Browsing by Subject "Environmental Restoration and Remediation"

Now showing 1 - 4 of 4
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    An ecosystem-based deep-ocean strategy.
    (Science (New York, N.Y.), 2017-02) Danovaro, R; Aguzzi, J; Fanelli, E; Billett, D; Gjerde, K; Jamieson, A; Ramirez-Llodra, E; Smith, CR; Snelgrove, PVR; Thomsen, L; Dover, CL Van
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    Ecological restoration of rich fens in Europe and North America: from trial and error to an evidence-based approach.
    (Biol Rev Camb Philos Soc, 2015-02) Lamers, Leon PM; Vile, Melanie A; Grootjans, Ab P; Acreman, Mike C; van Diggelen, Rudy; Evans, Martin G; Richardson, Curtis J; Rochefort, Line; Kooijman, Annemieke M; Roelofs, Jan GM; Smolders, Alfons JP
    Fens represent a large array of ecosystem services, including the highest biodiversity found among wetlands, hydrological services, water purification and carbon sequestration. Land-use change and drainage has severely damaged or annihilated these services in many parts of North America and Europe; restoration plans are urgently needed at the landscape level. We review the major constraints on the restoration of rich fens and fen water bodies in agricultural areas in Europe and disturbed landscapes in North America: (i) habitat quality problems: drought, eutrophication, acidification, and toxicity, and (ii) recolonization problems: species pools, ecosystem fragmentation and connectivity, genetic variability, and invasive species; and here provide possible solutions. We discuss both positive and negative consequences of restoration measures, and their causes. The restoration of wetland ecosystem functioning and services has, for a long time, been based on a trial-and-error approach. By presenting research and practice on the restoration of rich fen ecosystems within agricultural areas, we demonstrate the importance of biogeochemical and ecological knowledge at different spatial scales for the management and restoration of biodiversity, water quality, carbon sequestration and other ecosystem services, especially in a changing climate. We define target processes that enable scientists, nature managers, water managers and policy makers to choose between different measures and to predict restoration prospects for different types of deteriorated fens and their starting conditions.
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    Hidden Loss of Wetlands in China.
    (Current biology : CB, 2019-09) Xu, Weihua; Fan, Xinyue; Ma, Jungai; Pimm, Stuart L; Kong, Lingqiao; Zeng, Yuan; Li, Xiaosong; Xiao, Yi; Zheng, Hua; Liu, Jianguo; Wu, Bingfang; An, Li; Zhang, Lu; Wang, Xiaoke; Ouyang, Zhiyun
    To counter their widespread loss, global aspirations are for no net loss of remaining wetlands [1]. We examine whether this goal alone is sufficient for managing China's wetlands, for they constitute 10% of the world's total. Analyzing wetland changes between 2000 and 2015 using 30-m-resolution satellite images, we show that China's wetlands expanded by 27,614 km2 but lost 26,066 km2-a net increase of 1,548 km2 (or 0.4%). This net change hides considerable complexities in the types of wetlands created and destroyed. The area of open water surface increased by 9,110 km2, but natural wetlands-henceforth "marshes"-decreased by 7,562 km2. Of the expanded wetlands, restoration policies contributed 24.5% and dam construction contributed 20.8%. Climate change accounted for 23.6% but is likely to involve a transient increase due to melting glaciers. Of the lost wetlands, agricultural and urban expansion contributed 47.7% and 13.8%, respectively. The increase in wetlands from conservation efforts (6,765 km2) did not offset human-caused wetland losses (16,032 km2). The wetland changes may harm wildlife. The wetland loss in east China threatens bird migration across eastern Asia [2]. Open water from dam construction flooded the original habitats of threatened terrestrial species and affected aquatic species by fragmenting wetland habitats [3]. Thus, the "no net loss" target measures total changes without considering changes in composition and the corresponding ecological functions. It may result in "paper offsets" and should be used carefully as a target for wetland conservation.
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    Potential impacts of leakage from deep CO2 geosequestration on overlying freshwater aquifers.
    (Environ Sci Technol, 2010-12-01) Little, Mark G; Jackson, Robert B
    Carbon Capture and Storage may use deep saline aquifers for CO(2) sequestration, but small CO(2) leakage could pose a risk to overlying fresh groundwater. We performed laboratory incubations of CO(2) infiltration under oxidizing conditions for >300 days on samples from four freshwater aquifers to 1) understand how CO(2) leakage affects freshwater quality; 2) develop selection criteria for deep sequestration sites based on inorganic metal contamination caused by CO(2) leaks to shallow aquifers; and 3) identify geochemical signatures for early detection criteria. After exposure to CO(2), water pH declines of 1-2 units were apparent in all aquifer samples. CO(2) caused concentrations of the alkali and alkaline earths and manganese, cobalt, nickel, and iron to increase by more than 2 orders of magnitude. Potentially dangerous uranium and barium increased throughout the entire experiment in some samples. Solid-phase metal mobility, carbonate buffering capacity, and redox state in the shallow overlying aquifers influence the impact of CO(2) leakage and should be considered when selecting deep geosequestration sites. Manganese, iron, calcium, and pH could be used as geochemical markers of a CO(2) leak, as their concentrations increase within 2 weeks of exposure to CO(2).