Wetlands

Taie Semiromi, Majid; Pätzig, Marlene; Merz, Christoph; Hayashi, Masaki

doi: 10.1007/s13157-025-01961-5pmid: N/A

The last glaciation period, known as the Wisconsin glaciation in North America and the Weichselian glaciation in North Central Europe (NCE), sculpted distinctive landscape features across these regions, including kettle holes in NCE and prairie potholes in the North America’s Prairie Pothole Region (PPR). These depressions, formed by retreating glaciers, hold significant hydrological and ecological importance, and conservation interest. The primary aim of this review article is to compare the similarities and differences between kettle holes in NCE and prairie potholes in the PPR, particularly concerning their ecohydrological characteristics, which have not been thoroughly compared or documented. By clarifying these distinctions, we can gain a better understanding of their unique features. This, in turn, enables wetland scientists to propose tailored management strategies to policymakers and decision-makers for conservation efforts. Our review explores, in particular, kettle holes/prairie potholes’ roles in water storage, nutrient cycling, and habitat provision. We also discuss the impact of anthropogenic activities, such as agricultural and land management practices, on the ecological integrity of these wetlands and propose strategies for their conservation and sustainable management. By elucidating the intricate interplay between geological history, hydrological processes, and ecological dynamics, this article provides valuable insights for researchers, policymakers, and conservation practitioners working towards the preservation of these globally significant wetland habitats. Our synthesis underscores the critical need for interdisciplinary research efforts and integrated management approaches to address the conservation challenges facing prairie potholes and kettle holes in the context of ongoing environmental changes and increasing human pressures.

Yan, Hua

doi: 10.1007/s13157-025-01974-0pmid: N/A

Wetlands provide essential ecological services, yet many degraded agricultural lands occupy former wetland areas, necessitating effective restoration strategies. Existing evaluation frameworks for restoration potential remain limited due to the absence of multidimensional indicators that integrate both biophysical conditions and socio-economic factors, leading to incomplete assessments of restoration feasibility. This study proposes a streamlined framework to assess the potential for converting agricultural land to wetlands in the southeastern United States, incorporating spatial analyses of land productivity, topographic moisture, hydrologic characteristics, disaster risk, and crop insurance indemnities. The results showed that areas with medium and high restoration potential accounted for 16.59% of the existing wetland area, highlighting significant opportunities for wetland restoration. Florida had the highest proportion of areas with medium and high restoration potential at 25.49%, followed by Mississippi with 15.27% and Alabama with 15.10%. A comparison with the Potential Wetland Areas (PWA) dataset revealed that many high restoration hotspots on low-productivity agricultural lands in Alabama were underestimated by 5.13% in the PWA. Analysis of the water quality dataset identified high-priority regions with degraded water quality and significant crop indemnities in western Mississippi, Tennessee, southeastern Georgia, and central Florida. These areas should be prioritized by environmental institutions for wetland restoration programs aimed at restoring ecological functions. This study offers a scientific foundation for improving wetland restoration strategies, contributing to the sustainability of agroecosystems.

Azzoug, Radia; Bentellis, Alima; Sahli, Leila; El-Hadef El-Okki, Mohamed; Angiolini, Claudia; Rached-Mosbah, Oualida

doi: 10.1007/s13157-025-01963-3pmid: N/A

Azlan-Hisham, Nurhidayah; Syafiq, Muhamad F.; Aqmal-Naser, Mohamad; Ahmad, Amirrudin

doi: 10.1007/s13157-025-01945-5pmid: N/A

The ichthyofauna of the Perlis River basin, a critical wetland-associated region in Malaysia, was last comprehensively studied over a decade ago. Fish assemblages in the lower reaches, floodplains, and associated wetland habitats remain insufficiently documented. This study sought to compare fish assemblages across three distinct habitats within the wetland integral to the basin’s ecosystem and expand checklist of freshwater fishes in Perlis River basin. A total of 58 species from 25 families were recorded during surveys conducted between January and September 2022 for Perlis River basin. Cyprinidae was the most abundant family (13 species), followed by Bagridae, Osphronemidae, and Channidae, with four species each. Species richness was highest for the upstream 1, followed by downstream, Timah-Tasoh Reservoir (TTR), and upstream 2. Fish assemblages varied significantly between habitats, forming distinct groups based on habitat types, as indicated by 2D-nMDS. The taxonomic compositions for 20 sites were relatively similar, except for four sites, which fell outside the funnel plot. The formation of the reservoir reduced native fish species richness and led to similar taxonomic composition, suggesting potential biotic homogenization within the fish community. Upcoming investigations are critical to better understand the role of wetland ecosystems and floodplains in conserving native fish diversity, sustainable fisheries purposes and mitigating the impacts of invasive species.

Beltman, Boudewijn; Held, Hanneke Den; Barendregt, Aat; Dorland, Edu

doi: 10.1007/s13157-025-01952-6pmid: N/A

A fen area north of Amsterdam used to be rich in plant species but changed into a monotonous acidic Sphagnum-Polytrichum-moss-layer over the last 50 years. Species loss was greatest after ca. 1975 and was attributed to acid rain, a big environmental problem at that time. We reviewed data over 1942–2010 to describe the succession and processes in this fen system. Acidic conditions were already present in 1942 and yet many red list species were present. Reconstructing chemical soil and water data indicated a gradual process of acidification in the subsoil, caused by increasing raft depth which enhanced the storage of acidic rainwater. Buffering capacity of the subsoil was consequently gradually depleted resulting in the loss of many (endangered) plant species. Changes in salinity or nutrient concentrations were considered of less importance to the succession of this fen system. Conservation and restoration of biodiversity in these wetlands, as obliged by the Habitat- Directive, is impossible unless the succession can start again from open water facilitating plant species of high nature value in the long term.

Martínez-Fornos, Gonzalo; Talone, Marco; Cobos, Joaquín; Bustamante, Javier; Díaz-Delgado, Ricardo

doi: 10.1007/s13157-025-01962-4pmid: N/A

The potential of applying a semi-automatic remote-sensing system for the early detection of cyanobacterial bloom was evaluated. The system combines in-situ hyper-spectral measurements collected using a set of above-water TriOS RAMSES radiometers with satellite data provided by the Multispectral Instrument onboard Copernicus Sentinel-2. A set of consolidated indices related to the concentration of cyanobacteria is tested and verified against in situ measurements collected between November 2020 and December 2023 in the Spanish National Park of Doñana, in the southwest of the Iberian Peninsula. Results indicate that in situ hyper-spectral observations allow the rapid detection of both phytoplankton bulk biomass and cyanobacteria. Regarding satellite observations, while sensitive to the sole bulk phytoplankton biomass, they prove to be extremely useful for the spatial characterization of the water body, thus allowing a more robust assessment of the general ecosystem status. Finally, a specific automatic processing chain and a graphical user interface have been implemented to ensure the easy exploitation of the radiometric measurements and their use by the National Park Monitoring Team.

Sepúlveda-Lozada, Alejandra; Castillo, María Mercedes; Zarza, Eugenia; Guillén-Navarro, Karina; Diego-García, Elia; Jarquín-Sánchez, Aarón; Rodiles-Hernández, Rocío

doi: 10.1007/s13157-025-01964-2pmid: N/A

Despite the key role of bacteriobenthos in the biogeochemistry of coastal wetlands, the drivers controlling their diversity, distribution, and assembly at the freshwater-seawater transition remain unclear, particularly in tropical regions. Based on 16S rRNA gene amplicon sequences, we analyzed how benthic bacterial communities in floodplain lakes change along a salinity gradient in the Grijalva-Usumacinta deltaic plain (GUd) in southeast Mexico. Diversity was significantly higher in the low salinity portion of the delta and decreased towards higher salinities. However, lower diversity was also observed in a freshwater lake with the highest water chlorophyll a concentration, presumably indicating the detrimental role of eutrophication on diversity. Most bacterial sequences were assigned to Proteobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, and Firmicutes. Among Proteobacteria, Gammaproteobacteria (including former Betaproteobacteria) dominated in low salinity and Alphaproteobacteria in higher salinity. The most abundant members of these groups participate in the biogeochemical cycles of major elements. Others are commonly associated with sewage, heavy metals, and hydrocarbons. Our results support the hypothesis that there are spatial changes in the bacteriobenthos structure of GUd floodplain lakes, reflecting changes in site conditions along the salinity gradient. As in other coastal regions, salinity featured as the main driver of bacterial diversity and composition, although nutrient availability also played an important structuring role. As coastal wetlands face multiple human stressors, such as saltwater intrusion, unsustainable use, and pollution that may cascade into significant ecosystem changes, research on bacterial communities is essential for gaining a deeper understanding of the complex dynamics of these wetlands.

Cornwell, Jeffrey C.; Owens, Michael S.; Staver, Lorie W.; Stevenson, John Court

doi: 10.1007/s13157-025-01968-ypmid: N/A

The trajectory of marsh development in created marshes is highly variable, with development of plant productivity, organic matter storage and nutrient cycling important for achieving restoration goals. The paradigm of slow development of biogeochemical processes was examined for nutrient and gas exchange in marshes created from materials dredged from the upper Chesapeake Bay. At Poplar Island, marshes created from fine-grained sediments benefit from high soil nutrient concentrations and rapid growth of high and low marsh plant species. Marsh development occurred over a number of years, with multiple individual wetland segments, or “cells”, providing a broad view of the pace of wetland development. Using flooded cores, the fluxes of O2, N2 and nutrients were determined under both dark and illuminated incubation conditions. The rapid development of edaphic algal productivity in marsh and creek environments produced surficial organic matter enrichments that accelerated nutrient cycling processes. Comparisons of young (< 2 y) and old (5–7 y) wetland cells showed that overall rates of soil respiration, photosynthesis, and denitrification were similar, suggesting rapid development of biogeochemical cycles. Rates of marsh and creek denitrification averaged 11–14 g N m− 2 y− 1, larger than most published rates in other wetland restoration projects. These data suggest that microbial denitrification occurs at high rates early in the development of the wetlands, likely a function of nutrient-enriched substrate and a marsh surface with minimal vertical drainage.

Delaney, John T.; Van Appledorn, Molly; De Jager, Nathan R.; Bouska, Kristen L.; Rohweder, Jason J.

doi: 10.1007/s13157-025-01956-2pmid: N/A

Information on the favorable conditions for invasive species as well as potential constraints to their distribution can be valuable for management efforts. We used a niche modeling approach to analyze the patterns of species distributions along gradients of hypothesized influential environmental variables. Many ecological datasets may have incomplete coverage across the environmental gradients, infrequent sampling under some conditions, insufficient time for an invasive species to occupy all sites, and complex interactions among environmental variables (measured or unmeasured) that may result in species response curves that are difficult to interpret and may be ecologically misleading. To ensure the model and species response curves aligned with ecological niche theory, shape constraints were imposed to guarantee relationships follow a unimodal distribution to reflect the fundamental niche (where a species could occur). We compared a shape-constrained model to an unconstrained model and interpreted the species response curves from the constrained model to better characterize the ecological niche of reed canarygrass in floodplain forests of the Upper Mississippi River, USA. We found the probability of reed canarygrass occurrence decreases with increasing tree canopy cover, tree species richness, distance from forest edge, distance from invaded wet meadows, and island isolation. Probability of reed canarygrass presence exhibited bell-shaped curves in response to hydrology (inundation depth, frequency, and duration) and forest stress metrics indicating an optimum with less favorable conditions on either end of the ecological gradients. This information could be used to prioritize restoration efforts and enhance landcover change research in forested floodplains.

Ayassamy, Prisca

doi: 10.1007/s13157-025-01971-3pmid: N/A

Mangroves are increasingly recognized as effective Nature-Based Solutions (NBS) for enhancing climate resilience in coastal regions; however, their efficacy and the enabling conditions necessary for successful implementation remain inconsistently documented. This systematic review follows PRISMA guidelines and synthesizes findings from 13 peer-reviewed articles published between 2013 and 2023. Key findings reveal that mangroves mitigate annual flood damages by up to $65 billion globally while also delivering co-benefits such as improved water quality, enhanced fisheries, and increased recreational opportunities. The effectiveness of these interventions is strongly shaped by governance structures, especially adaptive and polycentric frameworks, and financial accessibility, which remains a predominant constraint, particularly in low-income tropical nations. Based on the analysis, four strategic interventions are proposed: (i) leveraging ecotourism to internalize local socio-economic benefits; (ii) framing large-scale mangrove restoration as an NBS to attract climate financing; (iii) creating blue-carbon instruments embedded within adaptive governance systems; and (iv) initiating community-level social resilience programs. This review calls for greater emphasis on multilingual research dissemination, comprehensive economic valuation, and equitable benefit-sharing models to fully realize the potential of mangroves as NBS for climate adaptation.