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Salt marshes provide valuable ecosystem services including coastal protection by reducing wave loading on dikes and seawalls. If the topsoil is erosion resistant to fast-flowing water, it may also reduce breach depth if a dike fails. In this experiment, we quantified the topsoil erosion resistance from marshes and bare tidal flats with different soil types to understand the extent to which they can help reduce breach depth. Intact soil samples were collected from 11 locations in the Netherlands at different tidal elevations and then exposed for 3 h to 2.3 m/s currents. To the samples that remained stable after flow exposure, an artificial crack was made to test their stability following soil disturbance. All samples from the tidal flats were completely eroded, regardless of sediment type. In contrast, all samples from well-established marsh plateaus were stable as long as no disturbances were made, including those with sandy subsoils. After creating artificial cracks, samples with a thin cohesive top layer on top of sandy subsoil collapsed, while marshes with silty subsoils remained stable. Pioneer marshes on sandy substrate without a cohesive top layer were the only vegetated soils that completely eroded. The lower erosion of marshes with either sandy or silty soils compared to bare tidal flats was best explained by the presence of a top layer with belowground biomass, high organic content, high water content, and low bulk density. When analyzing the erodibility of marshes only, fine root density was the best predictor of erosion resistance. This study demonstrates the importance of preserving, restoring, or creating salt marshes, to obtain a topsoil that is erosion resistant under fast-flowing water, which helps reduce breach dimensions if a dike fails. The probability of topsoil erosion in established marshes with sandy subsoil is higher than in silty marshes. A silty layer of cohesive sediment on top of the sand provides extra erosion resistance as long as it does not break. Pioneer marshes that have not developed a cohesive top layer are erosion sensitive, especially in sandy soils. For future marsh creations, using fine-grained sediments or a mixture of sand with silt or clay is recommended.
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Solo , Áreas Alagadas , Ecossistema , Areia , Solo/química , ÁguaRESUMO
Despite its successes, the U.S. Endangered Species Act (ESA) has proven challenging to implement due to funding limitations, workload backlog, and other problems. As threats to species survival intensify and as more species come under threat, the need for the ESA and similar conservation laws and policies in other countries to function efficiently has grown. Attempts by the U.S. Fish and Wildlife Service (USFWS) to streamline ESA decisions include multispecies recovery plans and habitat conservation plans. We address species status assessment (SSA), a USFWS process to inform ESA decisions from listing to recovery, within the context of multispecies and ecosystem planning. Although existing SSAs have a single-species focus, ecosystem-based research can efficiently inform multiple SSAs within a region and provide a foundation for transition to multispecies SSAs in the future. We considered at-risk grassland species and ecosystems within the southeastern United States, where a disproportionate number of rare and endemic species are associated with grasslands. To initiate our ecosystem-based approach, we used a combined literature-based and structured World Café workshop format to identify science needs for SSAs. Discussions concentrated on 5 categories of threats to grassland species and ecosystems, consistent with recommendations to make shared threats a focus of planning under the ESA: (1) habitat loss, fragmentation, and disruption of functional connectivity; (2) climate change; (3) altered disturbance regimes; (4) invasive species; and (5) localized impacts. For each threat, workshop participants identified science and information needs, including database availability, research priorities, and modeling and mapping needs. Grouping species by habitat and shared threats can make the SSA process and other planning processes for conservation of at-risk species worldwide more efficient and useful. We found a combination of literature review and structured discussion effective for identifying the scientific information and analysis needed to support the development of multiple SSAs. Article impact statement: Species status assessments can be improved by an ecosystem-based approach that groups imperiled species by shared habitats and threats.
Mejoramiento de la Evaluación del Estado de una Especie bajo el Acta de Especies en Peligro de los Estados Unidos y Sus Consecuencias para los Retos de la Conservación Multiespecie a Nivel Mundial Resumen A pesar de su éxito, el Acta de Especies en Peligro de los E.U.A. (AEP) ha sido un reto de implementación por las limitaciones en su financiamiento, el retraso en la carga de trabajo y otros problemas. Conforme se intensifican las amenazas a la supervivencia de las especies y más especies resultan amenazadas, aumenta la necesidad de que la AEP y las políticas similares de otros países funcionen efectivamente. Los intentos por parte del Servicio Estadounidense de Pesca y Fauna (SEPF) para optimizar las decisiones de la AEP incluyen planes multiespecie de recuperación y planes de conservación de hábitat (PRH). Abordamos la evaluación del estado de las especies (EEE), un proceso del SEPF para orientar las decisiones del AEP desde el listado hasta la recuperación, dentro del contexto de la planeación multiespecie y de ecosistemas. Aunque las EEE existentes tienen un enfoque sobre una única especie, la investigación basada en el ecosistema puede orientar eficientemente a múltiples EEE dentro de una región y proporcionar una base para la transición a las EEE multiespecie en el futuro. Consideramos a las especies y los ecosistemas en riesgo de los pastizales del sureste de los Estados Unidos, en donde un número desproporcionado de especies raras y endémicas está asociado con los pastizales. Para iniciar nuestra estrategia basada en el ecosistema, usamos un formato de taller de World Café estructurado y basado en la literatura para identificar la necesidad de tener EEE. Las discusiones se centraron en cinco categorías de amenazas para las especies y ecosistemas de los pastizales, consistentes con las recomendaciones para volver a las amenazas compartidas un foco de la planeación bajo la AEP: (1) pérdida del hábitat, fragmentación y disrupción de la conectividad funcional; (2) cambio climático; (3) regímenes alterados de perturbación; (4) especies invasoras; y (5) impactos localizados. Para cada amenaza, los participantes del taller identificaron las necesidades científicas y de información, incluyendo la disponibilidad de bases de datos, prioridades de la investigación y necesidades de modelado y mapeado. La agrupación de las especies por hábitat y amenaza compartida puede hacer más eficientes y útiles el proceso de EEE y otros procesos de planeación de la conservación de especies en riesgo a nivel mundial. Encontramos una combinación de revisiones bibliográficas y discusiones estructuradas para identificar la información y el análisis necesarios para respaldar el desarrollo de múltiples EEE.
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Ecossistema , Espécies em Perigo de Extinção , Animais , Mudança Climática , Conservação dos Recursos Naturais , Humanos , Espécies IntroduzidasRESUMO
Eco-compensation (EC) for farmland conservation being implemented in China is a type of payments for ecosystem services (PES) scheme that seeks to balance ecosystem services (ESs) consumption and supply. Despite the growing body of literature on the integration of the demand for, and supply of ESs or the identification of mismatches between them, still many challenges remain to structurally integrate them in policy making facing fund-saving. Therefore, integrating ESs demand and supply at the micro-scale to provide novel insights into using compensation funds efficiently and optimizing the design of PES schemes deserves increasing attention. This study investigated an approach for integrating the demand for, and supply of farmland ESs, i.e., the public's preferences and farmers' pro-environmental behaviors related to farmland ESs, into the design of differentiated EC policies to obtain more ESs with lower input of EC funds. It proposed a theoretical framework and research approach to identify the pro-environmental farming behaviors that should be funded as priorities by matching micro farmland ES demand and supply in multiple scenarios. Then, using survey data collected from four cities in Hubei Province, China, and expert consultation data, empirical research was conducted. By matching the 'key ESs' on the demand side and 'specific ESs' on the supply side in scenarios I, II and III, eight most critical pro-environmental farming behaviors that should be funded as priorities for each scenario were identified. We maintain that the efficient and targeted use of EC funds can be better determined by matching ESs demand and supply from a micro-perspective since this approach provides insight and a framework to identify priorities for action. This approach could be extended to the conservation of different types of ecosystems as well as the design of corresponding PES schemes.
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Conservação dos Recursos Naturais , Ecossistema , Agricultura , China , Cidades , FazendasRESUMO
Understanding the trade-off between the loss of ecological lands and farmland to urbanisation could alleviate negative consequences to the environment and food security. This study aims to analyse the impact of urbanisation on ecological lands and farmland by comparing respective losses of habitat quality and agricultural productivity potential. Different scenarios are established indicating the priority of conserving ecological lands or farmland based on their vulnerability as measured by weight. With a land-use simulation model LANDSCAPE, the demand for urban land is met by occupying inferior ecological lands or farmland. Land-use patterns in each scenario are projected to 2035 in Wuhan (a rapidly urbanising city in China). As the weight of habitat quality decreases, the loss of habitat quality increases from 2.56 to 5.80%, while the loss of agricultural productivity potential decreases from 4.16 to 2.94%. The higher vulnerability of habitat quality loss indicates that ecological lands need a priori conservation than farmland in exchange for urbanisation.
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Conservação dos Recursos Naturais , Ecossistema , China , Cidades , FazendasRESUMO
Seagrasses are highly productive, but human nearshore activities have reduced their global distribution by >29% since the twentieth century. In the United States and Canada, the native seagrass Zostera marina (eelgrass) provides habitat for many species and multiple ecosystem services. By supplying spawning surface for fish and substrate for invertebrates, eelgrass creates foraging areas for high densities of migratory birds. Eelgrass beds stabilize sediment, protect adjacent shorelines, improve water quality, and sequester carbon in their underlying substrate. San Francisco Bay (California, USA) is a significant estuary for eelgrass, and recent surveys show that eelgrass beds are in decline. Protecting eelgrass is a conservation priority for federal, state, and local agencies, yet few studies have documented the extent of eelgrass loss due to human impacts such as boat anchoring. The purpose of our study was to provide factual evidence for policy makers by quantifying damage to eelgrass caused by illegal anchor-outs in San Francisco Bay, an issue that has been disputed for decades. Using aerial imagery and GIS analyses, we determined the amount of direct damage to eelgrass caused by anchor-outs. We found that boats damage up to 41% of the eelgrass bed, and each boat may cause up to 0.3 ha of damage. These results can be used to inform decisions about anchor-outs by stakeholders and government agencies. Furthermore, our efficient analytical approach could be implemented in other coastal regions.
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Zosteraceae , Animais , Baías , Canadá , Ecossistema , São Francisco , NaviosRESUMO
The great diversity of the invertebrate community thriving in the deepest sections of the gypsum karst system of the Monte Conca sinkhole (Sicily, Italy) suggests the existence of a complex food web associated with a sulfidic pool and chemoautotrophic microbial activity. To shed light on the peculiarity of this biological assemblage, we investigated the species composition of the invertebrate community and surveyed trophic interactions by stable isotope analysis. The faunal investigation conducted by visual censuses and hand sampling methods led to the discovery of a structured biological assemblage composed of both subterranean specialized and non-specialized species, encompassing all trophic levels. The community was remarkably diverse in the sulfidic habitat and differed from other non-sulfidic habitats within the cave in terms of stable isotope ratios. This pattern suggests the presence of a significant chemoautotrophic support by the microbial communities to the local food web, especially during the dry season when the organic input from the surface is minimal. However, when large volumes of water enter the cave due to local agricultural activities (i.e., irrigation) or extreme precipitation events, the sulfidic habitat of the cave is flooded, inhibiting the local autotrophic production and threatening the conservation of the entire ecosystem.
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Ecossistema , Microbiota , Animais , Sulfato de Cálcio , Invertebrados , Sicília , SulfetosRESUMO
Along with the increasing prominence of environmental risks such as soil surface source pollution and declining quality grade of arable land, the issues of how to address irrational fertilizer application and enhance the safety of agricultural products have attracted widespread attention. In this context, clarifying the main factors affecting farmers' use of soil testing and formulated fertilization technology (STFFT) can further improve the technology adoption rate and fertilizer utilization efficiency, promote standardized agricultural production and maintain the health and stability of soil ecology in black soil areas. This is of great significance to the construction of green agriculture, national dietary health and national food security. This study builds an "external environmental stimuli-perceived characteristics-adoption behavior" theoretical framework to investigate the decision-making and the dynamic influence mechanisms of farmers' adoption behavior of STFFT. Based on farmer survey data, the logistic-ISM model has been applied. The main findings are as follows. First, five types of influencing factors, namely individual characteristics, family characteristics, business characteristics, cognitive characteristics and external environmental characteristics, had significant "push" effects on farmers' STFFT adoption behavior. Among them, planting scale and technical training are the key factors influencing farmers' adoption of scientific fertilizer application technology. Second, both farmers' perceived ease of use and perceived usefulness play a significant role in farmers' decision-making process, and the easier farmers perceive STFFT to be to master and the greater the benefits it brings, the more pronounced the tendency to adopt the technology, all other influencing conditions being equal. Third, the main influencing factors of farmers' STFFT adoption behavior are intrinsically related and divided into four categories based on the magnitude of influence: deep-rooted, medium indirect, shallow indirect and superficial direct. In order to reduce further degradation of black soil caused by farmers' irrational production habits and to improve resource utilization efficiency, this study recommends the government to further regulate the land transfer market, strengthen the propagation of soil-conservation-type technologies in black soil areas, expand the breadth of agricultural technology training and enhance farmers' understanding and trust in STFFT. Thus, the maintenance of soil ecosystem in black soil areas, effective guarantee of food security and sustainable development of agriculture can be achieved.
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Ecossistema , Solo , Humanos , Fazendeiros/psicologia , Agricultura , Tecnologia , Fertilizantes , ChinaRESUMO
Rapid economic development and urbanization necessitate an understanding of anthropogenic effects on coastal eutrophication. It is a significant challenge for governments to alleviate water degradation and remediate coastal ecosystems. Shenzhen Bay in China, located in a developed and populous area, was selected to analyze the decadal scale influence of anthropogenic activities on eutrophication as well as the effectiveness of governmental remediation strategies. The results showed that the contribution of nutrients from anthropogenic sources accounted for over 80% of the total loads into the bay. Beginning in 1990, increased anthropogenic activities resulted in the loss of environmental capability and resilience, exacerbated eutrophication and water quality degradation. However, the status of eutrophication has been improved since 2005, following the application of intensive management actions implemented in 2000. The practice of eutrophication control suggested that, in view of technical and engineering feasibility, coastal strategies for similar shallow bays should initially reduce phosphorus, followed by nitrogen and eco-remediation to alleviate the serious aquatic situation immediately. The recovery period of eutrophication would be at least five years after governmental actions from Shenzhen Bay's experience. Furthermore, simulated scenarios indicated that eutrophication ranking of Shenzhen Bay could reach and remains medium Moderate, following a 35% reduction in total nitrogen and a 20% reduction in total phosphorus with corresponding eco-remediation.
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BACKGROUND AND OBJECTIVES: Duckweeds are the world's smallest flowering plants. Its existence is affected by the water quality and availability. The increased water demand and water scarcity in most of the Mediterranean countries as Jordan have caused remarkable lowering in the water-table which reduced floods and disappearance of the seasonal lakes. Due to this, aquatic plants that grow on good quality of fresh water have disappeared totally. Therefore, this paper highlights the native growth and conservation of duckweed (Lemnaceae) in Jordan. It also focuses on the identification of water sources for duckweed's movement. MATERIALS AND METHODS: Field surveys were conducted to identify water source for water bodies that contain duckweeds. These surveys included visits to the Zarqa river, dams, irrigation ponds and Jordan valley. The source of water for duckweed movement and availability was determined. Water samples from the targeted areas were analyzed for selected parameters as pH, EC, NO3, PO4, BOD5, Zn, Pb, Cd and Cu. RESULTS: The results showed that King Abdullah Canal and Zarqa river are the water sources that encourage the duckweeds growth. In Sukhnah, Jerash and Jordan valley areas, water analysis ranges (mg L-1) are: NO3 0.7-38, PO4 0.3-7.6 and BOD5 0-20. The pH range value is 7.1-8.1 and EC range value is 1.62-2.5 mS cm-1.The heavy metals values are, Zn is <0.02 mg L-1, Pb is <0.01 mg L-1, Cd is <0.002 mg L-1 and Cu is <0.01 mg L-1. CONCLUSION: It can be concluded that mitigation measures are highly needed to overcome and altering the quality of the natural water flowing and participation of governmental institutions is also required for the success of applying mitigation measures to preserve the aquatic plants.
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Araceae/crescimento & desenvolvimento , Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Jordânia , Poluentes Químicos da Água/análiseRESUMO
Salt marshes support estuarine biodiversity and provide ecosystem services; however, their general decay is being observed worldwide, in large part due to land reclamation. Accordingly, there is a growing concern about salt marsh preservation status having in mind the promotion of effective management decisions towards their conservation and restoration. Satellite imagery offers the opportunity to monitor land surface dynamics, constituting a fundamental information source for wetland monitoring. This study analyses spatial and temporal vegetation changes within Ria de Aveiro coastal lagoon between 1984 and 2017, by processing and analyzing TM and ETM+ Landsat imagery. A database consisting of 264 cloud-free images was collected and analyzed. The Normalized Difference Water Index was computed using the remote surface reflectance and was then used to distinguish land from water and to estimate the flooded lagoon area. Moreover, the tidal state was determined for each image from a tidal elevation record monitored at the lagoon entrance. Subsequently, four vegetation indices (VI) were computed and their spatial variability in the lagoon area uncovered by water was assessed. Spatially averaged spectral indices were also statistically analyzed and seasonal variations and interannual trends evaluated. Results show that the intertidal area increased, and VI values decreased indicating a possible reduction in the Chlorophyll content and suggesting that the new intertidal regions are mostly covered by mud. The spatially averaged VI values show seasonal patterns, with peaks in spring and summer, coinciding with high biomass productivity periods. The largest flooded area and VI modifications occurred after 1999, suggesting that changes are associated with dredging activities performed in the main lagoon channels. This study reinforced the potential of Landsat archives to monitor coastal wetlands, highlighting their importance for coastal managers of threatened systems, and therefore helping to define management strategies about the ecological conservation of estuarine systems.
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Biota , Monitoramento Ambiental , Fenômenos Fisiológicos Vegetais , Imagens de Satélites , Áreas Alagadas , Estuários , Dinâmica Populacional , Portugal , Estações do AnoRESUMO
AIM: The influence of humans on large carnivores, including wolves, is a worldwide conservation concern. In addition, human-caused changes in carnivore density and distribution might have impacts on prey and, indirectly, on vegetation. We therefore tested wolf responses to infrastructure related to natural resource development (i.e., human footprint). LOCATION: Our study provides one of the most extensive assessments of how predators like wolves select habitat in response to various degrees of footprint across boreal ecosystems encompassing over a million square kilometers of Canada. METHODS: We deployed GPS-collars on 172 wolves, monitored movements and used a generalized functional response (GFR) model of resource selection. A functional response in habitat selection occurs when selection varies as a function of the availability of that habitat. GFRs can clarify how human-induced habitat changes are influencing wildlife across large, diverse landscapes. RESULTS: Wolves displayed a functional response to footprint. Wolves were more likely to select forest harvest cutblocks in regions with higher cutblock density (i.e., a positive functional response to high-quality habitats for ungulate prey) and to select for higher road density in regions where road density was high (i.e., a positive functional response to human-created travel routes). Wolves were more likely to use cutblocks in habitats with low road densities, and more likely to use roads in habitats with low cutblock densities, except in winter when wolves were more likely to use roads regardless of cutblock density. MAIN CONCLUSIONS: These interactions suggest that wolves trade-off among human-impacted habitats, and adaptively switch from using roads to facilitate movement (while also risking encounters with humans), to using cutblocks that may have higher ungulate densities. We recommend that conservation managers consider the contextual and interacting effects of footprints when assessing impacts on carnivores. These effects likely have indirect impacts on ecosystems too, including on prey species.
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Most Latin American demands for drinking water are in or near urban areas. However, population growth and untreated sewage disposal degrade water quality, with negative effects for biodiversity and ecosystem services. Mobilizing society to monitor quality of urban watercourses facilitates training and allows diagnosis that may further help implement mitigation and management strategies. Therefore, our research was conducted in a > 4000 km2 metropolitan region of high human influence. Urban water body assessments were conducted by 1965 teachers and students and their consistency validated by rigorous scientific methods. The assessments revealed degradation of physical habitat, water quality, or biology in 91% of the evaluated urban stream sites. Increased knowledge concerning environmental stressors and biological responses by local citizens may increase their participation in public policy development and implementation. We conclude that participatory scientific monitoring is a viable way for improving science education, increasing social participation, and improving the ecosystem services provided by urban watercourses.
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Ecossistema , Rios , Ecologia , Monitoramento Ambiental , Humanos , EstudantesRESUMO
Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.
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Ecologia , Inundações , Sedimentos Geológicos , Camada de Gelo , Rios , Animais , Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Geografia , Fenômenos Geológicos , HumanosRESUMO
The newly developed IUCN Red List of Ecosystems is part of a growing toolbox for assessing risks to biodiversity, which addresses ecosystems and their functioning. The Red List of Ecosystems standard allows systematic assessment of all freshwater, marine, terrestrial and subterranean ecosystem types in terms of their global risk of collapse. In addition, the Red List of Ecosystems categories and criteria provide a technical base for assessments of ecosystem status at the regional, national, or subnational level. While the Red List of Ecosystems criteria were designed to be widely applicable by scientists and practitioners, guidelines are needed to ensure they are implemented in a standardized manner to reduce epistemic uncertainties and allow robust comparisons among ecosystems and over time. We review the intended application of the Red List of Ecosystems assessment process, summarize 'best-practice' methods for ecosystem assessments and outline approaches to ensure operational rigour of assessments. The Red List of Ecosystems will inform priority setting for ecosystem types worldwide, and strengthen capacity to report on progress towards the Aichi Targets of the Convention on Biological Diversity. When integrated with other IUCN knowledge products, such as the World Database of Protected Areas/Protected Planet, Key Biodiversity Areas and the IUCN Red List of Threatened Species, the Red List of Ecosystems will contribute to providing the most complete global measure of the status of biodiversity yet achieved.