Marsh Research Articles

Reconstructing the rapid transitions of ecosystems during the mid-late Holocene: A pollen record from Haixing wetland in Bohai Bay, North China

Vegetation in coastal regions is sensitive to climate and sea-level changes. However, currently there is still a lack of understanding about the stability of the Holocene coastal ecosystem and the rapid conversion processes of different coastal wetland ecosystems. In this study, the high-resolution vegetation succession history of the southwest coast of Bohai Bay during the mid-late Holocene was revealed, based on pollen analysis and REVEALS model, and the rate of vegetation change was estimated. Furthermore, the characteristics and mechanisms of different ecosystem changes were explored. The results indicate that there was a prolonged transition from shallow sea to lagoon before the formation of the Haixing wetland during the interval of 7500–4100 cal yr BP. The rate of watershed vegetation change increase significantly under the common influence of the 4.2 ka event and human activities, causing a regime shift in the mountain forest ecosystems and a decrease in landscape resilience. It was characterized by a substantial reduction in broad-leaved forests (from>30% to<5%), especially for Quercus (∼3%), which have not recovered to pre-event levels since the end of the 4.2 ka event. Since 3500 cal yr BP, the Haixing area was completely detached from the influence of the Bohai Sea, forming freshwater wetlands. The local vegetation rapidly shifted from alkali-tolerant communities that followed the sea retreat to freshwater marsh plant communities. During 2000–1100 cal yr BP, under the strong impact of human activities, the succession of forest and grassland communities in the basin became more frequent. The area of coastal salt marshes expanded, with salt-tolerant plant communities taking the absolute advantage. The wetland vegetation landscape became closer to the modern appearance. Overall, our study provides new evidence for understanding the rapid evolution of coastal ecosystems in East Asia influenced by a combination of climate, hydrology and humans. It will help guide the coastal regions in facing the challenges of future global climate changes.

Deteriorating wintertime habitat conditions for waterfowls in Caizi Lake, China: Drivers and adaptive measures

China has made enormous strides to achieve high-quality development and biodiversity conservation, and the establishment of nature-protected areas is one of the essential initiatives. Caizi Lake involves a natural reserve and two national wetland parks, accommodating winter migratory waterfowl over the middle and lower Yangtze River basin in China. However, the water transfer from the Yangtze River to the Huai River (YR-HR water transfer) has modified the winter hydrological conditions of Caizi Lake, negatively affecting wintertime waterfowl habitats. Hence, conserving wintertime waterfowl habitats necessitates knowledge of the dynamical mechanisms behind the impacts of YR-HR water transfer on wintertime waterfowl habitats and adaptive measures. Here we developed a machine learning model, the normalized difference vegetation index, and on-spot observatory datasets such as the spatial distribution of waterfowl species and underwater topography of Caizi Lake. We found that the rising winter water level of Caizi Lake encroaches on winter waterfowl habitat with extremely high suitability. Meanwhile, rising water levels reduced waterfowl food sources. Thus, rising water levels due to YR-HR water transfer deteriorated waterfowl living conditions over Caizi Lake. Therefore, we proposed adaptive measures to alleviate these negative effects, such as water level regulation, artificial feeding of waterfowls, restoration and reconstruction of contiguous mudflats, grass flats. This study highlights human interferences with waterfowl habitats, necessitating biodiversity conservation at regional scales.

A study on the response of waterbird diversity to habitat changes caused by ecological engineering construction

Wetland degradation is a major factor in the decline of biodiversity. Ecological engineering construction efforts, such as water diversion, have been the main method of wetland restoration. To reveal the effects of biodiversity conservation and ecological engineering construction in the semiarid regions of China, waterbird surveys were carried out 2 years before and 8 years after the construction of the ecological engineering project discussed in this study. The relationships among waterbirds and habitat landscape patterns, hydrology and vegetation conditions were analyzed. The impacts of ecological engineering on habitats and waterbird diversity were revealed. The results showed that (1) there were significant changes in land use, hydrological distributions and vegetation cover in the study area before and after the construction of the ecological project. The quality of waterbird habitats after the construction project was better than that before construction. However, there were fluctuating conditions. (2) The areas of water bodies and marshes were positively correlated with the number and diversity of waterbirds. However, increases in arable land, forestland, grassland and saline land can stress rare waterbirds. Changes in water levels, water body areas and vegetation cover in the conservation area all directly affect the availability of waterbird habitats, which can affect waterbird diversity. The wetland water level is the most important impact factor. (3) The annual water diversion volume in the study area is 5.00 × 107 m3. When the water level is maintained at approximately 1.5-2.5m, the number of waterbirds remains stable. This study can provide scientific guidance and a methodological basis for the construction of ecological projects with waterbirds as protected targets.

Assessing the potential long-term effects of sea-level rise on salt marsh’s coastal protective capacity under different climate pathway scenarios

Salt marshes act as natural barriers that reduce wave energy during storm events and help protect coastal communities located in low-lying areas. This ecosystem can be an important asset for climate adaptation due to its particular capability of vertically accrete to adjust to long-term changes in water levels. Therefore, understanding marsh protection benefits thresholds in the face of sea-level rise (SLR) is important for planning future climate adaptation. In this context, the main goal of this manuscript is to examine how the storm protection benefits provided by salt marshes might evolve under SLR projections with different probability levels and emission pathways. In this study, a modeling framework that employs marsh migration predictions from the Sea Level Affecting Marshes Model (SLAMM) as parameterization into a hydrodynamic and wave model (ADCIRC + SWAN) was utilized to explicitly represent wave attenuation by vegetation under storm surge conditions. SLAMM predictions indicate that the SLR scenario, a combination of probability level and emission pathways, plays a substantial role in determining future marsh migration or marsh area loss. For example, results based on the 50% probability, stabilized emissions scenario show an increase of 45% in the marsh area on Maryland’s Lower Eastern Shore by 2100, whereas Dorchester County alone could experience a 75% reduction in total salt marsh areas by 2100 under the 1% probability, growing emissions scenario. ADCIRC + SWAN results using SLAMM land cover and elevation outputs indicate that distinct temporal thresholds emerge where marsh extent sharply decreases and wave heights increase, especially after 2050, and exacerbates further after 2080. These findings can be utilized for guiding environmental policies and to aid informed decisions and actions in response to SLR-driven environmental changes.

Understanding Climate Change and Anthropogenic Impacts on the Salinization of Low‐Lying Coastal Groundwater Systems

AbstractFresh coastal groundwater is a valuable water resource of global significance, but its quality is threatened by saltwater intrusion. Excessive groundwater abstraction, sea‐level rise (SLR), land subsidence and other climate‐related factors are expected to accelerate this process in the future. The objective of this study is to (a) quantify the impact of projected climate change and (b) explore the role of individual hydrogeological boundaries on groundwater salinization of low‐lying coastal groundwater systems until 2100 CE. We employ numerical density‐dependent groundwater flow and salt transport modeling for this purpose, using Northwestern Germany as a case. Separate model variants are constructed and forced with climate data, that is, projected SLR and groundwater recharge, as well as likely ranges of other hydrogeological boundaries, including land subsidence, abstraction rates and drain levels. We find that autonomous salinization in the marsh areas, resulting from non‐equilibrium of the present‐day groundwater salinity distribution with current boundary conditions, is responsible for &gt;50% of the salinization increase until 2100 CE. Sea‐level rise, land subsidence and drain levels are the other major factors controlling salinization. We further show that salinization of the water resources is a potential threat to coastal water users, including water suppliers and the agrarian sector, as well as coastal ecosystems. Regional‐scale uplifting of drain levels is identified as an efficient measure to mitigate salinization of deep and shallow groundwater in the future. The presented modeling approach highlights the consequences of climate change and anthropogenic impacts for coastal salinization, supporting the timely development of mitigation strategies.

Centennial Changes of Salt Marsh Area in Coastal Georgia (USA) Related to Large-Scale Sediment Dynamics by River, Waves, and Tides

Marsh lateral expansion and retreat are often attributed to sediment availability, but a causal link is difficult to establish. To shed light on this problem, we analyzed changes in salt marsh area along the ~ 200-km-long Georgia coast (USA) from the 1850s to 2010s in relation to total suspended sediment (TSS) and to proxies for river sediment input and local sediment resuspension. Marsh area is characterized by large gains and losses (up to 200 m2/m/yr), but relatively small net change (-50 to 50 m2/m/yr or -0.1 to 0.1%/yr). This has resulted in a general loss of marsh area, except close to the mouths of major rivers, where there is net gain. Net expansion rates decreased in the Savannah Estuary but increased in the Altamaha Estuary from the 1850s–1930s period to the 1930s–2010s period, which are consistent with observed decreases and likely increases in sediment discharge in the two estuaries, respectively. To explain the spatial patterns in the 1930s–2010s marsh area change, we estimated TSS from satellite measurements (2003 to 2020). Along the northern part of the Georgia coast, net marsh gain is positively correlated to the average TSS within the estuarine region. However, this correlation breaks down in more southern areas (Cumberland Sound). Coast-wide, there is a better correlation between TSS associated with new input from the rivers, estimated as the TSS difference between high-discharge (Jan–Mar) and low-discharge (Sept–Nov) months. To identify the effect of wave resuspension in the nearshore, we consider the TSS difference between high-wave, low-discharge (Sept–Nov) and low-wave, low-discharge periods (Jun–Aug). Wave resuspension is relatively uniform along the coast and does not explain spatial patterns of marsh area change. Sediment input from the nearshore is likely contributing to the estuarine sediment budget in Georgia, but it is not sufficient to prevent marsh lateral retreat. To identify the role of tidal resuspension and advection, we consider differences in TSS between low and high tide. This differential is relatively constant along most of the coast, but it is much lower in the southern part of the coast, suggesting a lower tidal action in this region. Sediment resuspended by tides is likely originating from internal recycling (i.e., erosion) within the estuary, and thus does not contribute to marsh lateral expansion. The proposed approach to partition TSS is a general demonstration and could be applied to other coastal regions.

Marsh decrease was much faster than the water increase among the Yellow River Source wetlands during 1986–2022

Wetlands are valuable and sensitive ecosystems that make them imperative to tracking the dynamics in their extent for sustainable management under global warming. Here we focused on the Yellow River Source (YRS) wetlands, which is renowned for hosting one of the world's largest plateau peat bog, unfortunately, it had experienced sharp degradation, threatening the safety of water supply for approximately 110 million people of the lower Yellow River basin. However, the lack of long-term, dense time-series data makes it challenging to assess its evolution trends and driving factors. Therefore, we developed a decision tree sample migration method based on Euclidean distance and Land Surface Water Index, and successfully generated annual wetland mapping of YRS from 1986 to 2022 by utilizing the Landsat 5/7/8 datasets and Random Forest method. The average sample migration rate was 89.21 %, with an average overall accuracy of 95.49 %. We observed that the marsh area decreased by 2031 km2, marking a decline of 12.98 %, while the water area increased by 710 km2 (31.24 %) compared to 1986. Spatially, 10.96 % of marsh composition presents significant (P < 0.05) decline trend, which are mainly converted to grass (86 %), followed by impervious (10 %). There were 6.69 % of water composition showing significant (P < 0.05) increase trend, which are mainly sourced from impervious (82 %) and marsh (12 %). Grazing activities were more important driving forces than climate change for marsh degradation, while the water expansion was associated with recent rising temperature in YRS. The sample migration method is proved to be feasible, robust, and effective for long-term wetland mapping. We suggest that wetland decision-makers need to focus on marsh degradation and reduce grazing intensity, so that fostering the sustainable and healthy wetlands in the Qinghai-Tibetan Plateau.

Quantifying spatiotemporal dynamics in the Kolonnawa marsh of Colombo, Sri Lanka.

Kolonnawa marsh (KM) is an important wetland ecosystem in Colombo district, Sri Lanka that provides essential ecosystem services, and has undergone significant changes over recent decades due to continuous exploitation and reclamation. The values of wetlands are disregarded by decision-makers, despite the fact that they are crucial for improving the quality of water and offer chances for relaxation and amusement in metropolitan areas. Underestimation of the value of wetlands contributes to their continuing deterioration and inevitable loss. Investigating the changes in wetlands can provide crucial information for decision-making. This study aimed to monitor the spatiotemporal land-cover dynamics of KM with the prospect prediction as reduced total extent of KM gradually with time and marsh area being transformed into terrestrial vegetation with time. The collective images from Google Earth (2000 to 2021) and drone data (2022) were analyzed with the GIS application. Subsequently, 50-m2 grid squares with unique cell IDs are designed to link among land cover maps for spatiotemporal land-cover change analysis. Then, we calculate land cover category: surface water, marsh, and terrestrial vegetation proportions for each map in 50-m2 grid cells. Statistical comparison of the land cover changes in grid square cells shows that each land cover category has significant change with the time. The results showed that the reduction of KM marsh resulting in land cover changes has a positive implication on wetland degradation. Thus, interventions should be made for the restoration and sustainable management of KM.

Geological environmental study of Al-Dalmaj marsh area: Review

Geological environmental study of Al-Dalmaj marsh area: Review

Spatio-temporal variations and influencing factors analysis of coastal wetlands in Tianjin, China

Coastal wetlands are one of the world’s most threatened ecosystems and the influences of climate change and anthropogenic factors on changes in coastal wetland distribution have been the subject of active research in recent years. However, the multi-year intergenerational trends in coastal wetland areas, and the factors influencing them in China have not been fully studied using geographic spatial data during the past 30 years. The relative contributions of climate change and anthropogenic factors to spatio-temporal variations in coastal wetland area also remain to be described. In this study, we discuss changes in the coastal wetland areas and the reasons behind them in Tianjin, which is one of China’s fastest developing regions, using remote sensing and geographic information system technology, Pearson correlation analysis, the relative weight method and the land expansion extraction module, the land expansion analysis strategy (LEAS) model of the Patch-generated Land Use Simulation (PLUS) model. The results showed that the total wetland area declined from 2233.59 km2 in 1984 to 1742.73 km2 in 2020. We conclude that the expansion of non-wetland land types is the main driver of natural wetland area decrease, with 830.86 km2 of natural wetlands having been converted to non-wetlands during this period. The large areas of shallow water and tidal marsh that have been converted to construction and bare land particularly emphasize the primary importance of urbanization and coastal reclamation in driving wetland reduction. The results showed that the temporal variation of natural wetlands area was correlated with population density (PD), total gross domestic product (GDP), annual mean temperature (AMT), average relative humidity (ARH), and primary (PI), secondary (SI), and tertiary industrial development (TI). PD, PI, TI, GDP, SI, AMT, and ARH contributed to 24.47 %, 18.21 %, 15.74 %, 14.16 %, 12.77 %, 7.09 %, and 4.86 % of the wetland area decrease, respectively. PD, distance to settlements (DS), distance to railways (DRW), AMT, distance to rivers (DR), and GDP contributed 17.61 %, 14.27 %, 13.83 %, 13.62 %, 12.07 %, and 10.92 % of the spatial variations of natural wetland area, respectively, which showing the predominant effects of anthropogenic variables on the spatio-temporal natural wetland areas. Our results are valuable in identifying the dynamic spatio-temporal variations in coastal wetlands to improve our understanding of the impacts of climate change and human activities on coastal wetlands to help in the future protection and restoration of wetlands.

Monitoring of mammal and bird species in an urban ecological park using environmental DNA metabarcoding

Monitoring species distribution and abundance accurately and efficiently are vital for conservation efforts. Next-generation sequencing and DNA metabarcoding using environmental DNA (eDNA) allow for the simultaneous identification of multiple species in one sample, enabling swift biodiversity assessment in complex ecosystems. However, most eDNA studies focus on aquatic organisms and ecosystems.This study’s main objective was to use eDNA metabarcoding to monitor mammal and bird species in an urban ecological park. The chosen study site was Gildong Ecological Park, Seoul, South Korea, with a total area of 80,000 m² divided into three marsh area, a forested mountain area, and a rural experience learning center. Water sampling occurred five times from August to September, yielding 65 samples from three park sections. We employed MiMammal and MiBird primers targeting mitochondrial 12 S to investigate mammals and birds, serving as pivotal biological indicators within urban ecosystems.Metabarcoding revealed the presence of 73% (11/15) and 67% (represented 67% of the total 6268 individual) of the dominant mammalian and avian species, respectively, known to inhabit the park, compared to the results of traditional surveys. The mountain samples (1.51) and marsh samples (2.32) had significantly different median read counts when including all species; however, the same comparison within each taxonomic group yielded no statistically significant differences. Though we detected species differences using eDNA across summer, autumn, and winter monitoring, no statistically significant differences were found among seasons within the park. However, the park’s area is relatively small for detecting variations in eDNA. This might be because there is a lot of animal activity throughout the study site and/or a limited influence of microhabitats. These results could provide valuable insights for using eDNA to monitor animals in urban ecological parks.

Coastal Zone Management in Response to Sea Level Rise in the 21st Century: A Study from Hurst Spit to Lymington, South England

This study examines the coastal region spanning from Hurst Spit to the mouth of the Lymington River along the Western Solent coast in Hampshire, South England. The area comprises critical habitats for international bird species on the seaward side and is protected by a seawall on the landward side. Rising sea levels pose a significant threat to this area, including habitat loss and potential seawall breaches. To address the uncertainty in sea level rise projections for the 21st century, this study utilises data processing in ArcGIS, including LiDAR data, tidal data, and sea level rise projections. It adopts contingency allowances for sea level rise, resulting in a projected 0.89 metre by 2100. Analysis reveals a significant transformation in habitat distribution, with standing water and mudflats expanding while salt marshes and dry land areas diminish. Salt marsh areas are projected to contract by 64.6%, with the pioneer salt marsh facing the greatest loss. The report recommends a proactive approach, including realigning the seawall in vulnerable areas, allowing for the creation of new salt marshes. This managed intervention strategy can reduce habitat loss to approximately 17.43%, mitigating the potential ecological and human habitat impacts of rising sea levels in that region.

Application of remote sensing methods for monitoring extent, condition and blue carbon storage in salt marshes

Salt marshes are fragile coastal ecosystems that provide a wide range of ecosystem services, including carbon sequestration and storage. Despite the importance of salt marshes for blue carbon sequestration, few studies have been done on blue carbon monitoring using satellite remote sensing techniques. This study arose to fill this knowledge gap, and aimed to determine the amount of blue carbon sequestered in salt marshes by analyzing the particular case of the Pancas salt marsh (Tagus Estuary, Portugal). To achieve this, the extent and condition of the Pancas salt marsh were assessed using remote sensing methods, by establishing a methodology that effectively identified and validated its extent based on Sentinel-2 imagery from 2016 to 2022. This method involves generating a reference salt marsh extent map followed by mapping salt marsh extent through four Vegetation Indices (VI) from Sentinel-2 data to compare and thus validate the salt marsh extent based on the information provided by the satellite. Considering the extent of the salt marsh and the changes it has undergone over the 7 years studied, together with reference values for sequestered carbon in the salt marsh sediments, approximate values for sequestered blue carbon were determined. The results highlighted the validation of Normalised Difference Vegetation Index (NDVI) as the best-performing VI for this study and as a proxy for the condition of the salt marsh in terms of the spatial and temporal distribution of its aboveground biomass. It was also verified that the salt marsh expanded its frontal region by 0.22 km2 between 2016 and 2022, while certain areas of high marsh have suffered dieback. Concerning sequestered carbon, an increase of 508.2 tonnes since 2016 was quantified, corresponding to 66500 tonnes of blue carbon stored for 2022. Our study revealed the intrinsic relationship between the extent of a salt marsh and its carbon sequestration capacity highlighting the importance of future application of more remote sensing techniques, to emphasize the significant role of these ecosystems in carbon sequestration and climate change mitigation.

Diapiric Structures in the Tinto River Estuary (SW Spain) Caused by Artificial Load of an Industrial Stockpile

The mouth of the Tinto River is located on the southwest coast of the Iberian Peninsula in the northwest of the Gulf of Cadiz. The river flows into an estuarine system shared with the Odiel River, commonly known as the “Ría de Huelva”. In the 1960s, a wide area of ancient salt marshes was transformed by a stockpile of industrial wastes of phosphogypsum, reaching a height of 35 m above the level of the salt marsh at its highest point. Two surveys using high-resolution seismic reflection in conjunction with a parametric profiler were carried out in 2016 and 2018. The purpose of these geophysical studies was the realization of a 3D model of the sedimentary units constituting the most recent filling of the estuary. The records present abundant extrusion structures located on the margins of the waste stockpiles, which break the visible stratification of the surficial units of the estuary. In some sectors, these structures have reached the estuarine surface and have, therefore, a morphological expression on the estuarine floor. The origin of these structures is interpreted as a vertical escape of fluidized sediments from lower units caused by overpressure from stacking.

Changes in diversity of marsh plant communities under shrub encroachment in Sanjiang Plain and their soil control factors

In this study, we explored the changes in plant community diversity and their relationship with soil factors under shrub encroachment pressure by selecting four marsh areas in Sanjiang Plain with different degrees of shrub cover (a, 0≤a≤100%), including marsh with no shrub encroachment (a=0), light shrub encroachment (0<a≤30%), medium shrub encroachment (30%<a≤70%), and heavy shrub encroachment (70%<a≤100%). The results showed that shrub encroachment was the main reason for the heterogeneity of plant community composition in marsh. With shrub encroachment, the dominant species Deyeuxia angustifolia was replaced by Spiraea salicifolia, whereas Carex schmidtii disappeared. However, the importance values of Sanguisorba tenuifolia and Stellaria radians in the community significantly increased by 0.8- and 9.0-fold, respectively. Shrub encroachment resulted in changes of plant community diversity in marsh. The highest α and β diversity in plant community were observed under light shrub encroachment area, whereas there were no significant differences in Shannon and Simpson indices between heavy and no shrub encroachment areas, despite their similarity in plant community composition was the lowest. All the studied soil factors were significantly affected by shrub encroachment, except total phosphorus. There were significant reductions in soil moisture, organic carbon, and total nitrogen in heavy marsh shrub encroachment area by 32.6%, 69.3%, and 66.1%, respectively compared with that in no marsh shrub encroachment area, whereas soil total potassium and total magnesium significantly increased by 33.8% and 40.6%, respectively. Results of redundancy analysis showed that soil organic carbon, moisture content, total nitrogen, and N:P were the main factors controlling the diversity changes of marsh plant community under shrub encroachment pressure.

Harmonization of Nordic coastal marsh habitat classification benefits conservation and management

Coastal marshes are productive and diverse habitats that act as essential linkages between marine and terrestrial ecosystems. Although the Nordic region comprises diverse, unique marsh habitats along the Baltic coast and the Atlantic coast of Norway, they are not widely recognized as coastal marshes, e.g., salt marshes in other parts of the world. This may be partly due to inconsistency in habitat classification, use of terminology, and the heterogeneity of these habitats across the region, which limit overviews of their ecology, distribution, and management. Here, we aim to improve the basis for assessments of Nordic coastal marshes by providing an overview of terminology, distribution, area, and management practices of these habitats across the region. We use the general term coastal marsh to cover the variety of habitat types in the study area, which are covered mainly by the European Union's (EU's) Habitats Directive Annex I habitat classes 1310 Salicornia and other annuals colonizing mud and sand, 1320 Spartina swards (Spartinion maritimae), 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae), and 1630 Boreal Baltic coastal meadows. Based on input from national environmental officers, an expert survey, a workshop, and reviewing environmental databases, we compiled a comprehensive database on coastal marsh habitats regarding their distribution, classification, conservation status, management, and monitoring practices in four Nordic countries (Denmark, Finland, Norway, Sweden) and Germany, covering wide environmental gradients in, e.g., salinity and tidal range. Overall, we found that the four Annex I classes cover an area of ∼900 km2 in the study region, one-fourth of the total area of these habitats in the EU, with an additional ∼450 km2 of other potential coastal marsh areas and 500 km2 of coastal reed beds. Beyond the variable terminology across the region, our study revealed a gap in the European habitat classification systems concerning the diversity of the Baltic Sea coastal marshes. Creating subtype(s) for the Annex I class 1630 would help to improve the conservation of the most threatened habitat types within the class. In addition, we found pronounced differences in monitoring and managing coastal marshes among countries, indicating that these important and diverse habitats between land and sea might receive insufficient attention and protection despite the multiple ecosystem services they provide. Coordinated harmonization of habitat classifications and monitoring across the Nordic countries could increase regional-scale coordination of the management of coastal marshes and facilitate comparative studies.

Demonstrating the effectiveness of open‐water wetlandscape restoration: lessons learned from South‐Eastern Europe

This paper evaluates the effectiveness of restoring open‐water area in a wetland via a geographical framework that goes from a general perspective to a detailed view. The methodology relies on diachronic cartography, remote sensing through Landsat satellite imagery validated by in situ hydrological data (2000–2022), and details from field work. We analyzed the water surface area of Comana freshwater marsh in Southern Romania. The water surface area recorded a statistical change point synchronous to the restoration actions. The water surface area increased due to restoration actions in 2011 and then became relatively stable. Post‐restoration, the mean monthly discharge of Neajlov River correlates statistically with the water surface area. The water has low depths in the marsh; yet, the area covered by vegetation appears to be stable. The persistence of the effects for over a decade recommends Comana Marsh as a demonstrative case study in South‐Eastern Europe and for further monitoring activities.

Forest cover and environment type shape functional diversity of insectivorous birds within the Brazilian Atlantic Forest

SummaryTropical insectivorous birds comprise a diverse group that has a distinct response to habitat degradation. However, knowledge on birds’ ecological functions and their large-scale functional responses to human impacts across various habitats is scarce. We sampled 22 1-km-radius buffer landscapes within the Cantareira-Mantiqueira region (south-east Brazil), including native forests, pastures and marshes, to assess how landscape and habitat characteristics might affect insectivorous birds within the Brazilian Atlantic Forest. We studied whether bird species and functional diversity might respond to habitat turnover and nestedness and to native forest cover using generalized linear mixed models. We found negative effects of increased native forest cover on functional diversity indices. Bird communities in pastures show more nestedness, whereas marsh areas exhibit higher turnover. Forest areas receive a balanced contribution from both nestedness and turnover. These results are attributable to the predominantly secondary growth and early successional stages of the native forest fragments in the region, emphasizing the connection between landscape characteristics, habitat types and bird functional diversity in the Brazilian Atlantic Forest.

Small Strain Shear Modulus of the Ljubljana Marsh Soil Measured with Resonant Column and Bender Elements under Isotropic and Anisotropic Stress Conditions

The increasing use of finite element analysis in modern infrastructure design emphasizes the importance of determining soil stiffness at small strains. This is usually represented by the normalized shear modulus degradation curve, which is crucial for accurate design. In the absence of specific measurements on the local soil, engineers often rely on empirical correlations and assume comparable behavior of soils with similar intrinsic properties. However, the application of this approach leads to uncertainties, especially for unique geological formations such as the soft cohesive soils of the Ljubljana Marsh. The main objective of this study was to determine the small strain shear modulus of Ljubljana Marsh soil with a plasticity index between 11 and 35%. Isotropic and anisotropic stress conditions were investigated as part of an extensive laboratory test program that included 45 bender element and 89 resonant column tests on 20 soil samples. By emphasizing the importance of measuring soil stiffness at small strains, this study not only provides reliable data for the development of the built environment in the Ljubljana Marsh and similar areas, but also underlines its necessity.

Testing strategies to enhance transplant success under stressful conditions at a tidal marsh restoration project

Tidal marsh restoration is becoming an increasingly common tool to plan for future sea level rise. Subsided marshes' elevation can be restored through sediment additions, which may necessitate the reestablishment of vegetation. Understanding key actions to increase vegetation cover at areas that remain persistently bare following elevation restoration is a critical component of a project's long‐term success. Dominant species can shape ecosystem function, as well as ameliorate stressful environments. We transplanted the dominant species, Salicornia pacifica, into bare areas of a restored tidal marsh in central California, United States, 3 years following a sediment addition. We tested salt hardening of plants before transplanting, targeted irrigation, transplant size, and planting configuration to identify management actions that could help vegetation persist in the most stressful areas of the high marsh. Weekly targeted irrigation until the first rains began was critical for small plant survivorship. We found that larger plants had increased survivorship and contributed higher amounts of growth and cover but did not facilitate the performance of nearby smaller plants. After 2 years, we determined that using lone, larger plants was more cost‐effective than multiple smaller plants at our tidal marsh. However, performance was highly site‐specific with dramatically less growth at a drier site with sandier soil. Our results highlight the importance of identifying site‐specific restoration strategies that either ameliorate or help plants tolerate stressful conditions, contributing to the continued success of tidal marsh restoration for climate resilience.