Responses of Bacterial Taxonomical Diversity Indicators to Pollutant Loadings in Experimental Wetland Microcosms

Urbanization results in higher stormwater loadings of pollutants such as metals and nutrients into surface waters. This directly impacts organisms in aquatic ecosystems, including microbes. Sediment microbes are known for pollution reduction in the face of contamination, making bacterial communities an important area for bioindicator research. This study explores the pattern of bacterial responses to metal and nutrient pollution loading and seeks to evaluate whether bacterial indicators can be effective as a biomonitoring risk assessment tool for wetland ecosystems. Microcosms were built containing sediments collected from wetlands in the urbanizing Pike River watershed in southeastern Wisconsin, USA, with metals and nutrients added at 7 day intervals. Bacterial DNA was extracted from the microcosm sediments, and taxonomical profiles of bacterial communities were identified up to the genera level by sequencing 16S bacterial rRNA gene (V3–V4 region). Reduction of metals (example: 90% for Pb) and nutrients (example: 98% for NO3−) added in water were observed. The study found correlations between diversity indices of genera with metal and nutrient pollution as well as identified specific genera (including Fusibacter, Aeromonas, Arthrobacter, Bacillus, Bdellovibrio, and Chlorobium) as predictive bioindicators for ecological risk assessment for metal pollution.

Modeling the Climate Suitability of Northernmost Mangroves in China under Climate Change Scenarios

Mangroves are important wetland ecosystems on tropical and subtropical coasts. There is an urgent need to better understand how the spatial distribution of mangroves varies with climate change factors. Species distribution models can be used to reveal the spatial change of mangroves; however, global models typically have a horizontal resolution of hundreds of kilometers and more than 1 km, even after downscaling. In the present study, a maximum entropy model was used to predict suitable areas for the northernmost mangroves in China in the 2050s. An approach was proposed to improve the resolution and credibility of suitability predictions by incorporating land-use potential. Predictions were made based on two CMIP6 scenarios (i.e., SSP1-2.6 and SSP5-8.5). The results show that the northern edge of the natural mangrove distribution in China would migrate from 27.20° N to 27.39° N–28.15° N, and the total extent of suitable mangrove habitats would expand. By integrating 30 m resolution land-use data to refine the model’s predictions, under the SSP1-2.6 scenario, the suitable habitats of mangroves are predicted to be 13,435 ha, which would increase by 33.9% compared with the current scenario. Under the SSP5-8.5 scenario, the suitable area would be 23,120 ha, with an increased rate of 96.5%. Approximately 40–44% of the simulated mangrove patches would be adjacent to aquacultural ponds, cultivated, and artificial land, which may restrict mangrove expansion. Collectively, our results showed how climate change and land use could influence mangrove distributions, providing a scientific basis for adaptive mangrove habitat management despite climate change.

An Overview of the Determination of Biodiversity of Wetlands

Wetland ecosystems support rich and unique biodiversity. Biodiversity of a given ecosystem in general and wetlands in particular provide important insights to the ecological health of an area. The Ramsar Convention 1971 identified nine criteria for identifying wetlands of international importance. Out of the nine criteria, eight are linked to biodiversity of which three are based on sites of international importance for conserving biological diversity, two are specific for water birds, two are specific for fish, and one criterion for other taxa. Hence, determination of biodiversity of wetlands is of utmost importance. In order to understand that birds, fishes, amphibians, odonates, mammals, and aquatic plants were particularly selected as indicators of wetland biodiversity, the chapter discusses the different methodologies about determination of each of these taxa under different criteria as mentioned above. These methodologies will help various stakeholders in appropriate determination of biodiversity of wetlands of a particular area.

Wetland Ecosystems and Their Relevance to the Environment

As compared to the tropical evergreen forest, wetlands are also one of the most productive ecosystems in the biosphere and make a major contribution to the ecological sustainability of a region. The wetlands maintain biologically diverse communities having both ecological and economic value. Based on the immense environmental and sustainability benefits, wetlands have been demarcated as essential for the future of human existence. The future challenges pertaining to food, clean water and energy security, well-being of humans, natural disaster risk reduction, and climate change resilience can be met by preserving the wetlands. The chapter has an aim to provide insight on the fundamentals like the classifications, major functions, as well as the various factors affecting the wetland ecosystem. Other important aspects like the major threats leading to the loss of the wetlands, consequences of the loss or degradation of wetlands, and ways to preserve the wetlands are discussed.

Public Participation in Restoration and Sustainable Use of Wetland Ecosystem Services in India

Ecosystem services include conditions and processes that make up natural ecosystems and the species present therein. According to recent studies, wetland ecosystems provide the maximum service value per area by playing a significant role in regulating and purifying water supplies, controlling flood, acting as carbon-sinks, and sustaining human lives and livelihoods. Challenges like wetland loss and degradation, declining freshwater resources, and probable consequences of climate change have attracted significant scientific and public attention towards wetland conservation and restoration. Despite diligent conservation efforts, the global status of wetland security is still alarming. Long-term sustainable management and use of wetlands necessitate active public participation from all sectors. This study reviews the current status of different wetlands in India. It also provides a detailed discussion of different aspects of economic evaluation of ecosystem services, wetland restoration, and public participation for improving wetland policies and governance.

Humus substances in the swamp ecosystems of taiga zone of Western Siberia

Eutrophic peatlands with a predominantly humate type of humus is dominated according to content of hydrophobic humus substances accumulated in the solid phase of peat. Oligotrophic peatlands with fulvate type of humus are characterized by minimal storages. Mesotrophic peatlands occupy a transitional position, both in terms of storage and in terms of the humus type – humate-fulvate. Hydrophilic components of the water phase are characterized by fulvate humus, regardless of the type of peatland, but differ in the proportion of the contribution of humus substances in the amphiphilic system of swamp ecosystems. It is the highest in the thickness of the oligotrophic peatland almost 31%, slightly lower in the mesotrophic – 25% and much less in the eutrophic – 6%. Structural features of macromolecules of humic acids of swamp waters of various genesis are determined. The humic acids of mesotrophic waters are adjacent to the group of reduced compounds, they are more enriched with aromatic structures and carboxyl groups in relation to oligotrophic waters. The humic acids of oligotrophic waters belong to a group of oxygenated compounds, have low enrichment of nitrogen, contain more methoxyl carbon and carbohydrates (polysaccharides). These structural features are caused by geochemistry of waters feeding the peatlands and specific mechanisms of humic acids synthesis on the swamps of different genesis. The volume of dissolved organic carbon stock from wetland ecosystems through system of taiga rivers of left bank of Middle Ob is 805 kt per year.

A Literature Review of Wetland Treatment Systems Used to Treat Runoff Mixtures Containing Antibiotics and Pesticides from Urban and Agricultural Landscapes

Wetland treatment systems are used extensively across the world to mitigate surface runoff. While wetland treatment for nitrogen mitigation has been comprehensively reviewed, the implications of common-use pesticides and antibiotics on nitrogen reduction remain relatively unreviewed. Therefore, this review seeks to comprehensively assess the removal of commonly used pesticides and antibiotics and their implications for nitrogen removal in wetland treatment systems receiving non-point source runoff from urban and agricultural landscapes. A total of 181 primary studies were identified spanning 37 countries. Most of the reviewed publications studied pesticides (n = 153) entering wetlands systems, while antibiotics (n = 29) had fewer publications. Even fewer publications reviewed the impact of influent mixtures on nitrogen removal processes in wetlands (n = 16). Removal efficiencies for antibiotics (35–100%), pesticides (−619–100%), and nitrate-nitrogen (−113–100%) varied widely across the studies, with pesticides and antibiotics impacting microbial communities, the presence and type of vegetation, timing, and hydrology in wetland ecosystems. However, implications for the nitrogen cycle were dependent on the specific emerging contaminant present. A significant knowledge gap remains in how wetland treatment systems are used to treat non-point source mixtures that contain nutrients, pesticides, and antibiotics, resulting in an unknown regarding nitrogen removal efficiency as runoff contaminant mixtures evolve.

The Detection of Wetlands And Wetland Fragmentation Using Sentinel 1 And 2 Imagery: The Example of Southern Nigeria

Wetland ecosystems play key roles in global biogeochemical cycling, but their spatial extent and connectivity is often not well known. Here, we describe an approach suitable for application on a 1000 km scale using Sentinel-1 and Sentinel-2 imagery, exploiting the implementation of Random Forest algorithm in Google Earth Engine. The approach was used to detect the spatial coverage of wetland types focusing on the case of southern Nigeria, thought to be one of the most wetland-rich areas of Africa. We compiled 1050 wetland and non-wetland control points for algorithm training and validation, primarily from visual interpretation of high-resolution (<1 m pixel) imagery. This allowed us to establish the relative importance of 18 input channels derived from Sentinel-1 polarimetric and Sentinel-2 indices for classification of wetland. We estimate that the swamps, marshes, mangroves, and shallow water wetlands of southern Nigeria cover 29,900 km² with 2% uncertainty of 460 km². We found larger mangrove and smaller marsh extent than suggested by earlier, coarser spatial resolution studies. Average continuous wetland patch areas were 120 km², 11 km², 55 km² and 13 km² for mangrove, marsh, swamp, and shallow water respectively. Our final map with 10 m pixels also captures small patches of wetland, with 20% of wetland patches being <1 km2; these were clustered around urban centres, suggesting anthropogenic wetland fragmentation. Our approach can now be used across rest of Africa and globally to detect wetlands and wetland change which, in turn, will be crucial for improved land-surface climate models and wetland conservation.

Impact Analysis of Highway System on Wetland Vegetation in Northern China

Wetlands in northern China are complex ecosystems composed of grasslands, lakes, rivers and swamps, which have immense ecological values. When a highway system passes through a wetland, it has adverse effects on its ecosystem. However, in many cases, it is difficult to avoid a highway system pass through a wetland. Taking the Erka wetland in northern China as an example, nine survey lines, perpendicular to the highway, were set up. According to the distance from the highway, the plant multi-element information was collected. After the analysis of plant growth habits, spatial characteristics and profile features, the following four conclusions were drawn: (1) the highway system divided the plants habitat and made the vegetation communities on both sides develop anisotropically; (2) the highway system interfered with the interspecific competition of the nearby plant populations, making it easier for the plant communities with fast propagation speed, drought resistance and anti-interference to establish advantages; (3) the plant growth within 80 m of the highway was inhibited and (4) the wetland plant community succeeded to grassland plant community. In order to reduce the adverse impact of highway system on wetland ecosystems, it is suggested that in the follow-up highway upgrading project, either diversion of highway or construction of bridge or culvert excavation should be considered.