, the area is known for its relatively high level of biodiversity. The Cheadle Center’s project sites and management areas serve to protect and strengthen the region’s ecology and ecosystems through habitat conservation, upland restoration, wetland creation and enhancement, and the implementation of sustainable stormwater management solutions. Through careful integration with local watersheds and surrounding natural areas, The Cheadle Center's management areas provide an important corridor and refuge for wildlife, ensure the long term preservation of the region's natural resources, and serve as outdoor classrooms, research sites, and recreational areas for the campus community and the public. This archived version of the March 2024 newsletter includes updates on the NCOS Mesa burn area and Ventura Marsh Milk Vetch. The feature story focuses on the Sierra Madre restoration area. Community photos include Bonaparte's Gull (Chroicocephalus philadelphia), American Bittern (Botaurus lentiginosus), Orange-crowned Warbler (Vermivora celata) and more!

Climate change and invasive species represent two intertwined global environmental challenges profoundly affecting freshwater ecosystems. This study uses Ecological Niche Modeling along with risk screening to delve into the preferences and potential distribution of Potamopyrgus antipodarum, an invasive species, in relation to climate zones and habitat types, shedding light on the critical importance of coastal wetlands and high soil organic carbon content in shaping habitat suitability. Our findings underscore that P. antipodarum exhibits a distinct affinity for cool temperate, moist climates, as well as temperate floodplain rivers, wetlands, and coastal areas. Notably, coastal wetlands, endowed with elevated soil organic carbon levels, emerged as pivotal habitats for this species. Projections indicated a significant expansion in North America, potentially extending into South America. Türkiye reveals an intriguing alignment between its habitat and the natural distribution areas of P. antipodarum, presenting potential for habitat contraction while still retaining a broader range compared to other regions. These potential expansions were predominantly driven by climate suitability, playing a pivotal role in the invasiveness of P. antipodarum, with anticipated future climate regimes exerting substantial influence on its dispersal capabilities. [ABSTRACT FROM AUTHOR]

Marsh and mangrove forest habitats are productive at capturing and storing carbon, thus actions to protect and create coastal blue carbon sinks could help mitigate global warming. Dredged material is often used to create coastal habitats and evaluating the carbon impact of placement alternatives (PA) could help inform restoration and climate policies. Output from a Delft3D‐FM morphodynamics and hydrodynamics model informed a Coastal Wetlands Carbon Model at years 2020, 2025, 2030, and 2050. Three model simulations were used and included (1) no restoration (PA1), (2) restoration dominated with mangroves (PA2), and (3) restoration dominated with marshes (PA3) at a different location. Habitats of brackish marsh, saline marsh, mangrove forest, and saline open water that surround Port Fourchon, Louisiana, U.S.A., were evaluated to estimate the net greenhouse gas (GHG) flux of the study area with and without restoration. In years 2020 and 2025, the study area was estimated to be a net GHG sink (−1.1 ± 0.2 MMT CO2e) with or without mangrove and marsh‐dominated restoration. At years 2030 and 2050, even with habitat loss due to sea‐level rise, the study area for all simulations was projected to remain a net GHG sink. At year 2050, +0.1 ± 0.04 MMT CO2e could be avoided with restoration. At the restoration project scale, mangrove‐dominated restoration (PA2) had net GHG sinks (−0.07 to −0.09 MMT CO2e) near the marsh‐dominated restoration (PA3, −0.09 to −0.13 MMT CO2e). Thus, these modeled results could help inform future restoration planning and climate policies. [ABSTRACT FROM AUTHOR]

Large grazers modify vegetated ecosystems and are increasingly viewed as keystone species in trophic rewilding schemes. Yet, as their ecosystem influences are context‐dependent, a crucial challenge is identifying where grazers sustain, versus undermine, important ecosystem properties and their resilience. Previous work in diverse European saltmarshes found that, despite changing plant and invertebrate community structure, grazers do not suppress below‐ground properties, including soil organic carbon (SOC). We hypothesised that, in contrast, eastern US saltmarshes would be sensitive to large grazers as extensive areas are dominated by a single grass, Spartina alterniflora. We predicted that grazers would reduce above‐ and below‐ground Spartina biomass, suppress invertebrate densities, shift soil texture and ultimately reduce SOC concentration. We tested our hypotheses using a replicated 51‐month large grazer (horse) exclusion experiment in Georgia, coupled with observations of 14 long‐term grazed sites, spanning ~1000 km of the eastern US coast. Grazer exclusion quickly led to increased Spartina height, cover and flowering, and increased snail density. Changes in vegetation structure were reflected in modified soil texture (reduced sand, increased clay) and elevated root biomass, yet we found no response of SOC. Large grazer exclusion also reduced drought‐associated vegetation die‐off. We also observed vegetation shifts in sites along the eastern US seaboard where grazing has occurred for hundreds of years. Unlike in the exclusion experiment, long‐term grazing was associated with reduced SOC. A structural equation model implicated grazing by revealing reduced stem height as a key driver of reduced soil organic carbon. Synthesis: These results illustrate the context dependency of large grazer impacts on ecosystem properties in coastal wetlands. In contrast to well‐studied European marshes, eastern US marshes are dominated and structured by a single foundational grass species resulting in vegetation and soil properties being more sensitive to grazing. Coastal systems characterised by a single foundation species might be inherently vulnerable to large grazers and lack resilience in the face of other disturbances, underlining that frameworks to explain and predict large grazer impacts must account for geographic variation in ecosystem structure. [ABSTRACT FROM AUTHOR]

Yancheng coastal wetland, the largest coastal wetland in the west coast of the Pacific Ocean and the margin of the Asian continent, has significant environmental, economic and social effects on local human beings. The extensive contamination and potential risk of quinolone antibiotics (QNs) on local aquaculture and human health are still not clear until now. In this study, 52 surface sediment samples were collected to investigate the contamination status and polluted sources, and evaluate ecological risks of QNs in the south of Yancheng coastal wetland. The total contents of QNs ranged from 0.33 to 21.60 ng/g dw (mean value of 4.51 ng/g dw), following the detection frequencies of QNs ranging from 19.23 to 94.23%. The highest content of QNs occurred around an aquaculture pond dominated by flumequine. The total organic carbon contents of sediment were positively correlated with sarafloxacin and lomefloxacin (p < 0.05), indicating the enhanced absorption of these QNs onto sediments. Partial QNs, such as lomefloxacin, enrofloxacin, sarafloxacin and flumequine, presented the homology features originating from the emission of medical treatment and aquaculture. There was no potential risk of QNs to human beings but a potential risk to aquatic organisms (algae > plant > invertebrate). Totally, the management and protection of Yancheng coastal wetland should be of concern with aquaculture as the important industry. [ABSTRACT FROM AUTHOR]

Foundation species support highly productive and valuable ecosystems, but anthropogenic disturbances and environmental changes are increasingly causing foundation species shifts, where one foundation species replaces another. The consequences of foundation shifts are not well understood, as there is limited research on the equivalency of different foundation species and the functions they support. Here, we provide insight into community-level consequences of foundation shifts in the Gulf of Mexico, where the typical marsh foundation species (Spartina alterniflora) is being replaced with a mangrove foundation species (Avicennia germinans), forcing marsh fauna to rely on Avicennia for foundational support. We evaluated the interactions of two common and ecologically valuable basal consumers, fiddler crabs (Uca spp.) and marsh periwinkle snails (Littoraria irrorata), with both foundation species across sites with different levels of mangrove encroachment. By investigating both physical support, measured as habitat association and co-occurrence, and trophic support, as basal resource diet contributions, we found that Avicennia can physically replace Spartina for some consumers, but is not providing equivalent trophic support. Uca and Littoraria commonly occupy encroached sites and associate with mangroves but incorporate almost no mangrove plant matter into their diets. The ultimate consequences of a foundation shift in the case of mangrove encroachment may include shifting energy flows and resource use and decreased populations of basal consumers. Looking at interactions with foundation species from multiple perspectives is necessary to obtain a complete picture of the effects that foundational shifts are having, especially as such shifts are becoming increasingly common. [ABSTRACT FROM AUTHOR]

Coastal marsh ecosystems are changing and being lost at a rapid rate around the world. One of the fastest rates of land loss, specifically coastal marsh habitat, occurs in Louisiana on the Northern Gulf Coast of the USA. To address this issue, state and federal agencies have undertaken massive wetland restoration efforts to preserve and restore coastal marsh habitats in Louisiana. For these efforts to be successful in the long-term, it is critical to understand what methodologies and techniques result in resilient restoration projects. However, traditional methods to monitor restoration success rely on labor intensive field measurements that are often limited in scope, difficult to maintain, and underfunded. Recent technological developments with uncrewed aircraft systems (UASs) and image processing have substantially improved the ability of restoration practitioners to use off-the-shelf UASs and cameras to map projects. We present a streamlined method using a commercially available drone with a high-resolution red, green, blue (RGB) camera to assess the effects of wetland restoration and integrate more modern tools into evaluation approaches. We conducted drone flights at restored brackish marshes of various ages using a space for time substitution with the goal of understanding the long-term success of marsh restoration. We observed that created marshes had higher land to water ratios than natural marshes. This finding suggests that these restored areas were gaining and maintaining elevation after approximately 10 years. Our method shows that drone surveys offer low-cost, minimally invasive methods for evaluating restored wetlands and ultimately tell us more about ecosystem function through realistic site-level habitat configurations. [ABSTRACT FROM AUTHOR]

Coastal wetlands are important areas with valuable natural resources and diverse biodiversity. Due to the influence of both natural factors and human activities, the landscape of coastal wetlands undergoes significant changes. It is crucial to systematically monitor and analyze the dynamic changes in coastal wetland cover over a long-term time series. In this paper, a long-term time series coastal wetland remote sensing classification process was proposed, which integrated feature selection and sample migration. Utilizing Google Earth Engine (GEE) and Landsat TM/ETM/OLI remote sensing image data, the selected feature set is combined with the sample migration method to generate the training sample set for each target year. The Simple Non-Iterative Clustering-Random Forest (SNIC-RF) model was ultimately employed to accurately map wetland classes in the Liaohe Estuary from 1985 to 2023 and quantitatively evaluate the spatio-temporal pattern change characteristics of wetlands in the study area. The findings indicate that: (1) After feature selection, the accuracy of the model reached 0.88, and the separation of the selected feature set was good. (2) After sample migration, the overall accuracy of sample classification in the target year ranged from 87 to 94%, along with Kappa coefficients of 0.84 to 0.92, thereby ensuring the validity of classification sample migration. (3) SNIC-RF classification results showed better performance of wetland landscape. Compared with RF classification, the overall classification accuracy was increased by 0.69-5.82%, and the Kappa coefficient was increased by 0.0087-0.0751. (4) From 1985 to 2023, there has been a predominant trend of natural wetlands being converted into artificial wetlands. In recent years, this transition has occurred more gently. Finally, this study offers valuable insights into understanding changes and trends in the surface ecological environment of the Liaohe Estuary. The research method can be extended to other types of wetland classification and the comprehensive application of coastal wetland in hydrology, ecology, meteorology, soil, and environment can be further explored on the basis of this research, laying strong groundwork for shaping policies on ecological protection and restoration. [ABSTRACT FROM AUTHOR]

Over-summering of shorebirds refers to the phenomenon where certain species of shorebirds, primarily migratory, remain on their non-breeding grounds during the summer months for one or more years instead of migrating to their breeding grounds. The present study investigates the presence and abundance of over-summering shorebird species at four distinct sites covering 24 scanning points along the southeastern coasts of Tamil Nadu for 2017-2023. A total of 13 species were observed over-summering, with Lesser Sand Plover being the most dominant species, followed by Greater Sand Plover. Notably, 10 species were found across all four sites, while three species--Black-tailed Godwit, Bar-tailed Godwit, and Common Sandpiper--were exclusive to Dhanushkodi Lagoon, observed only during 2023. The study examined the year-wise abundance of these species, revealing a decline in over-summering shorebirds across all study sites. The Eurasian Curlew, Curlew Sandpiper, Bar-tailed & Black-tailed Godwits are the 'Near Threatened' species observed during the study. Furthermore, the research highlighted variations in Shannon species diversity index (H) location-wise and year-wise - Manoli Island (H = 2.25) in 2023; Dhanushkodi Lagoon (H = 1.8) in 2023; Valinokkam Lagoon (H = 1.63), and Pillaimadam Lagoon (H = 2.08) in 2017. Key findings are that among the study sites, in Pillaimadam Lagoon all 10 species' abundance declined; in Valinokkam Lagoon, Greater Sand Plover and Little Stint marginally increased, and eight species declined; Common Redshank and Ruddy Turnstone marginally increased in Manoli Island, while other eight species declined; Grey Plover population increased in Dhanushkodi Lagoon along with a marginal decrease in Common Redshank and Ruddy Turnstone as other species declined, over the years of study. [ABSTRACT FROM AUTHOR]

Peaty sediments in coastal wetlands play an important role in the sequestration of atmospheric carbon dioxide and its belowground storage. Sediment cores are used to quantify organic matter (OM) density, estimated by multiplying the bulk density of a core segment by its OM fraction. This method can be imprecise, as repeated samples often differ widely. Recent studies have shown that sediment bulk density and OM fraction are not independent but tightly related by a function called the ideal-mixing model. Thus, the bulk density of the sediment can be directly estimated from its OM fraction. Statistical theory and simulations demonstrate that the high variance in the product estimation of OM density is the result of error propagation in the product of two functionally related variables with independent errors. Estimating OM density in wetland sediments using the ideal-mixing model is more precise than the traditionally used product estimate, especially in highly organic sediments. [ABSTRACT FROM AUTHOR]

Suspended particulate matter (SPM) concentrations and associated estuarine high turbidity zones (HTZ) play crucial role in maintaining delta land building, coastal wetlands and marine ecosystems. In the background of new watersediment delivery regime and major geomorphological transition in delta, the long-term change characteristics and driving mechanisms of SPM and HTZ in the Yellow River Estuary (YRE) are not clarified. In this study, it was found that the existing SPM models could not be adapted to the extremely turbid YRE, for which a novel SPM retrieval algorithm and HTZ extraction method were developed. Spatiotemporal dynamics of SPM and HTZ in YRE from 1984 to 2023 were investigated using 798 Landsat TM/ETM+/OLI imageries. Results indicated that our proposed SPM algorithm outperformed all the previous models of YRE (R2 > 0.95, relative percentage difference (RPD)< 22%), and high accuracies were achieved for both satellite-derived SPM (RPD = 33.01%) and HTZ (overall accuracy = 94%). Over the last four decades, both SPM concentration and HTZ distribution area in YRE had demonstrated an increasing and then decreasing trend, reaching a peak around 1996. HTZ experienced four morphological transformations involving the circular shape surrounding coast (1984-1993), the enlarged southeasterly ovoid shape (1994-2007), the circle-like shape (2007-2017) and the thin northeasterly ovoid shape (2018-2023). Riverine sediment load and strong-wind frequency controlled 67% of interannual SPM variability in the study area, and the former contributed more. Moreover, combination of weakening ocean dynamics and coastal erosion, coarsening of sediments, and coastal defense structures led to an exponential decline of SPM concentrations in northern subregion. High sediment discharge and rapid accretion of estuarine spit in 1984-1996 resulted in increased SPM concentrations in southern subregion and a quick expansion of HTZ into Laizhou Bay. With the geomorphological evolution of new and old estuaries, the high velocity zone and strong bottom shear stress zone were consequently adjusted, which explained the interannual variability of SPM and HTZ in the region. This study will contribute to understanding of the long-term evolutionary patterns of the coupled system consisting of runoff-tidal dynamics, sediment transport and geomorphological development in the estuary. [ABSTRACT FROM AUTHOR]

Birds are sensitive to environmental changes and can drive range shifts rapidly due to their high mobility. Though previous studies have examined the associations between species traits and range shifts, whether species traits could still explain heterogeneity in shift directions remains poorly explored. Here, we compiled new bird records of China from 2000 to 2019 and analyzed species traits associated with apparent shift directions. We collected 350 provincial-level new records of birds belonging to 67 families of 22 orders. Of these, 32 are threatened, with 3 critically endangered, 11 endangered, and 18 vulnerable. Provinces in western China (i.e., Yunnan and Xizang) had relatively higher species richness of new recorded birds; this pattern was also reflected in the phylogenetic diversity we observed. In addition, provinces in northern China (i.e., Tianjin, Shandong, and Beijing) had relatively higher richness-controlled phylogenetic diversity. Phylogenetic overdispersion of new recorded bird communities was observed in 61.29% of provinces (19 of 31). The main shift directions indicated by new bird records were northward (with nearly 50% of birds moving NW, N and NE). Migration, hand-wing index (HWI), body mass, and range size are the four key factors that most significantly influence the shift directions in bird species, suggesting that bird movement toward newly suitable areas varies with species-specific traits. Together, these results demonstrate the importance of considering species ecological traits when predicting shift directions of birds. [ABSTRACT FROM AUTHOR]

Aim Location Time Period Major Taxa Studied Methods Results Main Conclusions The climate change‐induced transition from grass‐dominated marshes to woody‐plant‐dominated mangrove forests has the potential to impact the ecosystem goods and services provided by coastal wetlands. To better anticipate and prepare for these impacts, there is a need to advance understanding of future changes in mangrove distribution and coastal wetland vegetation structural properties due to warming winters.Southeastern United States.Recent (1981–2010) and future (2071–2100).Coastal wetland vegetation.We estimated changes in mangrove distribution and coastal wetland vegetation structure using known climate‐ecological relationships, recent climate data for the period 1981–2010, and future projected climate data for the period 2071–2100. We quantified potential changes in mangrove presence, mangrove relative abundance, coastal wetland vegetation height, and coastal wetland vegetation aboveground biomass under two Shared Socio‐Economic Pathway scenarios (SSPs; SSP2‐4.5 and SSP5‐8.5), which correspond to intermediate and high greenhouse gas emissions scenarios, respectively.Our analyses indicate that mangrove presence and relative abundance will dramatically increase in the northern Gulf of Mexico and the southeast Atlantic coast of the United States, particularly under the high emissions scenario. Because of the higher stature of mangroves relative to salt marsh vegetation, this expansion will cause a transformative change in coastal wetland vegetation height and aboveground biomass in many areas. However, along the arid southern Texas coast, low precipitation and high salinities are expected to constrain mangrove expansion and growth.Our results show where and to what extent climate change, in the form of winter temperature warming, is projected to enable the transition from shorter, grass‐dominated salt marshes to taller, woody plant‐dominated mangrove forests in the southeastern United States, with consequent impacts on ecosystem goods and services. [ABSTRACT FROM AUTHOR]

Quantifying the vegetation aboveground biomass (AGB) is crucial for evaluating environment quality and estimating blue carbon in coastal wetlands. In this study, a UAV-LiDAR was first employed to quantify the canopy height model (CHM) of coastal Phragmites australis (common reed). Statistical correlations were explored between two multispectral remote sensing data (Sentinel-2 and JL-1) and reed biophysical parameters (CHM, density, and AGB) estimated from UAV-LiDAR data. Consequently, the reed AGB was separately estimated and mapped with UAV-LiDAR, Sentinel-2, and JL-1 data through the allometric equations (AEs). Results show that UAV-LiDAR-derived CHM at pixel size of 4 m agrees well with the observed stem height (R2 = 0.69). Reed height positively correlates with the basal diameter and negatively correlates with plant density. The optimal AGB inversion model was derived from Sentinel-2 data and JL-1 data with R2 = 0.58, RMSE = 216.86 g/m2 and R2 = 0.50, RMSE = 244.96 g/m2, respectively. This study illustrated that the synergy of UAV-LiDAR data and multispectral remote sensing images has great potential in coastal reed monitoring. [ABSTRACT FROM AUTHOR]

Soil microorganisms play a crucial role in the plant invasion process, acting as both drivers of and responders to plant invasion. However, the effects of plant invasion on the complexity and stability of co-occurrence networks of soil microbial communities remain unclear. Here, we investigated how the invasion of Spartina alterniflora affected the diversity, composition, and co-occurrence networks of soil bacterial and fungal communities in the Yellow River Delta, China. Compared to the native plant (Suaeda salsa), S. alterniflora invasion decreased the α-diversity of soil bacterial communities but did not affect that of fungal communities. The β-diversity of soil bacterial and fungal communities under S. salsa and S. alterniflora habitats also differed dramatically. S. alterniflora invasion increased the relative abundance of the copiotrophic phylum Bacteroidota, whereas decreased the relative abundances of the oligotrophic phyla Acidobacteriota and Gemmatimonadota. Additionally, the relative abundance of Chytridiomycota, known for its role in degrading recalcitrant organic matter, increased substantially within the soil fungal community. Functional predictions revealed that S. alterniflora invasion increased the relative abundance of certain soil bacteria involved in carbon and nitrogen cycling, including aerobic chemoheterotrophy, nitrate reduction, and nitrate respiration. More importantly, S. alterniflora invasion reduced the complexity and stability of both soil bacterial and fungal community networks. The shifts in soil microbial community structure and diversity were mainly induced by soil available nutrients and soil salinity. Overall, our study highlights the profound impacts of S. alterniflora invasion on soil microbial communities, which could further indicate the modification of ecosystem functioning by invasive species. [ABSTRACT FROM AUTHOR]

The carbon sink of cultivation shellfish in coastal wetlands is characterized as both highly ecological and economic value, thus making great contributions to achieving carbon neutrality. In this study, the main species of cultured shellfish (Ruditapes philippinarum, Meretrix meretrix, Sinonovacula constricta, Scapharca suberenata, and Grassostrea gigas) were selected as the research objects in the coastal wetland of the Yalu River Estuary to measure shellfish yields and carbon contents. Combined with the data from the cultured shellfish of fishery statistics of Donggang city, Dandong, Liaoning Province, China, the carbon sequestration capacity was calculated, and the carbon sink values of cultured shellfish also evaluated on the base of the diverse shellfish carbon sequestration ratios. The carbon sink conversion ratio of cultivation shellfish decreased in the following order: S. suberenata, R. philippinarum, G. gigas, S. constricta, and M. meretrix. The total carbon sequestration of cultured shellfish in the Yalu River Estuary Coastal Wetland from 2015 to 2019 was approximately 110,500 tC. The yield and the carbon sequestration quantity of R. philippinarum accounted for 76.60~83.30% of the total yield and 79.07~85.41% of the total carbon sequestration quantity. The value of the carbon sink was approximately 63,710,600 yuan. Among the species of cultured shellfish, R. philippinarum was the largest contributor to the carbon sink value. Based on Tapio's decoupling model, R. philippinarum has the most ideal state of decoupling between carbon sink and economic growth of cultured shellfish, followed by M. meretrix and S. suberenata. Our results illustrate that the development of coastal wetland shellfish aquaculture has a positive contribution to reducing carbon emissions and increasing carbon sinks. [ABSTRACT FROM AUTHOR]

Coastal wetlands play an important role in the global water and biogeochemical cycles. Climate change makes it more difficult for these ecosystems to adapt to the fluctuation in sea levels and other environmental changes. Given the importance of eco-geomorphological processes for coastal wetland resilience, many eco-geomorphology models differing in complexity and numerical schemes have been developed in recent decades. However, their divergent estimates of the response of coastal wetlands to climate change indicate that substantial structural uncertainties exist in these models. To investigate the structural uncertainty of coastal wetland eco-geomorphology models, we developed a multi-algorithm model framework of eco-geomorphological processes, such as mineral accretion and organic matter accretion, within a single hydrodynamics model. The framework is designed to explore possible ways to represent coastal wetland eco-geomorphology in Earth system models and reduce the related uncertainties in global applications. We tested this model framework at three representative coastal wetland sites: two saltmarsh wetlands (Venice Lagoon and Plum Island Estuary) and a mangrove wetland (Hunter Estuary). Through the model-data comparison, we showed the importance of using a multi-algorithm ensemble approach for more robust predictions of the evolution of coastal wetlands. We also found that more observations of mineral and organic matter accretion at different elevations of coastal wetlands and evaluation of the coastal wetland models at different sites in diverse environments can help reduce the model uncertainty. [ABSTRACT FROM AUTHOR]

Coastal wetland ecosystems in the Gulf of Mexico provide a variety of services including high rates of carbon sequestration and storage, making their assessment and conservation essential. This study aimed to determine the spatial distribution of carbon stocks in protected and non-protected coastal wetland ecosystems along the Gulf of Mexico in Mexico. Aboveground carbon (AGC) and belowground carbon (BGC) stocks were quantified using predictive random forest models. The study analyzed carbon estimates in AGC and BGC across different coastal wetland ecosystems and assessed the carbon storage of protected areas (PAs) and non-protected areas (non-PAs) for carbon conservation. Field surveys provided biomass and soil carbon data for modeling training, incorporating environmental features such as canopy height, vegetation indices, and soil characteristics. The results reveal differences in carbon stocks quantities among various vegetation types, with mixed mangroves exhibiting the highest AGC stock (93.7 ± 8.4 Mg C ha−1) and herbaceous wetlands displaying the smallest range (3.9 ± 1.3 Mg C ha−1) across sites. Notably, cattail marshes showed the highest average BGC stocks (505.6 ± 86.8 Mg C ha−1), influenced by factors such as soil characteristics and land cover. Spatial distribution maps of AGC and BGC provided insights into areas of high and low carbon storage. Interestingly, non-PAs showed higher carbon stocks than certain PAs, emphasizing the importance of including both protected and non-protected areas in conservation efforts. These findings highlight the significance of carbon storage across coastal wetland ecosystems, and the need for comprehensive conservation strategies to preserve their valuable ecosystem services. [ABSTRACT FROM AUTHOR]

Simple Summary: Ecosystems store large amounts of carbon, contributing to the control of the gases that lead to climate change. At the same time, certain species provide beneficial materials for the production of fodder or organic fertilizers. This research measured the amount of carbon stored by, and the biomass provision potential of, a water lettuce (Pistia stratiotes) population in a disturbed and unprotected Peruvian coastal wetland ecosystem. The results indicated that this population stored 3942.57 tCO2 and that a potential 2132.41 tons of biomass could be obtained for fodder. This pioneering research in Peru measured these ecosystem services, demonstrating the potential of this population of floating aquatic plants to provide both services. One of the most fascinating wetlands on Peru's central coast is the Santa Rosa wetland (Chancay, Lima), an ecosystem threatened by anthropogenic activities. Some of these impacts have led to the uncontrolled growth of Pistia stratiotes, an invasive aquatic plant. This study sought to quantify the regulation and provisioning of ecosystem services provided by P. stratiotes using carbon storage and the provision of biomass as indicators. To this end, the biomasses of 50 plots measuring 0.0625 m2 were weighed and georeferenced and the percentages of dry biomass (%DB) and total organic carbon in the biomass (%C) were quantified. The biomass and its coordinates were entered into ArcGIS and a Kriging interpolation technique was applied to determine the total amount of biomass (B). It was found that P. stratiotes stored 3942.57 tCO2 and that 2132.41 tons of biomass could be obtained for fodder. The total carbon stored by this aquatic plant represented 28.46% of the total carbon sequestered in the wetland ecosystem by vascular plants, suggesting that its contribution to the carbon cycle is significant. This is the first study to estimate the biomass of a floating aquatic plant population in a coastal Peruvian wetland and is a pioneering study addressing the in situ carbon estimation of Peruvian floating aquatic plants. The results and methods proposed in this research will serve in the evaluation of the potential of ecosystem services among similar populations of floating aquatic species. In addition, the data presented can be used to establish plans for the management and use of this biomass in the production of soil fertilizers and cattle forage. [ABSTRACT FROM AUTHOR]

Mangrove ecosystems provide numerous ecological services and serve as vital habitats for a wide range of flora and fauna. Thus, accurate mapping and monitoring of relevant land covers in mangrove ecosystems are crucial for effective conservation and management efforts. In this study, we proposed a novel approach for mangrove ecosystem mapping using a Hybrid Selective Kernel-based Convolutional Neural Network (HSK-CNN) framework and multi-temporal Sentinel-2 imagery. A time series of the Normalized Difference Vegetation Index (NDVI) products derived from Sentinel-2 imagery was produced to capture the temporal behavior of land cover types in the dynamic ecosystem of the study area. The proposed algorithm integrated Selective Kernel-based feature extraction techniques to facilitate the effective learning and classification of multiple land cover types within the dynamic mangrove ecosystems. The model demonstrated a high Overall Accuracy (OA) of 94% in classifying eight land cover classes, including mangrove, tidal zone, water, mudflat, urban, and vegetation. The HSK-CNN demonstrated superior performance compared to other algorithms, including random forest (OA = 85%), XGBoost (OA = 87%), Three-Dimensional (3D)-DenseNet (OA = 90%), Two-Dimensional (2D)-CNN (OA = 91%), Multi-Layer Perceptron (MLP)-Mixer (OA = 92%), and Swin Transformer (OA = 93%). Additionally, it was observed that the structure of the network, such as the types of convolutional layers and patch sizes, affected the classification accuracy using the proposed model and, thus, the optimum scenarios and values of these parameters should be determined to obtain the highest possible classification accuracy. Overall, it was observed that the produced map could offer valuable insights into the distribution of different land cover types in the mangrove ecosystem, facilitating informed decision-making for conservation and sustainable management efforts. [ABSTRACT FROM AUTHOR]

Aboveground biomass (AGB) serves as a crucial indicator of the carbon sequestration capacity of coastal wetland ecosystems. Conducting extensive field surveys in coastal wetlands is both time-consuming and labor-intensive. Unmanned aerial vehicles (UAVs) and satellite remote sensing have been widely utilized to estimate regional AGB. However, the mixed pixel effects in satellite remote sensing hinder the precise estimation of AGB, while high-spatial resolution UAVs face challenges in estimating large-scale AGB. To fill this gap, this study proposed an integrated approach for estimating AGB using field sampling, a UAV, and Sentinel-2 satellite data. Firstly, based on multispectral data from the UAV, vegetation indices were computed and matched with field sampling data to develop the Field–UAV AGB estimation model, yielding AGB results at the UAV scale (1 m). Subsequently, these results were upscaled to the Sentinel-2 satellite scale (10 m). Vegetation indices from Sentinel-2 data were calculated and matched to establish the UAV–Satellite AGB model, enabling the estimation of AGB over large regional areas. Our findings revealed the AGB estimation model achieved an R2 value of 0.58 at the UAV scale and 0.74 at the satellite scale, significantly outperforming direct modeling from field data to satellite (R2 = −0.04). The AGB densities of the wetlands in Xieqian Bay, Meishan Bay, and Hangzhou Bay, Zhejiang Province, were 1440.27 g/m2, 1508.65 g/m2, and 1545.11 g/m2, respectively. The total AGB quantities were estimated to be 30,526.08 t, 34,219.97 t, and 296,382.91 t, respectively. This study underscores the potential of integrating UAV and satellite remote sensing for accurately assessing AGB in large coastal wetland regions, providing valuable support for the conservation and management of coastal wetland ecosystems. [ABSTRACT FROM AUTHOR]

Shrub encroachment in coastal wetlands leads to heterogeneous distribution of soil resources, which may affect soil particle size distribution (PSD). Fractal theory was widely used to quantify the characteristics of soil PSD. However, exploration on the spatial changes in PSD of deep soil layers due to shrub-encroached vegetation succession is limited. Multifractal theory and GIS spatial analysis tools were used to spatially quantify the changes in soil PSD at different soil layers (0–80 cm) in a coastal wetland landscape (100 × 120 m) encroached by a native shrub Tamarix chinensis in the Yellow River Delta (YRD), China. We also discussed the potential mechanisms of soil PSD changes contributed by shrub encroachment. The results showed that higher content of fine sand, medium sand and coarse sand, while lower content of silt and very fine sand in 0–10 cm were observed in T.chinensis patches than in single T. chinensis and bare land (p < 0.05). In 30–40 cm, however, T.chinensis patches have higher soil clay content (p < 0.05). The generalized dimensional spectrum and multifractal parameters indicated that soil PSD in shrub patch area exhibited greater width and higher heterogeneity. Multifractal method could explain the changes of soil PSD better than single fractal dimension (D), and the Capacity Dimension (D0) was the most effective one to quantify the soil PSD characteristics. The values of D0 showed a clear order of shrub patch > single shrub > bare land in each layer. In addition, the D0 suggested that influences of T.chinensis on soil PSD can remain 70 cm below the surface in our case. Considering the complex sedimentary process in the YRD, the processes of water and wind erosion mediated by shrub encroachment, the positive feedback based on plant preferences and the mixed effects of shrub and grass species might promote the redistribution of soil particle size. Encroachment in coastal wetland of the YRD caused changes in soil PSD, especially at the surface soil layer. Multifractal parameters could quantify subtle characteristics of soil PSD in shrub-encroached area. Our work indicates that shrub encroachment in coastal wetland plays a significant role in altering regional and even global soil environments.Highlights: The soil in Tamarix chinensis patches showed higher content of clay, fine sand, and medium sand than bare land as a result of shrub encroachment. Multifractal parameters, especially the capacity dimension (D0), were good indicators to reveal the characteristics of soil particle size distribution (PSD). The generalized dimensional spectrum indicated that soil PSD of T.chinensis patches have high heterogeneity. The impacts of shrub on soil PSD can extend up to 70 cm depth in this T.chinensis encroached area of the Yellow River Delta. [ABSTRACT FROM AUTHOR]

Wetland ecosystems have become one of the long-term solutions for mitigating global climate change due to their strong carbon sequestration potential. However, the key carbon cycle processes in wetland ecosystems still lack a systematic summary. In the context of wetland protection and restoration, there is still a lack of consensus on the technical pathways to realize carbon sink multiplication in wetland ecosystems. In this paper, the key processes of carbon cycle, such as photosynthetic carbon uptake, microbial carbon decomposition and carbon deposition and burial, are sorted out and summarized in four major wetland types, namely, swamp and peat wetlands, river and riparian wetlands, lake and lakeshore wetlands, and estuarine and coastal wetlands. Based on the key processes of carbon cycle, three technological pathways for carbon sink multiplication are proposed, including, vegetation carbon sequestration and sink enhancement technology, soil carbon emission reduction technology and carbon deposition and burial technology. The key technologies under each pathway are further refined. And the carbon sink effects of the carbon sink technologies in different wetland types are qualitatively described. Also, wetland protection and restoration methods in corresponding regions are given in the light of the regional characteristics of wetlands in China. This will provide a scientific basis for the strategy of doubling the carbon sinks of China's wetland ecosystems. [ABSTRACT FROM AUTHOR]

Background: Ecological restoration of coastal wetlands has become particularly urgent worldwide as wetland areas have declined dramatically over the past two decades. Aims: To understand the nitrogen allocation strategy of Scirpus mariqueter (S. mariqueter) and provide theory support for future wetland management and restoration. Methods: The study investigated the response mechanism of S. mariqueter to altitude spatial changes in Nanhui Dongtan from 2017 to 2019 using remote sensing imagery and field surveys. The ecological adaptability of S. mariqueter at different elevations (denoted as A, B, and C for elevations 2.40, 3.15, and 3.49 m, respectively) was analyzed through 15N stable isotope tracing technology. In July and September 2020, 15N‐enriched urea solution was uniformly sprayed onto the leaf surfaces of S. mariqueter at different sites. Plant samples were collected at the end of July and September, and the aboveground, belowground, seed, and rhizome biomass were measured, followed by 15N isotope tests. Results: (1) From 2017 to 2019, the biomass of S. mariqueter significantly increased in the elevation change of 0.44–0.48 m, with the maximum aboveground biomass increase of 488.70 g dm−2. The density also increased significantly in the elevation change of 0.13–0.43 m, peaking at 674.02 plants m−2; (2) during the growing period, the biomass of A, B, and C increased. The aboveground portion of the 15N allocation rate accounted for 74%–84%. The belowground portion of the 15N allocation rate positively correlated with elevation; (3) during the reproductive period, elevation positively correlated with the 15N distribution rate of seeds and corms, as well as the biomass allocation rate of seeds and aboveground portions. The 15N allocation rate of the corms was higher than that of seeds. Additionally, elevation exhibited a negative correlation with belowground biomass allocation rate. (4) Point A has the highest difference of above and belowground biomass proportion, and 15N isotope allocation. Area of point A is the critical area affecting vegetation expansion and should be paid more attention in the future work of coastal management and restoration. Conclusion: There is an adaption strategy of S. mariqueter that affects the plant‐soil interaction and the biogeomorphological development process along the elevation gradient. [ABSTRACT FROM AUTHOR]

Restorations of former cranberry farms ("bogs") aim to re-establish native wetland vegetation, promote cold water habitat, and attenuate nitrogen (N) delivery to coastal waters. It is unclear, though, how elements of restoration design such as microtopography, groundwater interception, and plant communities affect N removal via denitrification. In a recently restored riparian cranberry bog with created microtopography, we compared denitrification potential, nitrous oxide (N2O) yield of denitrification (ratio of N2O:N2O + N2 gases), in situ N2O fluxes, soil chemistry, and plant communities at the highest and lowest elevations within 20 plots and at four side-channel groundwater seeps. Denitrification potential was > 2 × greater at low elevations, which had plant communities distinct from high elevations, and was positively correlated with plant species richness (Spearman's rho = 0.43). Despite detecting high N2O yield (0.86 ± 0.16) from low elevation soils, we observed small N2O emissions in situ, suggesting minimal incomplete denitrification even in saturated depressions. Groundwater seeps had an order of magnitude higher denitrification potentials and 100–300 × greater soil NO3− concentrations than the typically saturated low elevation soils. Groundwater seeps also had high N2O yield (1.05 ± 0.15) and higher, but spatially variable, in situ N2O emissions. Our results indicate that N removal is concentrated where soils interact with NO3–rich groundwater, but other factors such as low soil carbon (C) also limit denitrification. Designing restoration features to increase groundwater residence time, particularly in low lying, species rich areas, may promote more N attenuation in restored cranberry bogs and other herbaceous riparian wetlands. [ABSTRACT FROM AUTHOR]

With the loss of substantial natural wetlands in coastal zones, artificial wetlands provide alternative habitats for many shorebirds. Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population. Satellite tracking technique can obtain high-precision location information of individuals day and night, providing a good technical support for the study of quantitative relationship between waterfowls and their habitats. In this study, satellite tracking method, Remote Sensing (RS) and Geographic Information System (GIS) technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta (YRD), China. The results showed that the breeding Pied Avocets had a small range of activity, with a total core and main home range of 33.10 km2 and 216.30 km2, respectively. This species tended to forage in the pond and salt pan during the day and night, respectively, with an unfixed staying time in the breeding ground. The distance between breeding ground and feeding ground was less than 6 km. It is emphasized that in addition to improving the conditions of the remaining natural habitats, effective managing artificial habitats is a priority for shorebird conservation. This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats, and alleviate human-bird conflicts and sustainable development of coastal zones. [ABSTRACT FROM AUTHOR]

The Sicilian wetlands (Italy) are seriously threatened by human activities and ongoing climate change. The loss of these wetlands as migratory stepping stones could severely hamper the migratory flow of many bird species along the central Mediterranean. Targeted actions for the conservation of the avifauna require thorough knowledge of the utilization that waterbirds make of these habitats. Aiming to inform planning for more satisfactory bird habitat management and bird diversity preservation along the Mediterranean migratory bird flyway, in this study, we inventoried the avian metacommunity of the coastal wetlands in Sicily during the most critical period of the year (July–September) and used a multilevel analytical framework to explore the spatiotemporal dynamics in bird species assemblages. We recorded 73 bird species, of which almost 90% were migratory and 30 belonged to Annex I of the Birds Directive. At the metacommunity level, we found that all the biodiversity metrics were low in July and approximately doubled in the successive sampling sessions (August–September), where they showed little if any change. At the community level, we detected two main clusters of wetlands with regard to species richness, of which one (wetlands Baronello, Gela, Gornalunga, and Roveto) was characterized by higher levels of species richness in nearly all the sampling dates. The pattern of species richness in the Sicilian wetlands was most similar between the first and second half of August, while July was very dissimilar from all the other sampling dates. At the guild level, we found a significant increase during July–September in the number of the species belonging to the "Mediterranean" migration guild and the "divers from the surface" and "surface feeders" foraging guilds. At the species level, we detected a significant temporal sequence of the occurrence of waterbird species: two species were only early dwellers in July, ten species were only late dwellers in September, and twenty-six species made use of the Sicilian wetlands all summer long. The spatial distribution of the waterbird species differed significantly between any pair of sampling dates. Overall, the Little Grebe, the Spotted Redshank, and the Little Tern were the bird species with the highest site infidelity; by contrast, the Black Stork, the Broad-billed Sandpiper, the European Golden Plover, the Common Shelduck, and the Black-necked Grebe changed their spatial distribution among wetlands the least during July–September. Our study allowed us to detect (1) the wetlands and (2) the waterbird species to which the priority for conservation should be assigned, as well as (3) the exact time span during July–September when conservation measures should be mandatory, and not only advisable. These results provide a broader insight of the space–time patterns in bird species assembly in the coastal wetlands of Sicily during the critical summer period. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAV) based methods for reconnaissance activities aim to update wetlands' health status and are safer and cost-effective considering that wetlands normally have saturated soils, dense vegetation and wildlife. Vegetation survey work in wetland areas needs many staff to ensure the safety of researchers and equipment. This paper describes the application of UAV technology to identify and demarcate vegetation communities in a dense BRIS (beach ridges interspersed with swales) coastal wetland. The methodology employed in this research has two steps. The first step involves the utilisation of UAV imagery and Geographic Information System (GIS) technology. The second step entails ground truthing, which involves validating tree species using 15 quadrants. The utilisation of UAVs in conjunction with ArcGIS 10.3 demonstrated that the unique characteristics of tree canopy morphology and tree heights could be assessed and analysed. The UAV-GIS results are compared to ground truthing results to validate tree communities' demarcation. The findings indicate that integrating two datasets, particularly tree canopy morphology and tree height, produced an acceptably accurate vegetation community demarcation. The tree canopy form of Hibiscus tiliaceus (Bebaru) was differentiated from the canopies of Acacia mangium and Nypa fruticans by analysing the image. The tree height analysis involved using ArcGIS 10.3 software to generate the digital surface model (DSM) and digital terrain model (DTM). Validation results indicate an 87% accuracy in the demarcation work. Hence, identification and demarcation of the vegetation communities could be achieved by utilising both tree canopy morphology and tree height data obtained from UAV. [ABSTRACT FROM AUTHOR]

Wetlands formed by natural sediment deposition account for a large proportion of new coastal lands, and these new wetlands usually have active ecosystems and obvious ecological effects. However, previous studies largely overlooked this sediment‐caused wetland expansion, and the spatiotemporal variation in these wetlands and future response to sea‐level rise (SLR) have not been determined. Here, we employed satellite observations to quantify the seaward expansion of coastal lands in China over the past two decades. A total land expansion of 6,651 km2 was found, and wetlands and artificial surfaces dominated, accounting for 32% and 25%, respectively. Subsequently, we utilized an integrated model to estimate the response of these new wetlands to SLR in the 21st century, that is, we estimated the wetland gain from sediment deposition and loss due to SLR. The results indicate that under the current condition of sediment availability, the area of China's new coastal wetlands is projected to increase by 200%–261% compared to that in 2020 based on four SLR scenarios, despite the unavoidable impact of SLR. These increases are accompanied by the continuous enhancement of carbon accumulation. Wetland changes are influenced by factors such as sediment deposition, SLR and storm surges, as well as the continued effect of local natural and anthropogenic factors. These results show the importance of understanding the ecological effects of new wetlands and constructing specific protection measures for sustainable development. Plain Language Summary: Compared to anthropogenic reclamation, sediment deposition represents an alternative mechanism for the formation of coastal lands. These newly formed lands possess highly dynamic ecosystems and offer additional land resources, making them immensely important for ecological environments and societal development. This study focused on the spatiotemporal changes in newly formed lands in China's coastal regions over the past two decades, and an examination of the land use status was conducted. The results show that wetlands constitute the predominant component of these new lands, rather than artificial surfaces. Using an integrated model, we estimated the future response of these new wetlands to sea‐level rise and the corresponding carbon accumulation trend. Additionally, the factors influencing the area of new wetlands was analyzed to provide valuable insights and recommendations for future wetland conservation policies. Key Points: A total of 6,651 km2 of newly formed coastal lands were found in China in the past 20 years, and wetlands were the predominant componentCarbon accumulation in China's new coastal wetlands is projected to increase by 200%–261% by 2100 under various sea‐level scenariosOur results show that wetland change is primarily driven by sediment availability and that wetland loss is maintained with sea‐level rise [ABSTRACT FROM AUTHOR]

Nitrate (NO3-) reduction is a key process governing the nitrogen (N) dynamics of coastal wetland sediments. Although the effects of environmental factors on the (NO3-) reduction mechanism in coastal wetland sediments have been examined in various studies, the effects of spatial variation in potential (NO3-) reduction processes in coastal wetland sediments and the factors driving geographical variation in these processes have not been widely examined. Here, we conducted research on surface sediment samples from four different vegetation types at six coastal wetland sites across two regions. We characterized potential rates of (NO3-) reduction processes (including denitrification (DF), anammox (ANA), and dissimilatory nitrate reduction to ammonium (DNRA)) using a15N tracer method. Additionally, we assessed the abundances of functional genes, and microbial community structure using high-throughput sequencing, and metagenomic sequencing. In six wetland sites, the contribution ranges of DF, ANA, and DNRA to (NO3-) reduction were 38.43%-55.69%, 31.33%-45.65%, and 5.26%-17.11%, respectively, and potential (NO3-) reduction was mainly driven by N removal via gaseous N (DF+ANA). Significant spatial differences were observed in the structure of bacterial and fungal microbial communities, suggesting that geographical distance has a major effect on microbial community structure. Environmental factors and Functional gene abundances were significantly related to potential (NO3-) reduction processes, and physicochemical properties had a stronger effect on potential (NO3-) reduction processes than gene abundances. Factors showing significant differences across regions were the main drivers of variation in potential (NO3-) reduction processes. Overall, our study showed that sediment substrates and geographical environmental factors rather than the abundance of functional genes and vegetation types were the main indicators of potential (NO3-) reduction activities in coastal wetlands. [ABSTRACT FROM AUTHOR]

Invasive Spartina alterniflora (S. alterniflora) has significant impacts on sediment biogeochemical cycling in the tidal wetlands of estuaries and coasts. However, the impact of exotic Spartina alterniflora invasion on greenhouse gases (GHGs) production dynamics in sediments remain limited. Here, we investigated the dynamics of sediment physicochemical properties, GHGs production rates, and microbial gene abundances in a native Cyperus malacensis habitat and three invasive S. alterniflora habitats (6-, 10-, and 14-year) in the Minjiang River Estuary, China. The methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) production rates varied both spatially and seasonally, while microbial gene abundances (bacterial and fungal gene abundances) and organic matter (TOC and TN) only varied spatially. GHGs production rates were also characterized by higher values in surface sediment (0-10 cm) compared to subsurface sediment (10-20 cm) and by seasonal variations with higher values in summer than in winter. S. alterniflora invasion can significantly increase CH4 and CO2 production rates, organic matter, and microbial gene abundances (p < 0.05). Temperature, organic matter and microbial gene abundances were the most dominating factor controlling the spatio-temporal variations of CH4 and CO2 production rates. Overall, our findings highlighted the significant role of S. alterniflora invasion in regulating GHGs production rates in coastal wetland sediments and provided fundamental data for estimating GHGs emissions and carbon sequestration in the complex tidal wetlands. [ABSTRACT FROM AUTHOR]

Mangrove wetland restoration projects have been conducted for many years and it is important to evaluate their success. In this study, we explored the role of monitoring macrobenthos in assessing the success of mangrove restoration. In particular, we sampled soil and macrobenthos from a mangrove wetland area after restoration for one, three, and five years in the Pearl River Estuary Delta in China to explore the effects of different restoration periods on the macrobenthos community structure. The results showed that the macrobenthos collected in the study area mainly comprised Polychaete annelids and Bivalvia mollusks, and there were no significant differences in the species, biomass, richness index, diversity index, and evenness index among different mangrove wetland restoration stages. The macrobenthos biomass, species richness, diversity index, and evenness index were mainly correlated with the soil electrical conductivity, pH, total phosphorus, and soil organic carbon. Compared with mangrove restoration for one year, the average species richness, Margalef richness index, Shannon diversity index, and Pielou evenness index for macrobenthos were significantly higher after three years, thereby indicating that the macrobenthos species diversity increased significantly after mangrove wetland restoration for three years. However, the macrobenthos diversity was lower after mangrove wetland restoration for five years, which may have been due to human activities and soil pollution. The findings obtained in this study provide basic information to facilitate mangrove wetland restoration and conservation. [ABSTRACT FROM AUTHOR]

The spatial pattern of leaf stoichiometry is critical in predicting plant palatability and ecosystem productivity and nutrient cycling rates and thus is a major focus of community ecological research. Coastal wetlands as vital blue carbon ecosystems, with high possibility to be vulnerable to plant invasion, studies focused on stoichiometry and its pattern are important to unveil the elements cycling process. However, previous studies have mainly focused on stoichiometry in terrestrial ecosystems, there are few studies conducted on coastal wetland ecosystems, especially the studies that compare leaf stoichiometry between native and non-native plants in coastal wetlands. In this study, we compared the latitudinal patterns of leaf nutrient contents and their stoichiometric ratios between native and non-native plant species across coastal wetland ecosystems and investigated whether leaf stoichiometric patterns were driven by climatic factors. We used a compiled global data set of 954 records to conduct a systematic meta-analysis. The results showed that there were significant differences in latitudinal patterns of leaf carbon (C) and nitrogen (N) contents and C:N ratio between native and non-native species, as well as significant differences in leaf C, N, and phosphorus (P) contents. For native species, we found significant latitudinal patterns in leaf C, N, and P contents and C:N and C:P ratios, whereas for non-native species, we found significant latitudinal patterns in leaf N content and C:P and N:P ratios. Mean annual temperature of the data collection site was a significant predictor of leaf stoichiometry of native plants but only of leaf N content and C:P ratio of nonnative plants. Thus, we demonstrated spatial heterogeneity in leaf stoichiometries between native and non-native plants in coastal wetlands, indicating that such differences should be emphasized in future biogeochemical models and plant-herbivore interaction studies owing to the important role of wetland plants in global C, N, and P cycles. Our findings increase understanding of plant-related nutrient and elements cycling in coastal wetlands, as well as improve predictions of plant growth rates and vegetation productivity across large scales under plant invasion scenarios. [ABSTRACT FROM AUTHOR]

Tidal creeks play a vital role in influencing geospatial evolution and marsh ecological communities in coastal landscapes. However, evaluating the geospatial characteristics of numerous creeks across a site and understanding their ecological relationships pose significant challenges due to the labor-intensive nature of manual delineation from imagery. Traditional methods rely on manual annotation in GIS interfaces, which is slow and tedious. This study explores the application of Attention-based Dense U-Net (ADU-Net), a deep learning image segmentation model, for automatically classifying creek pixels in high-resolution (0.5 m) orthorectified aerial imagery in coastal Georgia, USA. We observed that ADU-Net achieved an outstanding F1 score of 0.98 in identifying creek pixels, demonstrating its ability in tidal creek mapping. The study highlights the potential of deep learning models for automated tidal creek mapping, opening avenues for future investigations into the role of creeks in marshes' response to environmental changes. [ABSTRACT FROM AUTHOR]

The impacts of climate change are reaching unprecedented levels, heightening the risk of species loss and ecosystem service degradation. Wetlands, highly threatened ecosystems, serve vital ecological functions by capturing carbon, filtering water, and harbouring diverse wildlife. Coastal wetlands encounter many challenges, such as increased drought periods and escalating salinity levels, severely impacting plant biodiversity. Assessing how plants respond to various environmental stress factors is imperative for devising successful conservation strategies. In the present study, we examined three representative grass species found in various habitats within the Albufera Natural Park, close to the city of Valencia on the Spanish Mediterranean coast: Imperata cylindrica, Phragmites australis, and Saccharum ravennae. High salinity and water stress conditions were induced by subjecting the plants to irrigation with solutions containing 200, 400, 600, and 800 mM NaCl or withholding irrigation altogether to mimic coastal flooding and drought scenarios. The treatments were maintained until noticeable wilting of the plants occurred, at which point a range of stress biomarkers were determined, including photosynthetic pigments, ions, osmolytes, oxidative stress markers, and antioxidant metabolites, as well as antioxidant enzyme activities. Saccharum ravennae displayed the highest sensitivity to salt stress, whereas I. cylindrica appeared to be the most tolerant. The primary salinity tolerance mechanism observed in I. cylindrica and P. australis was a blockage of ion transport from the root zone to the aerial part, together with the salt-induced accumulation of proline and soluble sugars to high concentrations in the former. No significant effects of the water deficit treatment on the growth or biochemical parameters were observed for any of the analysed species. These findings offer valuable information for the effective management and conservation of coastal wetlands facing the challenges posed by climate change. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to investigate the impact of human activities on the evolution of coastal wetlands in the Liaohe River Delta. Understanding these impacts is crucial for the management, protection, and sustainable development of the ecological environment in the region. Methods: Quantitative analysis of the evolution of coastal wetlands along the Liaohe River from 1995 to 2020 using Landsat series remote sensing images. This study examines the changes in different landscapes and explores the impact of human activities on wetlands through methods such as land transfer matrix, landscape pattern index, and human activity hotspots. Results: The results show that the area of coastal wetlands in the Liaohe River Delta exhibited a fluctuating downward trend from 1995 to 2020. The eastern and western parts of the delta experienced greater disturbance to wetland landscapes due to human activities, while the northern and southern parts were mostly waters and reed lands with a smaller degree of human disturbance. Human activities have led to significant changes in farmland, ponds, rice paddies, construction land, and reed fields, thereby promoting the evolution of coastal wetlands. Discussion: This article discusses the characteristics of landscape pattern evolution in the study area, as well as the impact of human interference, economy, policies, and other factors on it, and compares it with the evolution patterns of other coastal wetlands in China. The changes in the landscape pattern of the study area are mainly reflected in the reduction and fragmentation of natural wetland areas, which are closely related to human activities, especially the development of construction and agriculture. The main economic manifestation is that the increase in land demand due to economic and urban development has led to the transformation of natural wetlands into construction land and other artificial landscapes. The implementation of regulations such as the Wetland Protection Law has contributed to the rational use and ecological restoration of wetlands, and also reflects the influence of policy factors. Compared with other studies, coastal wetlands in China generally face issues of degradation and loss, mainly caused by human activities, but also affected by natural factors such as rising sea levels, changes in coastlines, and climate change. [ABSTRACT FROM AUTHOR]

Assessing the hazard of inundation due to extreme storm surges in low-lying coastal areas and fragile ecosystems has become necessary and important. In this study, Xincun Lagoon and Li'an Lagoon in the Lingshui area of Hainan, China, were selected as the study areas, a high-resolution storm surge inundation numerical model was established, and the model reliability was tested. Based on data on typhoons affecting the study area from 1949 to 2022, the typhoon parameters for the extreme storm surge scenario were set and used for model numerical simulation and hazard assessment. The results revealed that in the extreme storm surge scenario, the average maximum tidal level, average maximum flow velocity, maximum inundation area, and average maximum inundation depth in the lagoon area were 2.29 m, 1.03 m/s, 14.8124 km2, and 1.20 m, respectively. Under the extreme storm surge scenario, a flow velocity of 2.0 m/s off the coasts of the lagoons could damage coastal aquaculture facilities, harbors, and ecosystems, while an inundation depth exceeding 1 m along the coasts of the lagoons could lead to the salinization of inundated land and severely affect the safety of residents. The hazard analysis of storm surge inundation in the land area of the lagoons revealed that hydrographic nets and coastal wetlands are the major land types inundated by storm surges, with the two accounting for approximately 70% of the total inundation area. According to China's technical guidelines, the hazard levels of the inundated land area of the lagoons are mostly level 3 (moderate hazard) and level 2 (high hazard), together accounting for approximately 90% of the total inundation area. If the government deems the measures feasible based on strict estimation and scientific evaluation of economic benefits and disaster prevention, planting mangroves in coastal wetlands and/or establishing adjustable tidal barriers at narrow entrances to lagoons could minimize disaster losses. [ABSTRACT FROM AUTHOR]

Coastal wetlands, often referred to as the 'kidneys of the Earth', have gained significant attention. However, they are increasingly affected by severe pollution and invasive species. Thus, ensuring green and sustainable methods for pollutant removal is of utmost importance. Biochar has demonstrated its unique advantages and benefits in coastal wetland remediation and management. In addition, the application of artificial intelligence (AI) in environmental fields has become increasingly prevalent, with the aim of improving the efficiency and effectiveness of environmental protection and resource management. However, the in situ remediation with AI-assisted biochar is still not well understood. This review adopts a problem-focused approach, analyzing and resolving problems to comprehensively review state-of-the-art biochar production, modification, and applications. This study aims to improve the remediation efficiency of sediment with combined pollution through the integration of AI systems. Moreover, the study highlights the positive effects of biochar on plant growth, microbial activity, and soil/sediment health, as well as its suitability for coastal wetland management, indicating that biochar holds great promise as an effective method for coastal wetland remediation and management. [ABSTRACT FROM AUTHOR]

This editorial provides an overview of the challenges faced by estuarine wetlands due to human activities and global climate change. It emphasizes the need for ecological restoration and adaptive management to protect the biodiversity and ecosystem services provided by these wetlands. The article discusses advancements in underground ecological observation technologies and their impact on estuarine wetlands, including plant root growth and their ability to absorb water and ions. It also explores the effects of plant root allelopathy, soil physicochemical properties, and bioturbation by burrowing organisms on plant-soil interactions and nutrient migration. The article highlights the importance of ecological restoration projects in mitigating degradation and improving the resilience of estuarine ecosystems, while acknowledging the challenges and the need for innovative approaches. It concludes by emphasizing the importance of monitoring restoration efforts and understanding long-term adaptation in estuarine wetland habitats. [Extracted from the article]

The differences inmass loss of leaf litter are primarily thought to be driven by microbial activity, especially by fungi. However, the existence of such differences across large spatial scales has not been well explored in field studies and the underlying mechanisms of difference are still unclear, especially for the role of different fungal guilds in driving different mass losses. We conducted a 1-year decomposition study within each of four coastalwetlands inChina to test the difference inmass loss across a large spatial scale (ranging from 26° N to 41° N in latitude). In each wetland, six sites including three composed of P. australis and three composed of another dominant plant species typically in coastal ecosystems were selected. We used P. australis leaf litter as the standard decomposition material, placing it into litter bags with mesh sizes 1mm and 4 mm, respectively. Final litter mass loss was examined approximately after 3, 9 and 12months. The differentmass loss was quantified using additionalmass loss at P. australis sites compared to that at another species sites. We found that themass loss of leaf litter of P. australis showed a clear difference across multiple coastal wetlands only at later stages of decomposition, which was independent of mesofauna (mesh size) contribution to decomposition. Furthermore, the observed difference in mass loss was primarily attributed to the dissimilarities in initial soil fungal community, particularly the symbiotrophic fungi, rather than the soil bacterial community. Our results provide empirical evidence of a large-scale difference in mass loss in litter decomposition and have linked the observed difference to different soil fungal guilds. These results indicate that symbiotrophic fungi might play a direct or indirect role in driving difference inmass loss, which contributes to a better understanding and invites in-depth further investigation on the underlying microbe-driven mechanisms of the difference. [ABSTRACT FROM AUTHOR]

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures. [ABSTRACT FROM AUTHOR]

Coastal lagoons are valuable ecosystems, providing socioeconomic benefits and supporting human populations and biodiversity. However, these systems face several challenges, making them vulnerable to both natural and human factors. In this study, we apply the Driver-Pressure-State-Impact-Response (DPSIR) Approach to conduct a comprehensive socioeconomic and environmental assessment of the Khenifiss Lagoon to promote sustainable development and support decision-makers. Located on the southern Atlantic coast of Morocco, the lagoon was designated a natural reserve in 1962, a biological reserve in 1983, and a protected wetland under the Ramsar Convention since 1980. This study represents the initial endeavor to conduct a comprehensive global and multidisciplinary environmental assessment of the lagoon by using a wide range of data sources, including relevant publications and reports, satellite images and remote sensing data, field observations, and interviews, all analyzed under the DPSIR framework. Our findings show that both natural and human factors have an impact on the ecosystem. Natural Factors associated with the geomorphological features of the region likely contribute to the silting of the lagoon, possibly intensified by a large shipwreck stuck at its inlet. Meanwhile, human factors encompass population growth (at a rate of 2% per year), tourism, shellfish farming, fishing, shellfish harvesting, and salt extraction. Our results reveal significant changes in the lagoon's condition in recent years, including a reduction in water body extent, a probable decrease in depth, and an increase in the accumulation of solid waste, plastics, and wastewater in three sectors spanning a total surface area of 464 ha (equivalent to 7% of the lagoon), a substantial expansion of the salt mining area encompassing 368 ha, and a remarkable loss of biodiversity, manifested in declining fish stocks and seabird populations. This study showed that the lagoon is positioned as a potential site for economic growth and serves to alert stakeholders and the local population to the ecosystem's environmental issues. Based on the findings of this study, we highly recommend regulating human activities within the lagoon, the removal of the wreck at the entrance, proper waste management, community awareness programs, and strict monitoring and enforcement of regulations to protect the environment. [ABSTRACT FROM AUTHOR]

The International Union for Conservation of Nature (IUCN) Red List identifies threatened and endangered species and is a key instrument in global biodiversity conservation efforts. Our understanding of the structure and value of genetic biodiversity below the species level is rapidly increasing. Nonetheless, the IUCN assessment criteria overlook genetic variation within species. Here, we address this blind spot and discuss the principles of species conservation status classification relative to intraspecific biodiversity. We focus on coastal species, which thrive in heterogeneous environments known to drive genetic differentiation. The focal example species, Atlantic cod and sugar kelp, have contrasting life histories, are ecologically and economically important constituents of the coastal ecosystem, and are currently not classified as threatened in Norway and Canada. We expose important variation in population structure, the presence of ecotypes and genetic-environment covariation, as well as loss of ecotypes that threatens the conservation of these species. Because the genetic makeup of species directly influences their resilience, omitting this information from conservation status assessments can result in loss of adaptive capacity to future stressors, such as climate change. Consequently, recognizing and preserving intraspecific variation emerges as vital for species' abilities to adapt to and survive in future ocean conditions. [ABSTRACT FROM AUTHOR]

Understanding global sea level variations and exploring their causes hold significant importance for future climate change predictions and the sustainable development of mankind, with the steric sea level (SSL) variations being one of the primary contributors to these changes. Here, we utilize four types of temperature and salinity products (i.e., EN4, IAP, SODA, and GDCSM) to investigate the spatiotemporal characteristics of global SSL changes from 1980 to 2020. We also explore the relationship between SSL changes and the El Niño-Southern Oscillation (ENSO) phenomenon. The findings reveal a rising trend of 0.64–0.97 mm/a in global SSL over the past 40 years, and the annual amplitudes of SSL time series are within the range of 0–50 mm. The SSL trend at a depth of 0–100 m exerts the greatest influence on the overall trend. The ENSO phenomenon has an obvious influence on sea level changes both in the equatorial Pacific region and global scale. The changes in the global sea level (GSL) associated with ENSO are primarily caused by changes in SSL. This study benefits the understanding of SSL changes and their connection to climate change, serves as a reference for comprehensively assessing sea level change mechanisms using diverse datasets and remote sensing technology, and further provides a scientific basis for the sustainable development of mankind in coastal areas. [ABSTRACT FROM AUTHOR]

Saltmarshes are carbon-rich ecosystems that play a role in climate regulation by efficiently sequestrating atmospheric CO2. Climate change is a major threat to saltmarshes and will impact saltmarsh carbon sequestration. Notably, porewater-derived carbon outwelling emerges as a crucial pathway for carbon sequestration, but it has been largely overlooked in saltmarshes. Here, we assessed the drivers of dissolved carbon exports and greenhouse gas emissions in a saltmarsh and placed those observations into a global context. In our study site, porewater exchange (PEX) was the major process controlling dissolved carbon and greenhouse gas dynamics. Combining our results with 33 other studies in saltmarshes worldwide, porewater-derived carbon fluxes were equivalent to ∼48% of average global saltmarsh primary productivity and 2.2 times greater than global organic carbon burial. Hence, our local observations and global upscaling demonstrate the major role played by PEX in saltmarsh carbon budgets. While part of dissolved inorganic carbon returns to the atmosphere as CO2, the remaining bicarbonate fraction is stored in the ocean over long time scales. Our findings strengthen global blue carbon assessments and build arguments for the use of saltmarshes as nature-based solutions for global climate change. [ABSTRACT FROM AUTHOR]

Fish production integrates changes in biomass from growth, reproduction, and mortality, and is a useful indicator for fisheries management. However, calculation of fish production has been limited by the intensive requirements for data on abundance, biomass, age structure, and vital rates, and so it is uncommon to find estimates of fish production for wetlands. We developed an approach to directly estimate production that is suitable for data-limited systems: a continuous time model of production describing individual growth over short time intervals with continuous time models of abundance and biomass over longer timescales. We applied this model for 18 Great Lakes coastal wetlands (GLCWs) on Lake Ontario, including Big Island Wetland (BIW). In BIW, most species were dominated in abundance and biomass by younger cohorts and, as a result, these young, fast-growing individuals contributed disproportionately to fish production. In total, BIW produced 336.1 kg·ha·year of fish and the other 17 neighbouring ranged between 447.7 and 1119.9 kg·ha·year. These are some of the first estimates of fish production for GLCWs, highlighting their value for managing Great Lakes fisheries. [ABSTRACT FROM AUTHOR]

In recent years, synthetic aperture radar (SAR) interferometry (InSAR) has emerged as a valuable tool for measuring water level change (WLC) to study hydrodynamic processes in coastal wetlands. However, the highly dynamic wet atmosphere conditions common in these areas have a significant impact on InSAR observations, producing errors in the derived values. Standard methods for estimating atmospheric noise in InSAR time series lack the spatial or temporal resolution needed to adequately correct for wet tropospheric delays. In this study, we utilize the Independent Component Analysis (ICA) signal decomposition technique to identify the likely WLC signal and eliminate atmospheric noise in a time series derived from rapid repeat measurements made with the L‐band uninhabited aerial vehicle synthetic aperture radar airborne instrument. The method compares in‐situ water level measurements with the independent components (IC) to identify the ICA components corresponding to WLC. The signal‐to‐noise ratio between the WLC after the ICA‐based filtering and in situ water level gauges used for validation reaches 16 dB compared to an average of 2.6 dB before filtering. The excluded IC are used to generate maps showing a time series of likely atmospheric features. The identified features in the maps generally correspond to atmospheric features identifiable in Next Generation Weather Radar (NEXRAD) S‐band ground weather radar reflectivity maps collected during the SAR acquisitions. The method is sufficiently general to be applied to any InSAR‐derived surface displacement time series. Key Points: Independent Component Analysis (ICA) is used to remove the wet troposphere noise in an InSAR‐derived time series of water level change in wetlandsIn‐situ data are used to identify components showing water level change and the other components used to generate tropospheric delay mapsThe filtered water level change values have improved accuracy based on measurements from water gauges located throughout the wetlands [ABSTRACT FROM AUTHOR]

Methane (CH4) emissions from wetland ecosystems are controlled by redox conditions in the soil, which are currently underrepresented in Earth system models. Plant-mediated radial oxygen loss (ROL) can increase soil O2 availability, affect local redox conditions, and cause heterogeneous distribution of redox-sensitive chemical species at the root scale, which would affect CH4 emissions integrated over larger scales. In this study, we used a subsurface geochemical simulator (PFLOTRAN) to quantify the effects of incorporating either spatially homogeneous ROL or more complex heterogeneous ROL on model predictions of porewater solute concentration depth profiles (dissolved organic carbon, methane, sulfate, sulfide) and column integrated CH4 fluxes for a tidal coastal wetland. From the heterogeneous ROL simulation, we obtained 18% higher column averaged CH4 concentration at the rooting zone but 5% lower total CH4 flux compared to simulations of the homogeneous ROL or without ROL. This difference is because lower CH4 concentrations occurred in the same rhizosphere volume that was directly connected with plant-mediated transport of CH4 from the rooting zone to the atmosphere. Sensitivity analysis indicated that the impacts of heterogeneous ROL on model predictions of porewater oxygen and sulfide concentrations will be more important under conditions of higher ROL fluxes or more heterogeneous root distribution (lower root densities). Despite the small impact on predicted CH4 emissions, the simulated ROL drastically reduced porewater concentrations of sulfide, an effective phytotoxin, indicating that incorporating ROL combined with sulfur cycling into ecosystem models could potentially improve predictions of plant productivity in coastal wetland ecosystems. [ABSTRACT FROM AUTHOR]

Coastal ecosystems are rapidly shifting due to changes in hydrologic presses (e.g., sea‐level rise) and pulses (e.g., seasonal hydrology, disturbances, and restoration of degraded wetlands). Changing water levels and sources are master variables in coastal wetlands that can alter carbon concentrations, sources, processing, and export. Yet, how long‐term increases in water levels from marine and freshwater sources influence dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) composition is uncertain. We quantified how long‐term changes in water levels are affecting DOC concentration (2001–2021) and DOM composition (2011–2021) differently across the Florida Everglades. DOC concentrations decreased with high water depths in peat marshes and increased with high water levels in marl marshes and across mangroves, and these relationships were reproduced in freshwater peat marshes and shrub mangroves. In the highly productive riverine mangroves, cross‐wavelet analysis highlighted variable relationships between DOC and water level were largely modulated by hurricane disturbances. By comparing relationships between water level and DOC concentrations with carbon sources from DOM fluorescence indices, we found that changing water sources between the dry and wet season shift DOM from algal to detrital sources in freshwater marshes, from detrital marsh to detrital mangrove sources in the brackish water ecotone, and from detrital mangrove to algal marine sources in downstream mangroves. As climate change and anthropogenic drivers continue to alter water levels in coastal wetlands, integrating spatial and temporal measurements of DOC concentrations and DOM compositions is essential to better constrain the transformation and export of carbon across these coastal ecosystems. Plain Language Summary: Water inputs to coastal ecosystems are changing in response to both sea‐level rise and water management. Changes in the amount and source of water can have different effects on organic carbon cycling across coastal ecosystems. We analyzed 20 years of data from the Florida Everglades to understand how changing water levels control carbon cycling. Our results show that higher water levels dilute carbon concentrations, and slow the release of carbon from peat soils, while also contributing to the transport of organic carbon downstream. We additionally found evidence of seasonal shifts in the composition of organic carbon, with higher algal contributions in the dry season for freshwater sites and higher marine contributions during the dry season for sites with marine influence. Our findings highlight that inputs, of both fresh and marine water, are transporting carbon within and between coastal wetlands, but only freshwater inputs prevent the release of carbon from peat stores. This research provides valuable insights into how inputs of water from different sources control the production, release, and movement of carbon throughout coastal wetland ecosystems. These insights are needed to preserve the value of organic carbon stored in coastal ecosystems, as the water within them changes. Key Points: Dissolved organic carbon concentrations decrease with water level in peat marshes but increase with level in mangroves and marl marshesDetrital carbon is mobilized by both fresh and marine hydrologic pulses, but only stored during freshwater hydrologic pulsesFreshwater restoration is increasing humic, colored dissolved organic matter entering the Everglades [ABSTRACT FROM AUTHOR]