查看更多>>摘要：? 2021 The AuthorsThe increasingly active role of stakeholders in the development of innovative nature-based solutions calls for appropriate instruments to support and realise added value from their involvement. In this paper we apply a newly developed instrument “Cooperation for Added Value” (Co-Add) to a study area on the Dutch coast. The instrument draws on participatory game theory and policy analysis to provide a theoretically sound structure for facilitating interactions aimed at identifying shared opportunities and potential coalitions for cooperation. The application in the case study Noard-Fryslan B?tendyks affirmed that the Co-Add instrument systematically facilitated stakeholders in exploring potentially promising opportunities and gaining insight in the added value of engaging in diverse cooperations. Stakeholders came to understand which solutions were more achievable than others and what was needed to enable implementation in terms of collaboration, including the role of their own organization. Furthermore, social dilemmas in which a particular nature-based solution is attractive to a coalition of stakeholders but is not the most beneficial solution for a particular individual stakeholder, became clear. This represents a practical contribution to the range of participatory instruments that can be applied in societally challenging complex problems that require collaboration for their resolution.
查看更多>>摘要：? 2021 The AuthorsArtificial water-level fluctuations (WLF) seriously threaten the biodiversity and functioning of littoral zones in lake ecosystems. The use of artificial floating islands (AFI) to compensate for the deleterious effects of WLF on littoral habitats has been of increasing interest to environmental managers. Yet, the ecological efficiency of this solution is still very poorly documented. AFI are usually designed as simple vegetated floating mats. In this study, we designed an artificial Floating Littoral Zone (FLOLIZ), which mimics a natural littoral zone composed of a terrestrial section vegetated with helophytes and several underwater levels containing soil and hydrophytes. Next, we aimed to assess the effectiveness of FLOLIZ in supporting macroinvertebrate communities. Three FLOLIZs were installed in three bays of a French hydroelectric reservoir marked by high WLF. Taxonomic and functional metrics of macroinvertebrate communities in the three FLOLIZs were compared with control littoral stations over four seasons of one year. The cumulated abundance, taxonomic richness and diversity were significantly higher in the FLOLIZs than in the control littoral stations, particularly when water level rose abruptly (i.e., in spring) and during the post-drawdown season (i.e., in summer). Functional profiles of macroinvertebrate communities significantly differed between FLOLIZs and control littoral stations. More specifically, communities in littoral control stations were dominated by highly mobile and resistant taxa (e.g., Beetles, Bugs, Chironomids), while communities in the FLOLIZs were dominated by less mobile species with longer life cycles (e.g., Hydra sp., Oligochaeta). These findings show that FLOLIZs were more successfully colonized by original, diversified, and abundant macroinvertebrate communities with respect to littoral control stations. These preliminary results suggest that FLOLIZs could provide suitable, biogenic habitats for macroinvertebrates in reservoirs exhibiting high WLF. Longer term monitoring, including of other compartments than macroinvertebrates (e.g., fish), could provide additional evidence that FLOLIZs mitigate the deleterious effects of high WLF on aquatic biodiversity.
查看更多>>摘要：? 2021 Elsevier B.V.Ecological water replenishment is an effective method that can ensure the urban lake riparian plant restoration. Here, a coupled one-dimensional model was developed to simulate the plant restoration under the ecological water replenishment and the groundwater–vegetation interactions in the urban lake. Meanwhile, the habitat suitability rate was used to show the degree of the plant restoration. The simulation results revealed three characteristic zones of plant restoration along a cross-bank section under the combined effect of ecological water replenishment method and evapotranspiration: (1) an air-limiting zone at the lake bank where plant restoration was limited by air scarcity in the soil due to water replenishment; (2) a plant growth zone near the bank, which is the core zone of plant restoration that urban lake managers can consider; (3) a water-limiting zone far from the bank where the plant restoration was limited by water scarcity in the soil. Urban lake managers should give priority to control the initial water level in each cycle when ensuring the plant restoration. When the actual conditions were difficult to control the initial water level in each cycle, the replenishment cycle could be controlled to improve the plant restoration degree. These findings demonstrated that the interplays of ecological and hydrological processes in urban lake marshes, and provided a management model tool for urban lake managers facing riparian plant restoration problems.
查看更多>>摘要：? 2021 The AuthorsSalt marshes provide valued services to coastal communities including nutrient cycling, erosion control, habitat provision for crustaceans and fish (including juvenile and forage fish), and energy transfer from the detrital based food web to the greater estuarine system. Living shorelines are erosion control structures that recreate natural shorelines, such as fringing marshes, while providing other beneficial ecosystem services. Living shorelines are expected to provide fish and crustacean (nekton) habitat, but few comprehensive studies have evaluated nekton habitat use across a range of living shoreline settings and ages. We sampled the intertidal marsh and subtidal shallow water nekton community at 13 paired living shoreline and reference marsh sites, with living shorelines ranging in age from 2 to 16 years from construction. We compared nekton diversity, nekton community abundance, nekton community biomass, forage abundance, and juvenile abundance at reference marshes and living shorelines. Our results indicate that living shorelines are providing suitable marsh habitat for nekton communities, including juveniles and forage base species. The difference in living shoreline construction (rock sill, soil composition) did not appear to diminish habitat quality in the marsh or in nearshore waters, and rock sills may provide enhanced structural shoreline habitat. Living shorelines have the potential to combat marsh habitat loss and provide resilient nekton nursery habitat.
查看更多>>摘要：? 2021 Elsevier B.V.Ecosystem service changes associated with land use and land cover change (LULC) will provide an important indicator and an early warning of ecological changes. However, there have been few attempts to estimate the effects of LULC on ecosystem services in desert-oasis ecotones, which are recognized as critical ecological barriers and buffers that prevent deserts from expanding into oases. Here, we used Landsat image-based LULC maps (1988–2018) and a modified benefit transfer method to estimate the changes in ecosystem service value (ESV) in response to LULC in Dengkou County along the Yellow River, China. Our results showed that the most significant feature of LULC in Dengkou County was a large area expansion of cropland and a reduction in the area of desert. The total estimated ESV was nearly US $400 million year?1, of which 76% was derived from cropland, water bodies and rangelands. LULC resulted in a net increase in the total ESV by US$ 43.7 million during 1988–2018. Cropland expansion accounted for approximately 72% of the increase in the total ESV, thereby outweighing the huge decrease in ESV due to the expense of woodlands, rangelands and water bodies. Many low ESV clustering areas appeared in the central part of the county, resulting in ESV loss of approximately US $13.4 million, all of which was due to the conversion of water bodies to bare land and rangelands. Our results provide powerful evidence to make informed land use decisions for relevant managers and help fill the gap between the supply of ecosystem services and the societal demands for these services.
查看更多>>摘要：? 2021 Elsevier B.V.As wildfires increase in extent and severity, we need new tools to rehabilitate burned landscapes. We tested the effectiveness of adding fire moss tissue, produced in the greenhouse, as a bio-inoculant to severely burned soils in dry mixed conifer forests. We conducted three sequential experiments using knowledge gained from previous experiments to fine-tune fire moss delivery methods. The first two experiments began in July 2017, less than ten days after a wildfire in Arizona, United States. First, we added disaggregated (passed through a 2 mm sieve) cultivated moss tissue to burned soil surfaces, which was immediately collected by ants. In a second experiment, we added two preparations designed to reduce ant collection: moss rolled into pellets using diatomaceous earth and moss ground to a powder. Pelletization increased Bryum argenteum cover (F[3,55] = 12.32, p < 0.001) and the number of distinct moss colonies (F[3,55] = 11.87, p < 0.001) when compared to untreated control plots, although cover remained low (1%). A third experiment took place four months postfire in New Mexico. Sieved moss, pelletized moss, and pelletized moss at a high (5×) application rate were added to a burned forest. The high-rate pelletized treatment increased B. argenteum colony count by 140% compared to controls (F[3,44] = 2.37, p = 0.084), but did not increase cover (F[3,44] = 1.19, p = 0.325). At both sites, an extreme drought (Palmer Drought Severity Index < ?4) during the winter of 2017–18 likely reduced success. We recommend further refinement and testing of pelletization in non-drought conditions.
查看更多>>摘要：? 2021 Elsevier B.V.The urbanisation and hardening of shorelines is likely to continue in response to coastal population growth and climate change. To mitigate associated ecological impacts, ecological engineering is being increasingly applied to enhance local biodiversity. This includes retrofitting topographically complex tiles or units onto intertidal artificial structures to mimic features of the natural hard-bottom habitats that were lost. However, the effect of material (different rock types) on the biotic colonisation of these habitat enhancements has rarely been investigated. We constructed complex tiles using a range of materials (concrete, granite, limestone, pink sandstone, violet sandstone, and a composite of the natural stones) to test their effects on the colonisation and establishment of intertidal algae and macrofaunal communities on seawalls in Singapore. We found no significant differences in macrofaunal species richness, total abundance, and community composition among treatments. There were only minor differences in algal community composition, total algal cover, and algal succession patterns among tile types. For both macrofaunal and algal communities, site-specific differences significantly affected colonisation. Our study suggests that material does not substantially influence biotic colonisation on habitat enhancement units and, therefore, other factors such as the associated environmental impacts of potential fabrication materials could be weighted more heavily when planning ecological engineering solutions for hardened shorelines.
查看更多>>摘要：? 2021 Elsevier B.V.Saline contaminants from potash mining endanger aquatic ecosystems. Uncovered piles of potash tailings release high amounts of chloride and sodium. Conventional coverage systems with a transpiration-intensive vegetation on a soil layer reduce percolation water only to some extent and do not protect the surrounding environment sufficiently. Powerful sealings are used to cover other mining deposits but are still uncommon for potash tailings piles. Because clay for constructing a sealing is limited, an alternative coverage system is required. The aim of this study is to identify a coverage system that conserves resources but also effectively minimises the release of contaminants. Water balance components (evapotranspiration, runoff, storage) of 44 different coverage systems were modelled with BOWAHALD. 4 model settings describe common conventional coverage and 40 settings include an additional sealing. The chosen coverage systems differ in soil layer thickness (1.5 to 3 m), vegetation productivity as well as in the thickness (10 and 50 cm) and impermeability of the sealing (kf values range between 8 × 10?08 and 5 × 10?09 m/s). The most impermeable sealing is also common whereas the less impermeable sealings are new designed. The results show that an additional sealing always outperforms (max. 26% percolation rate) conventional coverage without an additional sealing (28.7% percolation rate). Furthermore, a coverage system with less impermeable sealing and lush vegetation can substitute a coverage system with a more impermeable sealing and sparse vegetation without changing the percolation rate. Site-specific examinations, considering geographical orientation and inclination, show that a more impermeable sealing works best on north-facing slopes, whereas lush vegetation performs better on south-facing slopes. A mixed coverage according to site-specific performance reduces the percolation rate more than uniform coverage and requires less sealing material. I conclude that a mixed and site-specific coverage system is the most effective one to improve water quality in post-mining landscapes.
查看更多>>摘要：? 2021 The AuthorsThe combination of ongoing climate change and the historical loss of streams and wetland areas have presented new ecological challenges. These challenges became evident during a massive fish kill in Lake Fil, Denmark, in August 2018. We know that high amounts of labile organic matter entered the lake after a particularly heavy rainfall that followed a long period of heat and drought. Bacteria decomposed the organic matter, resulting in a quickly deoxygenated lake and an extensive fish kill. However, we do not know whether there is spatial variation in the amount of transportable labile matter across the catchment area. Identifying catchment ‘hotspots’ that sustain particularly high oxygen consumption rates will help managers to pursue interventions that can promote a high ecological quality of Lake Fil and its catchment. The method we developed to identify hotspots can be used by practitioners everywhere to prepare for and mitigate events similar to the 2018 disaster at Lake Fil. To identify hotspots in the stream network that feeds into Lake Fil, we measured oxygen consumption rates and environmental variables at 13 sites on five occasions. We found that oxygen consumption rates varied 2–16-fold between sites and 2–13-fold between sampling days. Oxygen consumption rates were positively related to the concentration of tryptophan-like material and ammonium but negatively related to the complexity of humic substances. Together, these variables accounted for 65% of the variation in the oxygen consumption rate across sub-catchments. High levels of tryptophan-like material and dissolved nutrients derive from intensive agricultural land use in the catchment. However, all oxygen consumption rates measured in this paper were apparently lower than those during the fish kill of August 2018, when the catchment fed higher concentrations of labile organic matter into the lake. The risk of anoxic water and fish kills can be mitigated by reducing and dispersing the input of labile organic matter following shifting periods of drought and heavy rain, which can be done by creating wetlands in the stream network or by implementing biogas facilities, thereby reducing pulses of organic matter and nutrients entering the stream.
查看更多>>摘要：? 2021In 2020, fires in the Pantanal, the world's largest continuous tropical wetland, made global news. The flames destroyed almost one-third of the biome. Furthermore, 43% of the affected area was burnt for the first time in 20 or even more years. As the combination of extreme drought and anthropogenic actions that caused these extreme wildfires is still prevalent, scientifically informed actions are necessary to prevent catastrophic fires in the future. Fire prevention, as well as restoration need to be spatially prioritised, as it is unfeasible to plan actions for the whole extent (150,355 km2) of the Brazilian Pantanal. In this study, we identified areas of high fire risk based on meteorological fire risk tendency for 1980–2020, fire intensity, last year with fire, the recurrence of fires for 2003–2020, and remaining areas of natural forest vegetation around watercourses. These native remnants include unburnt areas that can serve as refuges for fire-sensitive species and are important for fire prevention. We identified 246 km2 with high fire risk, i.e., high probability of megafires, with vegetation types that support fire-sensitive plant species. We found that while 179 km2 had high or medium natural regeneration potential, 66 km2 had low potential and needed active restoration. Over 3120 km2 have been severely degraded by recent fires. About 93% of these areas have high or medium potential for natural regeneration, where the suggested actions are passive restoration and Integrated Fire Management. We estimated the cost of post-fire restoration for areas with high and medium potential for natural regeneration to be around 123 million USD. In areas with low regeneration potential (219 km2), we suggest active restoration. The cost to restore these areas using transplanted seedlings or enrichment planting is estimated between 28 and 151 million USD.
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