首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
  1. The catchments of the Great Barrier Reef (GBR) in Australia include more than one million ha of wetlands, which help to sustain the health and resilience of the reef.
  2. This article reviews the status, values, and threats of wetlands in the GBR catchments, as well as the management, protection, and challenges and opportunities for their restoration and rehabilitation.
  3. At present, wetlands in the GBR catchments have low rates of area loss and are generally well protected; however, they face major management challenges owing to the intensive land use of the catchments, especially for grazing, agriculture, horticulture, and mining. Major threats to these wetlands include water pollution, invasive species, changes in hydrology, and increasing temperature and salinity resulting from climate change.
  4. In recent years wetlands have been considered primarily for their role in improving water quality to ameliorate contaminated terrestrial run‐off to the GBR, with little attention given to their intrinsic value and other ecosystem services.
  5. Financial opportunities for wetland restoration in addition to government‐funded schemes include water pollution offsets, payment for ecosystem services, and nitrogen markets.
  6. Wetlands need to be protected, managed, and restored for the ecosystem services that they provide to the GBR, but also for their intrinsic value as significant features of coastal landscapes.
  相似文献   

2.
3.
4.
5.
6.
  • 1. The coastal area of Valencia (Spain) in the Western Mediterranean is rich in freshwater and brackish wetlands. These areas are mostly protected for bird conservation but are also highly affected by human impacts. Six shallow lakes located in Ramsar wetland sites of this area were studied in order to assess past and present ostracod biodiversity and relate it to the status of the lakes, taking into consideration the indicator value of these easily fossilizable crustaceans.
  • 2. In all the wetlands studied, ostracod taphocoenoses showed much higher species richness than the corresponding biocoenoses. This is expected from the time accumulative character of the taphocoenosis, but the trend is clearly evident in the most disturbed sites which indicated loss of ostracod diversity owing to human impacts.
  • 3. By considering the ecology of most frequent species, multivariate ordination of both tapho- and biocoenoses showed trends within and between lakes in their limnological status, which were related mainly to water chemistry, and also to temporality and eutrophication to a certain extent. Some lakes have apparently lost most of their past ostracod community owing to an increasing trophic status in some cases and to modifications of the hydrological regime in others.
Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

7.
  1. In many wetlands the timing and duration of inundation determine ecological characteristics and the provision of ecosystem services; however, wetland conservation decisions often rely on static maps of wetland boundaries that do not capture their dynamic hydrological variability and connectivity.
  2. The Amazon River basin contains some of the world's most extensive wetlands, many of which are floodplains where seasonal flood pulses result in a temporally varying inundation area and hydrological connectivity with river systems.
  3. This study classified Amazon wetlands according to the timing and duration (months per year) of inundation detected by remote sensing, and also investigated the contribution of precipitation regimes in affecting wetland distribution and hydrological dynamics.
  4. Permanently inundated wetlands account for the largest area and are mainly floodplains located in the lowlands of the catchment. Seasonally inundated wetlands varied greatly in the duration of inundation over the course of the year, ranging from 1 to 9 months. Distinct seasonal timing was detected among the large wetland complexes, reflecting rainfall regimes as well as time lags for drainage and drying. For example, inundation in the extensive Llanos de Moxos region of the southern Amazon was protracted and lasted well after the rainy season, compared with the Roraima region of the northern Amazon, where inundation was shorter and tracked the rainy season.
  5. The integration of inundation dynamics into wetland classification captures regional differences in timing and duration of inundation in the major wetlands of the basin that should be considered for conservation planning and other ecological applications. This information can aid regional wetland management and planning, especially with regards to minimizing the effects of dam and waterway construction that can directly affect the natural wetland dynamics. The use of global remotely sensed inundation data makes this approach easily transferable to other large tropical wetlands.
  相似文献   

8.
  • 1 Population and economic pressures necessitate the development of productive yet fragile wetland areas in some tropical developing countries. Owing largely to these same social and economic pressures, expertise for the design and implementation of sustainable development strategies is often limited in developing countries.
  • 2 Considerable relevant knowledge and experience exist in Europe and North America. Resource constraints limit the availability of this expertise in areas of need in the developing world, despite various international commitments to such cooperation.
  • 3 Knowledge-based systems technology is well suited for the transfer of expertise from specialists to non-specialist users. It may therefore represent a cost-effective solution for developed nations to honour their commitments to assist developing nations.
  • 4 SWAMP (Sustainable Wetland Areas Management Project) has been developed to support the National Wetlands Conservation and Management Programme in Uganda. Its purpose is to select appropriate combinations of sustainable uses for wetlands which may be under pressure for development to supply food, tradeable products, or other resources.
  • 5 SWAMP has the capability to be extended to tropical wetlands in general. In principle, SWAMP's architecture is equally applicable for supporting similar sustainable development initiatives in other types of ecosystem.
  相似文献   

9.
10.
  • 1. Rice field expansion is one of the activities associated with the disappearance of 90% of the wetlands in southern Brazil. Worldwide, rice agriculture has been recognized as having considerable potential value for many aquatic species. Nevertheless, management practices in such systems must be ameliorated and better investigated.
  • 2. This study evaluated the potential role of rice fields as refugia for amphibians, and whether different hydrologic management practices after rice cultivation could contribute to wetland amphibian conservation in southern Brazil.
  • 3. Six collections were made in six rice fields with different management practices after cultivation (three dry and three flooded) and three natural wetlands. The amphibians were sampled through six random 15‐min visual transects per collection in each rice field and the natural wetlands.
  • 4. In total, 2139 anuran individuals were observed in rice fields (798) and Reserva Lake (1341), comprising 12 anuran species distributed among five anuran families. Anuran richness and abundance varied over the rice cultivating cycle, and they were higher in the growing phases than in the fallow phases. The mean anuran richness and abundance was higher in Reserva Lake than in flooded and dry rice fields.
  • 5. The different management practices adopted after the harvesting period (presence or lack of surface water) did not influence the anuran richness and abundance. It did, however, influence species composition.
  • 6. The difference in species composition between the management practices adopted is an interesting result in terms of biodiversity conservation. Rice producers could maintain part of their agricultural land flooded during the fallow phase as a strategy to preserve a higher diversity of anurans. These results should be taken into consideration in wetland conservation plans in southern Brazil; however, the percentage of each agricultural land that should be kept flooded should be decided by Brazilian agricultural and conservation policies. Such a strategy would reconcile agricultural/economic needs with the conservation of biodiversity in southern Brazil, where more than 90% of wetland systems have already been lost. Copyright © 2009 John Wiley & Sons, Ltd.
  相似文献   

11.
  1. Wetlands are some of the most important ecosystems on Earth. They play a key role in mitigating climate change-related events and filtering polluted water, and provide habitats for a wide range of species. Despite their importance, and numerous regulations that support their conservation, wetlands continue to be destroyed. Recent reports have indicated a progressive decline in ecological character of remaining wetlands.
  2. This research reviews and extends the present status of wetland knowledge in Sardinia, the second largest Mediterranean island. For the first time, Sardinian wetlands were comprehensively mapped using satellite images and field validation. Impacts were also assessed. Trends in literature published about Sardinian wetlands since 1900 were then analysed, mainly according to the location(s) and topic(s) studied.
  3. In total, 2,501 Sardinian wetland sites were identified. The most common impacts observed in the field were vegetative degradation and water pollution. Of these wetlands, 2,274 have never been the subject of a research paper. Despite recent increases in publication rates, there was a lack of even basic knowledge about many wetlands, especially smaller ones. Larger wetlands have been studied from a range of viewpoints.
  4. In the light of these results, suggestions for improved awareness, effective management and conservation of Mediterranean wetlands were established. Future work should be directed to filling gaps in basic information, and to improvements in research and conservation, which might include multidisciplinary approaches in support of more comprehensive conservation management plans.
  相似文献   

12.
  1. The paper ‘Biodiversity values of remnant freshwater floodplain lagoons in agricultural catchments: evidence for fish of the Wet Tropics bioregion, northern Australia’, published in Aquatic Conservation: Marine and Freshwater Ecosystems in 2015, has contributed in several ways to the integration of freshwater wetland science within new catchment management policies and practices for Great Barrier Reef (GBR) sustainability.
  2. The Tully–Murray biodiversity study developed novel protocols to sample larval, juvenile, and adult fish life‐history stages in floodplain lagoons using a combination of boat‐based backpack electrofishing and fyke netting. In addition, hydrological and hydrodynamic models were applied in a completely new way to quantify the timing, extent, and duration of water connectivity across floodplain streams, cane drains, and wetlands. Combining the two novel approaches enabled an analysis of lagoon fish assemblage patterns in relation to environmental gradients, especially floodplain hydrology, connectivity patterns, and measures related to agricultural land use.
  3. In demonstrating the importance of different levels of connectivity for different biodiversity outcomes in freshwater floodplain lagoons of the Tully–Murray catchment, the subject paper established that floodplain connectivity needs to be taken into consideration in wetland management practices.
  4. The timing of the subject publication was fortuitous. It coincided with the preparation of the evidence‐based 2017 Scientific Consensus Statement on land‐based water quality impacts on the GBR. As one of the few freshwater wetland ecology publications for the catchments of the GBR at that time, this paper played an important role in demonstrating freshwater wetland values, fish conservation options, and management imperatives to sustain wetland ecological health and services in GBR catchments.
  5. By advancing the understanding of factors driving biodiversity patterns, and the importance of connectivity and ecohydrological processes in freshwater floodplain wetlands of the GBR catchment, the Tully–Murray study helped to drive new policy directives for the protection and restoration of catchment, floodplain, and estuary functions, and connectivity, now embedded in the Reef 2050 Long‐Term Sustainability Plan 2018, an overarching strategy for managing the GBR over the next 35 years, and complementary Queensland environmental legislation.
  相似文献   

13.
14.
15.
16.
  1. Natural wetlands emerge as the best sites to preserve the diversity of aquatic and riparian vegetation; however, especially in the lowlands, pristine wetlands and aquatic ecosystems have almost completely disappeared through land reclamation and agricultural development. Actions are needed, therefore, to maintain and recreate a wide network of wetlands able to preserve adequate levels of vegetation diversity.
  2. Focusing on a complex wetland system located in an overexploited plain, the article entitled ‘The importance of being natural in a human‐altered riverscape: Role of wetland type in supporting habitat heterogeneity and the functional diversity of vegetation’, published in 2016 in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) explored the role of wetland origin and hydrology as the main drivers of physical and vegetation functional diversity, following a hierarchical sampling approach.
  3. The main results reinforced the key contribution of natural sites in maintaining vegetation diversity in heavily impaired riverine contexts, suggesting a direct effect of the interannual and seasonal dynamics of water‐level variations in the observed vegetation patterns.
  4. The article offered an important contribution to our knowledge of vegetation patterns in wetlands, partly attributed to the innovative functional, hierarchical approach applied which is able to guarantee reliable data on the distribution patterns of physical heterogeneity and wetland vegetation.
  5. The findings of the article have been applied and adopted in a series of technical handbooks designed, inter alia, to support the monitoring programmes of habitats of community interest or vegetation of relevance for aquatic biodiversity conservation. In addition, this article has helped to raise awareness of the essential roles played by wetlands in agricultural landscapes and has emphasized the need for a better synergy between the European Habitats Directive and the Water Framework Directive. Several ecological recovery projects have been funded in line with the results described in the AQC article.
  相似文献   

17.
  • 1. Wetlands are declining worldwide, and there is a great need for their restoration and creation. One natural agent of wetland engineering is beavers, Castor spp., which have returned or are returning to many parts of their former range.
  • 2. We initially studied the facilitative effect of the beaver Castor canadensis on a waterbird community consisting of three waders and four ducks in boreal wetlands in southern Finland. Both waterbird species diversity and abundance increased when beavers impounded a pond. Common teal Anas crecca and green sandpiper Tringa ochropus were the species showing the most positive numerical response, but the other five species also increased upon flooding.
  • 3. This article evaluates how the results of the study have been used in management, both in theory and practice. The whole‐community facilitation concept has been taken up in numerous articles considering the restorative effects of beavers. It has also been used as ecological background when planning and executing man‐made wetland projects in Finland within both the public and the private sectors.
  • 4. Our study and its publication in Aquatic Conservation: Marine and Freshwater Ecosystems have set a foundation for further evidence‐based management of waterbird communities. As the results show, having beavers as wetland managers is a feasible tool for creating and restoring wetlands for waterbirds and other biota. Moreover, wetland restoration projects are becoming more popular endeavours, owing to an understanding of the diverse benefits of wetlands. Flooding by beavers is used as a model for managers when creating man‐made wetlands; for example, in urban areas where it is difficult to maintain beavers.
  相似文献   

18.
  • 1. Seasonal pasture wetlands are a common freshwater habitat in many agricultural landscapes, but their invertebrate diversity has rarely been examined compared with other freshwater habitats. Few studies have examined the role of seasonal wetlands for regional biodiversity or the pattern of change in assemblage composition across landscapes.
  • 2. Invertebrates were sampled from 16 naturally occurring seasonal wetlands and three perennial wetlands in south‐western Victoria, Australia. The wetlands were arranged in three clusters, separated by at least 20 km: two clusters each contained one perennial and four seasonal wetlands surrounded by pasture; the remaining cluster consisted of one perennial wetland and four seasonal wetlands on a property that has not been cleared of native vegetation, and four adjacent seasonal pasture wetlands cleared of native vegetation.
  • 3. Presence/absence data showed that seasonal wetlands had fewer taxa than perennial wetlands, but both were taxon rich. Turnover of taxa was high at all three scales, i.e. between samples within a wetland, between wetlands, and between wetland clusters, but each cluster did not have a characteristic assemblage composition. Up to two‐thirds of the invertebrate taxa found in perennial wetlands were also found in seasonal wetlands, showing that seasonal pasture wetlands could provide an expanded area of winter–spring habitat for many taxa.
  • 4. Seasonal pasture wetlands contribute to biodiversity in highly managed and depauperate agricultural landscapes. There was little regionalization of the fauna, taxon turnover was high and ranges appeared relatively continuous. Biodiversity in pasture wetlands was comparable to perennial non‐pasture wetlands elsewhere, despite being used for grazing livestock. This suggests that pasture wetlands may have substantial conservation value and should be managed to protect them from threatening processes such as drainage.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

19.
20.
  1. Wetlands are increasingly threatened by human activities worldwide. Genetic monitoring of associated wildlife provides valuable data to support their conservation. Waterbirds such as the wood stork (Mycteria americana) are good bioindicators of wetland disturbance and destruction.
  2. This study investigated past and contemporary levels of genetic diversity, differentiation and demographic processes in 236 wood storks from two major wetlands in Brazil in which breeding colonies are concentrated, using nine microsatellite loci and a 237‐bp untranslated fragment of the mitochondrial Control Region.
  3. Amapá populations (northern region) showed slightly higher levels of genetic diversity than Pantanal populations (central western region) and both populations had a low number of effective breeders.
  4. Results from assignment tests, F‐statistics, AMOVA, spatial and non‐spatial Bayesian clustering analyses support the hypothesis of gene flow among colonies within regions, but significant differentiation between regions.
  5. The better supported Bayesian coalescent models based on both markers indicated that the northern population exchanged migrants with unsampled populations, and that the central western population was founded by individuals from the north. Mitochondrial estimates revealed that the timing of population divergence broadly overlapped the Last Glacial Maximum (LGM), and that the central western population expanded more recently than the northern population.
  6. The results support the hypothesis that the coastal wetlands in northern Brazil remained stable enough to shelter large wood stork populations during the LGM and storks colonized freshwater wetlands in the central western region following deglacial warming.
  7. Conservation policies and protective measures should consider Amapá and Pantanal wood stork populations as genetically differentiated units and priority should be given to Amapá populations that represent the source gene pool. Continuous genetic monitoring of wood storks would help detect genetic signs of changes in demographic trends that may reflect alterations or degradation in wetlands.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号