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Estuarine wetlands provide a wide range of ecosystem functions, including carbon storage, biodiversity maintenance, and shoreline protection, and have human recreational value. In recent years, over half of China’s estuarine wetlands have been lost due to natural or anthropogenic stresses. Estuarine wetlands are facing great challenges regarding their protection, restoration and management. China’s 18,436 km of coastline support nearly half of its human population and 45 of its 60 major cities. It sustains over 28,000 species, and processes the outflow from seven of its nine major rivers. Rapid economic development in China is a cause of coastal degradation. In an attempt to mitigate habitat loss, over 1000 coastal restoration projects have been conducted in China in the past few decades. Great achievements have been made in the wetland restoration projects. In the future, biological combined restoration technology will become increasingly popular in China. [ABSTRACT FROM AUTHOR]

The high-intensity development of a city encroaches on the ecological land, such as lakes, rivers, and forests, which changes the stable land relationship, resulting in ecological security problems, such as regional waterlogging and a decline in biodiversity. Identifying urban ecological systems and constructing ecological security patterns (ESP) are of great importance for urban ecological protection and spatial planning. The complexity of the ecological environment in landscape cities makes them more difficult for planning and construction than in plain cities. Additionally, they are more susceptible to torrential rains, mountain torrents, and river tides in the process of urbanization. This study introduced the functional wetland theory into the construction of the ESP and obtained a new set of methods for landscape cities. Based on the functional wetland theory, the “patch-corridor-matrix” model was used to combine the geographic information system (GIS) runoff and catchment analysis with the MSPA-MCR ecological corridor construction method to form a new wetland and habitat network by coupling the two together. Additionally, construction principles of protection priority, maximization of ecological benefits, guarantee of connectivity, and targeted design to guide the construction of landscape cities were put forward. This study takes the central urban area of Fuzhou as an example to show the application path of this method.

The high Andean arid plateau extends through Peru, Argentina, Bolivia, and Chile. Within the desert matrix, basins contain wetlands that provide essential resources for human activity, and habitat for biodiversity highly adapted to extreme temperatures, altitudes, and salinity gradients. In these waterscapes, the water balance, even without human intervention, is negative and their unique biodiversity and lifeways are now confronted with an unprecedented level of development from lithium mining for rechargeable batteries. The "lithium triangle" coincides with the areas of highest abundance of the altiplano's iconic flamingos. Flamingos are an ideal flagship for conservation because of the landscape scale at which they use wetlands, and Network of Wetlands for Flamingo Conservation, which implies the sustainable use of these wetlands, can be invoked to determine priority conservation actions. Since 2016, mining exploration has increased throughout the region, most notably in Argentina. A review of the Environmental Impact Reports (IIAs) for projects in Catamarca, Argentina, shows that they do not comply with national guidelines: they do not adequately address water budgets, consider protected area status, engage local communities, or consider cumulative and synergistic impacts. While the transition to "green" energy sources holds the promise of mitigating the negative impacts of traditional energy sources responsible for climate change, a truly sustainable energy sector would consider the full life cycle of the battery ("cradle-to-grave"), the social and environmental impacts of mining, and the feedback processes across the coupled socioecological systems, from raw material mining through production, use, recycling, and disposal. [ABSTRACT FROM AUTHOR]

The abundant estuarine wetlands supported by the complex river network in the Pearl River Delta are under intense anthropogenic influence, which threatens the local ecosystem. This paper examines the benthic macroinvertebrate diversity and abundance within the Pearl River Estuary through a field study. Fieldwork, based on the integral index of connectivity (IIC) of the wetland network, was carried out in the Pearl River Estuary. The responses of macroinvertebrate metrics to the integral connectivity gradient in the wetland network were examined. Statistical analyses (CCA) revealed that the benthic abundance in high-hydrological-connectivity riverine habitats was clearly distinct from that in low-connectivity habitats. Statistical analysis demonstrated that the diversity and abundance of the macrobenthos populations were determined by the integral connectivity of the wetland network. A non-linear model was developed to depict the relationship between macroinvertebrate diversity and network connectivity. Thus, conservation efforts in estuarine wetlands should focus on the macroinvertebrate diversity response in wetland patches with specific connectivity characteristics in the wetland network of the Pearl River Delta. [ABSTRACT FROM AUTHOR]

Estuarine wetlands are valuable ecosystems of coastal zones. Traditionally, wetlands are preserved by establishing nature reserves within them. However, the driving forces of estuarine wetland degradation change at different temporal and spatial scales, rendering it necessary to evaluate the entire river–delta–wetland system. We analyzed the links between management of the Yellow River (YR) and estuarine wetland conservation in the Yellow River Delta (YRD). We measured changes in river runoff and sediment discharge from 1950, and spatial changes in the tail channels from 1855. Changes in the wetland areas of the entire delta, the natural reserves, and the river buffer areas were calculated. Finally, the effects of ecological water supplementation of the YR, mandated in 2008 by the Chinese government to protect estuarine wetlands, were also analyzed. The results indicated that not only the reductions in river runoff and sediment discharge, but also shifts in the tail channels, influenced estuarine wetlands. In addition, ecological water supplementation from the YR have improved wetland health. We suggest that increasing the connectivity between old and new rivers is important to improve the integrity of estuarine wetland ecosystems. Linking river management to estuarine wetland conservation would aid in the planning and improvement of the wetland network in the delta. [ABSTRACT FROM AUTHOR]

The management of population size and genetic diversity in fragmented landscapes is the central issue in conservation biology. Functional connectivity between remnant habitat patches affects these parameters. However, the functional connectivity for genetic diversity would be characterised by a greater spatial scale than population size even within the same habitat network. The reason for this difference is that while dispersal frequency generally decreases with increasing distance, only a few immigrants may effectively contribute to gene flow, whereas a certain number of dispersers may be required to influence population abundance., Here, we investigated the effects of habitat network structures on population abundance and genetic diversity of the ninespine stickleback, Pungitius pungitius, in remnant wetland ponds in northern Japan. We tested (i) whether both population abundance and genetic diversity are positively related not only to habitat size but also to connectivity and (ii) whether the dispersal effect extends to greater spatial scales in genetic diversity than in population size., We employed a graph theoretical index to measure the degree of pond connectivity. This index can evaluate the connectivity threshold distance above which individuals cannot disperse and clarify the difference in the spatial scale of effective dispersal between population abundance and genetic diversity., Pond connectivity significantly affected the spatial variation of both population abundance and genetic diversity. In contrast, pond size was related only to population abundance. As we predicted, the connectivity threshold distance for genetic diversity was more than two times greater than that for population abundance (12.5 km versus 5 km, respectively)., Our findings indicate that the landscape managers should consider various spatial scales as a conservation unit for the management of a habitat network in accordance with the conservation targets that they establish. We also found that small artificial agricultural ditches and streams may play important roles in sustaining the population networks of wetland organisms. [ABSTRACT FROM AUTHOR]

The notion that the conservation of wetlands in the world is too limited has gained a universal consensus because of the conflicts between their great value and the drastic decline in their quantity and quality. To mitigate these conflicts, ecological networks have integrated the hydrologic and biological connectivity of ecosystems. The basic elements of ecological networks, patches, and corridors, have been extracted to reflect the attributes of the hydrologic and biological connectivity of ecosystems. This paper reviews recent applications of network approaches to ecological conservation, focusing on their application in wetland ecosystems, and proposing a new perspective for wetland conservation. This review is limited to four aspects: first, the linkages between wetlands and ecological networks are determined by reviewing the development both of them; second, the two types of connectivity and their application that can be obtained from graphs or network models are discussed; third, common network analysis approaches, which can provide a theoretical basis to explore the optimal relationship between network structure and function, are summarized; finally, this paper presents the configuration and convergence characteristics of different types of wetland networks at multiple spatial scales. At the conclusion, suggestions for further work are presented. [ABSTRACT FROM AUTHOR]

Abstract: Different types of wetlands are hydraulically interconnected and form specific network structures that display systematic characteristics. The sustainable use of wetlands and water resources requires management approaches that incorporate Wetlands are not isolated spaces but complex habitats, in which many biotic and abiotic connections all around. The sustainable use of wetlands and water resources requires management approaches that incorporate explicitly the spatial and temporal interconnections among different hydrological units around a wetland. However, lateral, vertical and longitudinal hydrological connections have been destroyed heavily due to the impacts of anthropogenic activities. Wetlands tend to be managed in fragmented worldview behind non-sustainable growth. To highlight the importance of maintenance the integrity of interconnected wetlands, we developed a framework to use ecological network analysis in holistic assessment on the Okefenokee wetland system (WS) in USA. Two methods, ascendency analysis and network environ analysis, in ecological network method were used to explore the systematic attributes and components’ independencies of the wetland system. Results indicate the hydrological connections are extremely important for maintaining a wetland system. It is concluded that the proposed methods can provide effective ways to examine the hydrologic organization and components’ interdependencies in a wetland system and contributes to the basin-wide wetlands protection and water resources management. [Copyright &y& Elsevier]

Water browning or brownification refers to increasing water color, often related to increasing dissolved organic matter (DOM) and carbon (DOC) content in freshwaters. Browning has been recognized as a significant physicochemical phenomenon altering boreal lakes, but our understanding of its ecological consequences in different freshwater habitats and regions is limited. Here, we review the consequences of browning on different freshwater habitats, food webs and aquatic-terrestrial habitat coupling. We examine global trends of browning and DOM/DOC, and the use of remote sensing as a tool to investigate browning from local to global scales. Studies have focused on lakes and rivers while seldom addressing effects at the catchment scale. Other freshwater habitats such as small and temporary waterbodies have been overlooked, making the study of the entire network of the catchment incomplete. While past research investigated the response of primary producers, aquatic invertebrates and fishes, the effects of browning on macrophytes, invasive species, and food webs have been understudied. Research has focused on freshwater habitats without considering the fluxes between aquatic and terrestrial habitats. We highlight the importance of understanding how the changes in one habitat may cascade to another. Browning is a broader phenomenon than the heretofore concentration on the boreal region. Overall, we propose that future studies improve the ecological understanding of browning through the following research actions: 1) increasing our knowledge of ecological processes of browning in other wetland types than lakes and rivers, 2) assessing the impact of browning on aquatic food webs at multiple scales, 3) examining the effects of browning on aquatic-terrestrial habitat coupling, 4) expanding our knowledge of browning from the local to global scale, and 5) using remote sensing to examine browning and its ecological consequences., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)