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1.
The evaluation of conservation effectiveness for wetland protected areas (WPAs) is essential to underpin knowledge-based conservation policies and funding decisions by government and managers. In this paper, the conservation effectiveness for 28 WPAs in Northeast China from 2000 to 2012 was quantitatively evaluated using landsat thematic mapper image data and a maximum entropy model (Maxent). The spatial distribution of conservation effectiveness and the influence of human activities on conservation effectiveness were determined by combining a landscape development intensity (LDI) index and spatial analysis in a geographical information system. The results showed that the natural wetland area of all WPAs in Northeast China declined by 11.5 % and the conservation effectiveness of most of these WPAs decreased between 2000 and 2012. A significant negative correlation between the LDI index and conservation effectiveness (r = ?0.824, p < 0.01) suggested that human activities were responsible for the low conservation effectiveness of WPAs. The WPAs with the high conservation effectiveness were mainly located in the Da-Xing’an and Xiao-Xing’an Mountains, where anthropogenic activities were limited. The reduction in the conservation effectiveness of WPAs in the Songnen and Sanjiang Plains, which showed the most degradation, was due to conversion of wetlands to croplands. This research offers an efficient and effective method to evaluate the conservation effectiveness of WPAs. The results of this study will inform future ecological conservation and management of WPAs in China.  相似文献   

2.
A study was conducted to determine if surveys of hydric soils could be used as a historic baseline to estimate wetland losses. Soils were digitized from county soil surveys and wetlands were digitized from National Wetlands Inventory (NWI) maps for two adjacent coastal counties in North Carolina. The two counties were located on the lower Atlantic Coastal Plain and have extensive areas of hydric soils, as much as 96% of the land surface area. Using hydric soils from soil surveys and wetlands from NWI maps, wetland losses since settlement were calculated to be 65% for Washington County and 38% for Tyrrell County. The NWI wetlands were compared to a mid-1950s wetlands survey to determine recent wetland losses. A large percentage of the wetland losses occurred between 1950 and 1980 for Washington County compard to Tyrrell County. Wetland losses for both counties occurred primarily on mineral hydric soils and the current wetlands distribution corresponded well with the distribution of organic soils.  相似文献   

3.

Wetland ecosystems perform a multitude of services valued by society and provide critical habitat for migratory birds and other wildlife. Despite their importance, wetlands have been lost to different local, regional, and global drivers. Remaining wetlands are extremely sensitive to changing temperature and precipitation regimes. Management of grassland areas in wetland catchments may be an effective strategy for counteracting potentially negative impacts of climate change on wetlands. Our objective was to estimate the effects of climate changes on wetland hydrology, and to explore strategies for increasing surface-water inputs to wetlands. We coupled a field study with process-based simulation modeling of wetland-water levels. We found that climate change could decrease the number of wetlands that hold ponded water during the waterfowl breeding season by 14% under a hot wet scenario or 29% under a hot dry scenario if no upland-management actions were taken. Upland burning reduced pond losses to 9% (hot wet) and 26% (hot dry). Upland grazing resulted in the smallest loss of ponded wetlands, 6% loss under the hot-and-wet scenario and 22% loss under the hot-and-dry scenario. Overall, water inputs could be increased by either burning or grazing of upland vegetation thereby reducing pond losses during the waterfowl breeding season. While field results suggest that both grazing and burning can reduce the vegetative structure that could lead to increases in runoff in grassland catchments, our model simulations indicated that additional actions may be needed for managers to minimize future meteorologically driven water losses.

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4.
The Great Artesian Basin is an aquifer system that underlies a large area of north-eastern Australia. The spring wetlands in the Great Artesian Basin are of conservation significance because they provide habitat for endemic species including fish, invertebrates and plants. Since European settlement massive quantities of water have been artificially extracted through bores, reducing spring-flows. Records of the springs of the Queensland section of the Great Artesian Basin (excluding Cape York Peninsula) were compiled from a range of historical sources. Most remaining active springs were visited and surveyed, the physical attributes of the springs described and their current status determined. Recharge springs occur in areas where the evidence suggests the basin is recharged by rainfall and 93% of the original 245 spring-groups in these areas are still active. Discharge springs occur in sections of the Basin down-gradient of the recharge areas and only 36% of the original 300 spring-groups in these areas have at least some springs that are still active. The capping of bores could provide a partial restoration of artesian pressure and enhance spring flows. Of the active spring-groups surveyed 26% have suffered major or total damage as a result of excavation of the wetlands. An emerging threat is the use of exotic grasses as ponded pastures, which have the ability to dominate the habitat of spring wetlands. The potential impacts of other threats including those associated with stock, exotic animals and fire are also discussed. Mitigating these threats requires a conservation strategy that seeks to protect remaining springs with high conservation values.  相似文献   

5.
陈红  欧小杨  吕英烁  李晓溪  郑曦 《生态学报》2024,44(12):5128-5139
气候变化通过改变湿地水文过程等影响湿地的空间分布,城市化进程加剧了湿地破碎化程度并导致湿地生境退化,构建连续的湿地生态保护网络体系有利于应对气候变化和城市发展带来的负面影响、提高生物多样性保护水平。北京市现有湿地空间分布呈现斑块面积小、破碎化程度高等特点,为优化湿地保护区格局并应对气候变化和城市发展对北京市湿地生物多样性的影响,基于系统保护规划方法,以Marxan作为空间优化模型,结合PLUS模型和MaxEnt模型,模拟预测北京市湿地优先保护格局、识别湿地保护空缺并构建湿地分级保护区格局。研究表明:2020年北京市湿地存在80.15km2的保护空缺、2035年和2050年优化后湿地保护区占比分别为87.54%和85.95%,在满足本研究预设的生物多样性保护目标的前提下符合北京市湿地保护规划对湿地保护率的要求。为最优化资源分配,综合时空变化对湿地保护区空间分布的影响,构建了湿地分级保护区格局,将湿地保护区分为湿地永久保护区、湿地一级临时保护区和湿地二级临时保护区三个等级,以期为北京市分期建设湿地保护区、优化湿地生态保护网络体系和保护湿地生物多样性提供依据。  相似文献   

6.
Grassland managers often regard woody vegetation as hostile habitat that potentially reduces the abundance and fecundity of wildlife that use grasslands. We tested that assumption for waterfowl by examining patterns of nest success on study areas that differed in current extent and previous management of woody vegetation. We located and monitored 1,064 waterfowl nests on 33 federally owned Waterfowl Production Areas (WPAs) in western Minnesota during 2008–2010. Sites contained 0.3–15.1% woodland and also varied markedly in extent of shrubs and scattered trees. Average nest success was low (12.9%), but ranged from 1.5% to 38.7% among site-years. Nests were more likely to succeed when located in landscapes containing more grass (500-m scale) and fewer wetlands (100-m scale), but none of 8 variables measuring woody vegetation were negatively associated with nest survival and 1 variable (abundance of lone trees) was positively associated with nest survival. Our results indicate that management efforts focusing on removing woody vegetation are unlikely to provide improvements in nest survival rates for breeding waterfowl, except to the extent that such management is necessary to maintain large tracts of grassland. © 2012 The Wildlife Society.  相似文献   

7.
Wetlands provide key functions in the landscape from improving water quality, to regulating flows, to providing wildlife habitat. Over half of the wetlands in the contiguous United States (CONUS) have been converted to agricultural and urban land uses. However, over the last several decades, research has shown the benefits of wetlands to hydrologic, chemical, biological processes, spurring the creation of government programs and private initiatives to restore wetlands. Initiatives tend to focus on individual wetland creation, yet the greatest benefits are achieved when strategic restoration planning occurs across a watershed or multiple watersheds. For watershed-level wetland restoration planning to occur, informative data layers on potential wetland areas are needed. We created an indicator of potential wetland areas (PWA), using nationally available datasets to identify characteristics that could support wetland ecosystems, including: poorly drained soils and low-relief landscape positions as indicated by a derived topographic data layer. We compared our PWA with the National Wetlands Inventory (NWI) from 11 states throughout the CONUS to evaluate their alignment. The state-level percentage of NWI-designated wetlands directly overlapping the PWA ranged from 39 to 95%. When we included NWI that was immediately adjacent to the overlapping NWI, our range of correspondence to NWI ranged from 60 to 99%. Wetland restoration is more likely on certain landscapes (e.g., agriculture) than others due to the lack of substantive infrastructure and the potential for the restoration of hydrology; therefore, we combined the National Land Cover Dataset (NLCD) with the PWA to identify potentially restorable wetlands on agricultural land (PRW-Ag). The PRW-Ag identified a total of over 46 million ha with the potential to support wetlands. The largest concentrations of PRW-Ag occurred in the glaciated corn belt of the upper Mississippi River from Ohio to the Dakotas and in the Mississippi Alluvial Valley. The PRW-Ag layer could assist land managers in identifying sites that may qualify for enrollment in conservation programs, where planners can coordinate restoration efforts, or where decision makers can target resources to optimize the services provided across a watershed or multiple watersheds.  相似文献   

8.
9.
Seasonal forest pools (SFPs) are geographically- and hydrologically-isolated ponded wetlands, in that they are topographically isolated from other surface waters. SFPs occur commonly throughout the temperate forests of the eastern United States and adjacent Canada. SFPs are ephemeral in occurrence, typically drying annually. The regular drying of SFPs excludes fish from these habitats, and as a result, they are the preferred breeding habitat of some amphibians, notably ambystomid (‘mole’) salamanders and wood frogs (Rana sylvatica Le Conte). The pools also support a rich and diverse invertebrate fauna. The duration of the wet phase, or hydroperiod of SFPs, has been repeatedly shown to be the dominant influence on the composition and fitness of the faunal community of the pools. Despite the importance of SFP hydrology, it is a poorly studied subject. This paper reviews the limited state-of-knowledge of seasonal forest pool hydrology and associated basin morphology. The review discusses findings from studies of other isolated ponded wetlands that could be applicable to our understanding of the hydrology of SFPs.  相似文献   

10.
ABSTRACT Staging areas and migratory stopovers of wetland birds can function as geographic bottlenecks; common dependence among migratory wetland bird species on these sites has major implications for wetland conservation. Although 90% of playa wetlands in the Rainwater Basin (RWB) region of Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for up to 10 million waterfowl each spring. Our objectives were to determine local (within wetland and immediate watershed) and landscape-scale factors influencing wetland bird abundance and species richness during spring migration at RWB playas. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 1.6 million individual migratory wetland birds representing 72 species during spring migrations 2002–2004. We tested a priori hypotheses about whether local and landscape variables influenced overall species richness and abundance of geese, dabbling ducks, diving ducks, and shorebirds. Wetland area had a positive influence on goose abundance in all years, whereas percent emergent vegetation and hunting pressure had negative influences. Models predicting dabbling duck abundance differed among years; however, individual wetland area and area of semipermanent wetlands within 10 km of the study wetland consistently had a positive influence on dabbling duck abundance. Percent emergent vegetation also was a positive predictor of dabbling duck abundance in all years, indicating that wetlands with intermediate (50%) vegetation coverage have the greatest dabbling duck abundance. Shorebird abundance was positively influenced by wetland area and number of wetlands within 10 km and negatively influenced by water depth. Wetland area, water depth, and area of wetlands within 10 km were all equally important in models predicting overall species richness. Total species richness was positively influenced by wetland area and negatively influenced by water depth and area of semipermanent wetlands within 10 km. Avian species richness also was greatest in wetlands with intermediate vegetation coverage. Restoring playa hydrology should promote intermediate percent cover of emergent vegetation, which will increase use by dabbling ducks and shorebirds, and decrease snow goose (Chen caerulescens) use of these wetlands. We observed a reduction in dabbling duck abundance on wetlands open to spring snow goose hunting and recommend further investigation of the effects of this conservation order on nontarget species. Our results indicate that wildlife managers at migration stopover areas should conserve wetlands in complexes to meet the continuing and future habitat requirements of migratory birds, especially dabbling ducks, during spring migration.  相似文献   

11.
The complexity of nature conservation raises questions about biodiversity protection at the level of species as well as their spatial distribution between differently designated nature conservation areas. We have concentrated on comparison of the existing protected areas and recently established conservation initiative areas—Important Plant Areas. We have estimated how well these areas support the protection of two plant groups—bryophytes and vascular plants. We sought answers to the following questions: (a) are there any trends in the distribution of protected bryophyte and vascular plant species in the protected areas network, and (b) does the Important Plant Areas network promote better protection of bryophyte species compared with the existing protected areas network. Our results demonstrated that bryophytes need special care in nature conservation decisions to reach the reasonable conservation target. Important Plant Areas that were targeted to vascular plants have less importance in preserving bryophyte diversity than already existing conservation areas system. Conservation programs like IBA, IPA etc. have their specific tool and outcome to add conservation values to the existing protected areas system.  相似文献   

12.
Measuring the success of wetland restoration efforts requires an assessment of the wetland plant community as it changes following restoration. But analyses of restored wetlands often include plant community data from only one time period. We studied the development of plant communities at 13 restored marshes in northern New York for 4 years, including 1 year prior to restoration and 3 years afterwards. Restored wetlands ranged in size from 0.23 to 1.70 ha. Four reference wetlands of similar basin morphology, soil type, and size (0.29–0.48 ha) that occurred naturally in the same area were studied as comparisons. Dike construction to restore hydrology disturbed the existing vegetation in some parts of the restored sites, and vegetation was monitored in both disturbed and undisturbed areas. Undisturbed areas within the restored sites, which were dominated by upland field grasses before restoration, developed wetland plant communities with lower wetland index values but comparable numbers of wetland plant species than the reference wetlands, and they lagged behind the reference sites in terms of total wetland plant cover. There were significantly more plant species valuable as food sources for wetland birds, and a significantly higher percent cover of these species, at the undisturbed areas of the restored sites than at the reference wetlands. Areas of the restored sites that were disturbed by dike construction, however, often developed dense, monospecific cattail stands. In general, the plant communities at restored sites became increasingly similar to those at the reference wetlands over time, but higher numbers of herbaceous plants developed at the restored sites, including food plants for waterfowl, rails, and songbirds. Differences in shrub cover will probably lessen as natural recolonization increases shrub cover at the restored sites. Natural recolonization appears to be an effective technique for restoring wetlands on abandoned agricultural fields with established plant cover, but it is less successful in areas where soil has been exposed by construction activity.  相似文献   

13.
Wetlands support unique biota and provide important ecosystem services. These services are highly threatened due to the rate of loss and relative rarity of wetlands in most landscapes, an issue that is exacerbated in highly modified urban environments. Despite this, critical ecological knowledge is currently lacking for many wetland‐dependent taxa, such as insectivorous bats, which can persist in urban areas if their habitats are managed appropriately. Here, we use a novel paired landscape approach to investigate the role of wetlands in urban bat conservation and examine local and landscape factors driving bat species richness and activity. We acoustically monitored bat activity at 58 urban wetlands and 35 nonwetland sites (ecologically similar sites without free‐standing water) in the greater Melbourne area, southeastern Australia. We analyzed bat species richness and activity patterns using generalized linear mixed‐effects models. We found that the presence of water in urban Melbourne was an important driver of bat species richness and activity at a landscape scale. Increasing distance to bushland and increasing levels of heavy metal pollution within the waterbody also negatively influenced bat richness and individual species activity. Areas with high levels of artificial night light had reduced bat species richness, and reduced activity for all species except those adapted to urban areas, such as the White‐striped free‐tailed bat (Austronomus australis). Increased surrounding tree cover and wetland size had a positive effect on bat species richness. Our findings indicate that wetlands form critical habitats for insectivorous bats in urban environments. Large, unlit, and unpolluted wetlands flanked by high tree cover in close proximity to bushland contribute most to the richness of the bat community. Our findings clarify the role of wetlands for insectivorous bats in urban areas and will also allow for the preservation, construction, and management of wetlands that maximize conservation outcomes for urban bats and possibly other wetland‐dependent and nocturnal fauna.  相似文献   

14.
Stream discharge and chemistry (total suspended solids TSS, nitrogen N, and phosphorus P) were monitored for 15 months in six agricultural watersheds on the U.S. Mid-Atlantic coastal plain. Watersheds with similar land uses and a range of hydric soils were used to test the hypothesis that hydric soils generate large storm discharges due to low permeability, resulting in watershed areas with high loss rates of N, P, and TSS. To test the hypothesis, discharge was monitored continuously, and a flow separation method quantified the base and stormflow contributions. Another primary goal was to measure base and stormflow chemistry to quantify N, P, and TSS export. Baseflow chemistry was monitored monthly, and 31 storm events were sampled. Baseflow chemistry varied little over the 15 months, but stormflow chemistry was dynamic, with three major patterns: (1) TSS and particulate N and P had large, brief peaks during the rising limb of storm hydrographs; (2) phosphate and ammonium had broader peaks close to maximum discharges; and (3) nitrate concentrations decreased during the rising limb, slowly returning to pre-storm levels. Event water yields were correlated with volume-weighted mean concentrations (VWMs) of N, P, and TSS, providing a basis for estimating VWMs of unsampled events. Export coefficients (kg ha?1 year?1) ranged over 22–33 for TN, 0.9–1.4 for TP, and 240–1140 for TSS. Most P and TSS export occurred during storms (71–99%), while most N export occurred during baseflow (52–84%). The discharge data did not support the hypothesis, and watershed slope, not hydric soils, was the major control on storm discharge. Surface ponding of water on hydric soils intercepted runoff, reducing the impacts of the low infiltration rates.  相似文献   

15.
Because of their biogeographical and geomorphological context, the northeastern Algeria wetlands present high species and community richness. The vegetation study of the Ramsar site of Beni-Belaid (Kabylia) showed the existence of four main communities, distributed along gradients of hydrology and disturbance. The obtained results reveal worrying threats on short term: overgrazing results in the lake invasion by the sand eroded from the coastal dune; agriculture induces illegal cutting, water pollution and excessive groundwater pumping; finally, hunting and fishing are illegally practiced into the Ramsar site. The awareness of public authorities is needed in order: (1) to completely protect the wetland with the aim of restoring a riparian forest belt; and (2) to initiate a campaign for increasing the local population awareness, and its involvement in conservation programs.  相似文献   

16.
许丁雪  吴芳  何立环  刘海江  江源 《生态学报》2019,39(20):7493-7501
生态系统服务与人类福祉密切相关,人类活动引起的土地利用变化是生态系统服务变化的主要驱动力之一。运用InVEST模型估算张家口-承德地区产水量和土壤保持量,并分析不同海拔和坡度条件下,2011—2015年土地利用以及产水和土壤保持服务的变化,研究结果表明:建设用地和乔木林地分别为面积增加量和减少量最多的用地类型,陡坡地段建设用地增加的同时水体减少;灌木林地是产水和土壤保持能力均最高的生态用地类型;5年间产水量和土壤保持量分别增加了32.16×10~6 m~3和17.69×10~6 t;产水量在海拔900 m地段,海拔越高增加量越少,土壤保持量在较低海拔有所增加;坡度越陡产水增加量越少,土壤保持量在各坡度均有增加。基于此研究结果,有助于选择优先建设的用地类型,使当地在保护源头水系和维持生态功能的同时发展冰雪运动。  相似文献   

17.
Most countries sharing the Amazon basin have signed the Ramsar Convention on Wetlands of International Importance but still lack complete wetland inventories, classification systems, and management plans. Amazonian wetlands vary considerably with respect to hydrology, water and soil fertility, vegetation cover, diversity in plant and animal species and primary and secondary productivity. Here, we propose a classification system of major natural habitats of Amazonian white-water river floodplains (várzeas) based on hydrological, water and soil chemistry and biological parameters. The Amazonian várzea is one of the largest Amazonian wetlands. It is exceptionally rich in plant and animal species and plays important roles in landscape history, evolution, hydrology and biogeochemical cycles of the Amazon basin. Most of Amazonia??s rural population lives in or along the várzea, emphasizing the economic importance of its natural resources. Our classification indicates five major systems, which are subdivided into 10 main habitats and up to 40 functional (vegetation) units of which the most important mesohabitats are described. We understand this classification as a dynamic system, as it is open to the inclusion of future research attempts and habitats without affecting the entire classification system. Our classification may be used for scientific purposes, such as comparative studies on biomass, productivity, biogeochemical cycles and biodiversity. Also, because the classification builds on habitat types and/or vegetation and functional units already distinguished by the local population it may be especially useful in guiding intelligent use of várzea habitat for specific management activities, such as agriculture, animal husbandry, forestry, fisheries, and conservation.  相似文献   

18.
小微湿地研究综述:定义、类型及生态系统服务   总被引:1,自引:0,他引:1  
崔丽娟  雷茵茹  张曼胤  李伟 《生态学报》2021,41(5):2077-2085
小微湿地作为一个"新兴"的概念,受到学者和政策制定者的日益关注。虽然小微湿地面积较小,但是却发挥着独特的生态功能。针对小微湿地的深入研究,有助于进一步拓展湿地科学的研究尺度,促进学科体系发展。介绍了小微湿地研究兴起的背景,总结了小微湿地的面积范围和分类体系,归纳了小微湿地的累加作用和景观特征,着重分析了小微湿地在维持关键物种种群、提供生物迁移踏脚石、调节雨洪、改善水质,以及营造城乡优美景观等方面提供的生态系统服务。提出未来需要进一步加强小微湿地生态过程和相关机理研究,将小微湿地建设与现行湿地保护体系和城乡生态环境建设有机结合,促进小微湿地建设的有序和可持续发展。  相似文献   

19.
In Estonia, as in other countries, the area of wetlands has diminished remarkably due to different utilization for economic needs. Comparatively large areas of natural wetlands have, however, been preserved. The country’s economic and political situation has changed rapidly since the regaining of independence in 1991 and accession to the European Union in 2004 brought about new challenges for the sustainable use of natural resources. This paper provides an update of conditions of wetlands in Estonia and, in part, represents an update of the relevant materials for Estonia that are described for the country when it was under the rule of the former USSR (Botch and Masing 1983, this volume). We review the diversity and status of wetlands in Estonia and describe the main problems and challenges of sustainable wetland use. Substantial progress has been achieved in Estonia in the area of wetland conservation and a significant proportion of valuable wetlands (a total of 33 wetland habitat types covering more than 300,000 ha) are legally protected and included in the integral and united system of protected areas. All Special Protection Areas and 80% of Special Conservation Areas in the Natura 2000 network represent a lesser or greater amount of wetland habitats. The main challenges of wetland preservation and use are: (1) management of drained wetland areas that have become sources of greenhouse gases; (2) attaining the sustainable use of peat resources and ensuring the restoration of cut-away peatlands; (3) maintenance of the traditional management of valuable semi-natural wetlands. In addition, the increasing pressure of various development projects and tourism on Estonia’s wetland resources need to be evaluated. Wetlands are also seen as an important basis for sustainable development and about 100 wetlands in Estonia that are used for primary or secondary treatment of wastewater. Energy production from wetland plant biomass is considered to be a promising source for small-scale heating plants.  相似文献   

20.
High levels of water-induced erosion in the transboundary Himalayan river basins are contributing to substantial changes in basin hydrology and inundation. Basin-wide information on erosion dynamics is needed for conservation planning, but field-based studies are limited. This study used remote sensing (RS) data and a geographic information system (GIS) to estimate the spatial distribution of soil erosion across the entire Koshi basin, to identify changes between 1990 and 2010, and to develop a conservation priority map. The revised universal soil loss equation (RUSLE) was used in an ArcGIS environment with rainfall erosivity, soil erodibility, slope length and steepness, cover-management, and support practice factors as primary parameters. The estimated annual erosion from the basin was around 40 million tonnes (40 million tonnes in 1990 and 42 million tonnes in 2010). The results were within the range of reported levels derived from isolated plot measurements and model estimates. Erosion risk was divided into eight classes from very low to extremely high and mapped to show the spatial pattern of soil erosion risk in the basin in 1990 and 2010. The erosion risk class remained unchanged between 1990 and 2010 in close to 87% of the study area, but increased over 9.0% of the area and decreased over 3.8%, indicating an overall worsening of the situation. Areas with a high and increasing risk of erosion were identified as priority areas for conservation. The study provides the first assessment of erosion dynamics at the basin level and provides a basis for identifying conservation priorities across the Koshi basin. The model has a good potential for application in similar river basins in the Himalayan region.  相似文献   

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