长江中下游升金湖湿地越冬鸭属(Anas)鸟类群落结构和行为特征

升金湖是长江中下游地区典型的浅水通江湖泊,是东亚-澳大利西亚候鸟迁徙路线上水鸟重要的越冬地. 2017年11月-2018年3月,以该湖泊越冬鸭属(Anas)鸟类为研究对象,对其在芦苇湿地、芡实塘、退耕还湿和水生植被恢复湿地4种湿地生境中的群落结构、行为特征及其环境影响因素进行了研究. 结果表明,升金湖分布有10种越冬鸭属鸟类,斑嘴鸭(Anas poecilorhyncha)、绿翅鸭(A. crecca)和绿头鸭(A. platyrhynchos)为该属鸟类群落的优势种. 鸭属鸟类群落在越冬前期种类和数量最多,在整个越冬期,鸭属鸟类在芦苇湿地中种数、数量、密度和多样性指数最高. 在水生植物盖度高、人为活动弱的芦苇湿地,鸭类的主要行为是休息;在食物资源丰富、人为活动强的芡实塘和退耕还湿湿地,其主要行为是觅食和警戒. 鸭属鸟类群落种数、数量、密度和多样性指数与湿地的面积、水域面积、水生植物盖度呈正相关,与干扰度和水深呈负相关. 觅食时间与气温和沉水植物的盖度呈正相关,与水深和干扰度呈负相关,警戒时间与干扰度呈正相关,与挺水植物的盖度呈负相关. 各种恢复类型的湿地生境成为越冬鸭属鸟类的重要栖息地,因此恢复多种湿地栖息地对于越冬水鸟的保护具有重要意义.     

鄱阳湖夏季极端水位条件下越冬水鸟多样性、空间分布及其保护对策

鄱阳湖是我国最大的淡水湖,也是具有国际意义的候鸟越冬地. 近年来,鄱阳湖水文情势异常使得候鸟越冬环境更加复杂. 本文以2020年鄱阳湖出现夏季极端水位为背景,基于2019和2020年鄱阳湖越冬水鸟同步调查数据,探讨了夏季极端水位对越冬水鸟丰富度和空间分布的影响. 研究结果表明：夏季极端水位条件下鄱阳湖越冬水鸟的总数量、群落结构和优势物种组成相对稳定,水鸟数量由597307只下降至572358只,主要是鸭科、鸥科、鹳科、鸬鹚科和鹮科鸟类数量明显下降;食块茎、食种子和食鱼集团水鸟数量均有所下降. 水鸟的整体空间分布格局变化不大,主要栖息地仍为鄱阳湖保护区和上饶湿地的碟形湖及人控湖汊,越冬水鸟向人工湿地扩散加剧. 2019年在人工湿地主要记录到灰鹤926只、白鹤3只;2020年则记录到白鹤2215只、灰鹤7294只、白头鹤88只、白枕鹤378只、豆雁550只、鸿雁3100只、灰雁3200只和小天鹅1543只. 2020年冬季人工湿地中的越冬水鸟数量比2019年增加显著. 鄱阳湖夏季极端水位导致沉水植物群落崩溃,造成植食性水鸟在天然湿地中的越冬食物短缺,从而导致种群空间分布格局出现明显变化,这也是鹤类和雁类水鸟前往人工湿地觅食的主要原因. 因此,在夏季洪水频发的背景下加强人工湿地管理,是当前解决越冬水鸟天然湿地食物资源短缺的重要措施.     

Wetlands with controlled drainage and sub‐irrigation systems—modelling of the water balance

Over the past centuries, the agricultural use of wetlands in Central Europe has required interference with the natural wetland water balance. Often this has consisted of drainage measures alone. In low‐precipitation areas, it has also involved the operation of combined drainage and sub‐irrigation systems. Model studies conducted as part of planning processes, or with a view to finding out the impact of changing climate conditions on the water balance of wetlands, must take these facts into account. For this reason, a water balance model has been devised for wetlands whose water balance is governed by water resources management systems. It is based on the WBalMo model system. Special modules were integrated into WBalMo to calculate the water balance of wetland areas (WABI module) and to regulate inflow partitioning within the wetland (REGINF module). When calculating the water balance, the WABI module takes into account precipitation and potential evapotranspiration, groundwater levels below surface, soil types, land‐use classes, inflows via the running water system, and data for target water levels. It provides actual evapotranspiration, discharge into the running water system, and groundwater levels in the area. The example of the Spreewald, a major wetland area in north‐eastern Germany, was used to design and test the WBalMo Spreewald model. The comparison of measured and calculated water balance parameters of the wetland area confirms the suitability of the model for water balance studies in wetlands with complex water resources management systems. The results reveal the strong influence of water management on the water balance of such areas. The model system has proved to be excellently suited for planning and carrying out water management measures aimed at the sustainable development of wetlands. Furthermore, scenario analyses can be used to assess the impact of global change on the water balance of wetlands. Copyright © 2006 John Wiley & Sons, Ltd.     

东洞庭湖4种濒危鹤类近30年种群动态及栖息地景观格局变化

东洞庭湖是4种濒危鹤类：白头鹤（Grus monacha）、白枕鹤（G.vipio）、白鹤（G.leucogeranus）和灰鹤（G.grus）的越冬地,但尚无东洞庭湖越冬鹤类种群动态及栖息地变化的系统研究.本研究调查收集了近30年来东洞庭湖4种鹤类的种群状况,并选取相应越冬季的东洞庭湖卫星图片,提取不同时期东洞庭湖湿地景观格局数据,分析鹤类种群动态与湿地景观格局之间的关联.结果表明：近30年来,东洞庭湖4种濒危鹤类种群数量均呈不同程度的下降.目前4种鹤类集中分布于采桑湖、丁字堤一带,灰鹤种群数量尚维持有二百余只,而白头鹤、白枕鹤和白鹤仅有不足10只的零星分布.1999-2000年后东洞庭湖水域及泥滩面积迅速下降并快速破碎化是导致鹤类种群下降的重要原因.未来应从保护及恢复东洞庭湖鹤类栖息地入手,加大鹤类保护,逐渐恢复东洞庭湖鹤类种群.     

Current state of knowledge regarding South America wetlands and their future under global climate change

The exact size of the wetland area of South America is not known but may comprise as much as 20% of the sub-continent, with river floodplains and intermittent interfluvial wetlands as the most prominent types. A few wetland areas have been well studied, whereas little is known about others, including some that are very large. Despite the fact that most South American countries have signed the Ramsar convention, efforts to elaborate basic data have been insufficient, thereby hindering the formulation of a wetland-friendly policy allowing the sustainable management of these areas. Until now, the low population density in many wetland areas has provided a high level of protection; however, the pressure on wetland integrity is increasing, mainly as a result of land reclamation for agriculture and animal ranching, infrastructure building, pollution, mining activities, and the construction of hydroelectric power plants. The Intergovernmental Panel on Climate Change has predicted increasing temperatures, accelerated melting of the glaciers in Patagonia and the Andes, a rise in sea level of 20–60 cm, and an increase in extreme multiannual and short-term climate events (El Niño and La Niña, heavy rains and droughts, heat waves). Precipitation may decrease slightly near the Caribbean coast as well as over large parts of Brazil, Chile, and Patagonia, but increase in Colombia, Ecuador, and Peru, around the equator, and in southeastern South America. Of even greater impact may be a change in rainfall distribution, with precipitation increasing during the rainy season and decreasing during the dry season. There is no doubt that the predicted changes in global climate will strongly affect South American wetlands, mainly those with a low hydrologic buffer capacity. However, for the coming decades, wetland destruction by wetland-unfriendly development planning will by far outweigh the negative impacts of global climate change. South American governments must bear in mind that there are many benefits that wetlands bring about for the landscape and biodiversity as well as for humans. While water availability will be the key problem for the continent’s cities and agroindustries, intact wetlands can play a major role in storing water, buffering river and stream discharges, and recharging subterranean aquifers.     

Suitability mapping of global wetland areas and validation with remotely sensed data

With increasing urbanization and agricultural expansion, large tracts of wetlands have been either disturbed or converted to other uses. To protect wetlands, accurate distribution maps are needed. However, because of the dramatic diversity of wetlands and difficulties in field work, wetland mapping on a large spatial scale is very difficult to do. Until recently there were only a few high resolution global wetland distribution datasets developed for wetland protection and restoration. In this paper, we used hydrologic and climatic variables in combination with Compound Topographic Index(CTI) data in modeling the average annual water table depth at 30 arc-second grids over the continental areas of the world except for Antarctica. The water table depth data were modeled without considering influences of anthropogenic activities. We adopted a relationship between potential wetland distribution and water table depth to develop the global wetland suitability distribution dataset. The modeling results showed that the total area of global wetland reached 3.316×107 km2. Remote-sensing-based validation based on a compilation of wetland areas from multiple sources indicates that the overall accuracy of our product is 83.7%. This result can be used as the basis for mapping the actual global wetland distribution. Because the modeling process did not account for the impact of anthropogenic water management such as irrigation and reservoir construction over suitable wetland areas, our result represents the upper bound of wetland areas when compared with some other global wetland datasets. Our method requires relatively fewer datasets and has a higher accuracy than a recently developed global wetland dataset.     

FEUWAnet: a multi-box water level and lateral exchange model for riparian wetlands

Riparian wetlands as typical aquatic-terrestrial interfaces control, in a very specific way, nonpoint water and related chemical fluxes exchanging between catchment areas to their respective water systems (streams, lakes). The existing groundwater and soilwater flow models reveal gaps in dealing with the complex behaviour of processes and the considerable spatial and temporal heterogeneity of riparian wetlands. Based on long-term experience gained through field observations and the interpretation of model produced data, a multi-box aggregation of processes which determines lateral as well as vertical flows and, as a whole, water balance, is used to discretise a generic riparian wetland transect situated between an upland aquifer and a receiving water body.

The resulting mathematical model, FEUWAnet, endowed also with an original methodology to adapt parameters, has been applied to a riparian alder wetland adjacent to Lake Belau (northern Germany). Results of simulations illustrate a good fit between calculated water levels and observed values and an accordance of calculated water balance to previous independent evaluations. This confirms that the sound simplifications of real situations performed by the FEUWAnet mathematical model are a promising way to deal with hydrological complexity of riparian zones. Moreover, FEUWAnet permits, to a certain extent, one to unravel the spatial heterogeneity and temporal variation of lateral (from catchment area to water systems) and vertical (from canopy to groundwater zone) water fluxes typical of riparian ecosystems: this is the necessary step to undertake when developing integrated models capable of assessing the effectiveness of riparian systems in controlling the fluxes of nonpoint pollution discharging in the open water bodies.     

冬季安徽菜子湖水位变化对主要湿地类型及冬候鸟生境的影响

“引江济淮”工程调度运行后,水位抬升将影响越冬候鸟适宜生境（泥滩地和草本沼泽）的出露,并进而影响湿地植物和底栖生物出露程度,对越冬候鸟的栖息环境和食物可及性产生不利影响,尤其是影响到挖掘啄取集团和浅水取食集团的越冬水鸟.基于安徽菜子湖不同水位对应的遥感影像解译结果,分析了水位变化对菜子湖泥滩地和草本沼泽出露的影响,并构建了菜子湖主要湿地类型的面积对水位响应的函数关系.结果表明：候鸟越冬期菜子湖泥滩地和草本沼泽面积与水位均呈极显著负相关.当水位到达8.1和8.6 m时,菜子湖将分别减少约16.8%和10.0%以及30.4%和22.2%的泥滩地和草本沼泽.1956-2015年候鸟越冬期各月水位的变化趋势及水位大于8.1 m的机率分析表明,工程调度运行会对菜子湖生态水文过程产生一定影响.结果可为模拟不同水位对菜子湖主要湿地类型及面积的影响提供依据,并从工程的角度为菜子湖水位优化调度提供科学依据.但由于数据缺乏,未全面阐述湿地类型面积和生境的关系,研究存在一定的局限性.建议加强菜子湖候鸟越冬期生境适应性调度研究及生态环境监测,进一步掌握菜子湖越冬候鸟适宜生境及重要越冬水鸟种群数量和分布格局对水位变化的响应,用科学实验和生态环境监测数据来加强菜子湖水位优化调度.     

基于越冬水鸟生境模拟的拟建鄱阳湖水利枢纽生态控制水位探讨

长江及鄱阳湖水系上游水库群运用后鄱阳湖枯季水文节律出现新的变化,为应对新的枯水情势,鄱阳湖水利枢纽作为一个选项被提出,如何确定其适宜的调控水位才能维持鄱阳湖湿地生态系统健康是其中的重点与难点.本文选择鹤类、小天鹅、鸿雁等食植物块茎水鸟作为鄱阳湖湿地生态系统的指示物种,基于EFDC水动力学模型和生境适宜度曲线构建了鄱阳湖越冬水鸟生境数值模拟模型;从食物资源与取食可及性两个方面,分苦草(Vallisneria natans)生长期和水鸟越冬期两个时段,以水深作为关键生境因子,对近10年鄱阳湖苦草及水鸟取食潜在生境面积变化进行了连续模拟;揭示了鄱阳湖苦草及水鸟取食潜在生境面积随水位的变化规律并构建了定量响应函数:苦草潜在生境面积随水位呈单峰型变化,在星子站水位为14.8 m时达到最大,约为1703 km2;越冬水鸟取食潜在生境面积随水位呈三段式变化,最大和最小面积分别约为564和476 km2,相应星子站水位分别为11.73和9.56 m.在此基础上,针对拟建的鄱阳湖水利枢纽工程,基于不同调度分期内生境保护目标的差异确定了符合天然水位波动特征的生态水位动态调控方案:下闸蓄水期内水位宜控制在16 m以下,后续根据越冬水鸟迁入情况逐步下降以增加取食生境面积,在12月次年1月的越冬水鸟数量峰值期水位宜控制在12.5 m以下,后续根据来水情况逐步过渡至江湖连通期的自然状态.成果从保护越冬水鸟食物资源与取食可及性两个方面提出了鄱阳湖水利枢纽生态水位的动态调控阈值,为江湖新水沙条件下鄱阳湖湿地生态系统保育提供了量化依据.     

Landscape and climate change threats to wetlands of North and Central America

North and Central America has a combined total of 2.5 million km² of wetlands, with 51 % in Canada, 46 % in the USA, and the remainder in subtropical and tropical Mexico and Central America. Loss rates are well known for the conterminous USA and for parts of Canada but poorly understood for Mexico and Central America. Wetlands of North America continue to be threatened due to drainage for agriculture and urban development, extreme coastal and river management, water pollution from upstream watersheds, peat mining, waterfowl management, and more recently climate change. Human use of wetlands in this region are many, including receiving ecosystem services such as water purification, flood regulation, climate regulation, and direct provisioning benefits for many cultures living in and among wetlands, especially in the Louisiana Delta and in Mexico and Central America. Climate change affects will cause wetland impacts on coastal wetlands due to sea level rise and on inland wetlands due to changes in precipitation, air temperature, and river discharges. Wetlands, in turn, have a major role in the storage of carbon in boreal regions of Canada and with carbon sequestration in temperate and tropical wetlands of the Americas.     

Mobility-dependent response of aquatic animal species richness to a wetland network in an agricultural landscape

Management of wetland connectivity is important for biodiversity conservation. In the modern agricultural landscape, the natural connections between floodplain wetlands have been greatly altered. Agricultural ditches and channelized streams are widely distributed in floodplains, which may contribute to the maintenance of wetland connectivity and biodiversity. To determine how these watercourse networks affect wetland biodiversity, we examined the relationship between the species richness of aquatic animals and wetland connectivity, with a special focus on species mobility. From July to August 2011, fish and aquatic insects were collected from 24 wetlands in northern Japan. To determine the degree of wetland connectivity, we assessed the relative importance of individual wetlands in maintaining the entire wetland network using two connectivity indices: hydrologic connectivity via watercourses and spatial connectivity defined as Euclidian distances between wetlands using graph theory. We found that only high mobility groups of both taxa could enhance species richness in either a hydrologic (fish) or spatial (insect) wetland network. The species richness of insects with high-flying ability was found to increase as spatial connectivity increased. Furthermore, the species richness of fish with high-swimming ability was positively influenced by hydrologic connectivity, most likely because highly mobile species were able to reach suitable habitats and migrate from source populations in a wetland network owing to their good mobility. Our findings indicate that hydrologic network is important for maintaining biodiversity as well as spatial connectivity. It is important to focus conservation efforts on key wetlands with high hydrologic and spatial connectivity in future wetland management.     

The stereoscopic spatial connectivity of wetland ecosystems: Evaluation method and regulation measures

Currently, the weakened connectivity of wetland ecosystems is the most important factor leading to the destruction, degradation, and disappearance of wetlands. Studying changes in wetland ecosystems connectivity enables the understanding the hydrological processes in wetland ecosystems and provides significant support for the study of ecological water demand. However, recent research on the connectivity of wetland ecosystems has primarily focused on intuitive Heilongjiang River Basin in China (HRBC) connectivity in terms of hydrology and geomorphology, while the impact of wetland ecosystems on habitats has been ignored. The present study applied an innovative method to evaluate and regulate the stereoscopic spatial connectivity (SSC) of the wetland ecosystems in the HRBC. In this method, the water requirements of typical organisms in the region were considered, and the hydrological trends in the wetland ecosystems along with the status of the SSC were analysed using remote sensing images. A regulation mode for improving the stereoscopic spatial connectivity index (SSCI) was proposed. The results revealed that over the past 35 years, the wetland ecosystems in the study area shrank significantly, with the SSCI decreasing from 41.30% in 1980 to 35.08% in 2015. By comparing the correlations among temperature, precipitation, agricultural land, construction land, and the wetland ecosystems during the same period, it was proven that human activity serves as the major driving force behind the observed loss of wetlands in the system. Subsequently, the key protected areas needing protection to maintain the SSC of the wetland ecosystems were clarified, and the key recovery areas were determined based on three scenarios featuring high, medium, and low feasibility, which greatly improved the SSCI and generalization route after regulation. In general, the proposed SSC evaluation and regulation method is widely applicable to all kinds of wetland ecosystems located on animal habitat and migration routes, which can fully reflect the ecological effects of wetland ecosystems, and this method has certain reference significance for the evaluation and regulation of wetland ecosystems in other regions.     

Wetlands of Northeast Asia and High Asia: an overview

This review reports background information on wetlands in the Northeast Asia and High Asia areas, including wetland coverage and type, significance for local populations, and threats to their vitality and protection, with particular focus on the relationship of how global change influenced wetlands. Natural wetlands in these areas have been greatly depleted and degraded, largely due to global climate change, drainage and conversion to agriculture and silviculture, hydrologic alterations, exotics invasions, and misguided management policies. Global warming has caused wetland and ice-sheet loss in High Asia and permafrost thawing in tundra wetlands in Northeast Asia, and hence induced enormous reductions in water-storage sources in High Asia and carbon loss in Northeast Asia. This, in the long term, will exacerbate chronic water shortage and positively feed back global warming. Recently, better understanding of the vital role of healthy wetland ecosystems to Asia’s sustainable economic development has led to major efforts in wetland conservation and restoration. Nonetheless, collaborative efforts to restore and protect the wetlands must involve not only the countries of Northeast and High Asia but also international agencies. Research has been productive but the results should be more effectively integrated with policy-making and wetland restoration practices under future climatic scenarios.     

Modelling groundwater/surface water interaction in a managed riparian chalk valley wetland

Understanding hydrological processes in wetlands may be complicated by management practices and complex groundwater/surface water interactions. This is especially true for wetlands underlain by permeable geology, such as chalk. In this study, the physically based, distributed model MIKE SHE is used to simulate hydrological processes at the Centre for Ecology and Hydrology River Lambourn Observatory, Boxford, Berkshire, UK. This comprises a 10‐ha lowland, chalk valley bottom, riparian wetland designated for its conservation value and scientific interest. Channel management and a compound geology exert important, but to date not completely understood, influences upon hydrological conditions. Model calibration and validation were based upon comparisons of observed and simulated groundwater heads and channel stages over an equally split 20‐month period. Model results are generally consistent with field observations and include short‐term responses to events as well as longer‐term seasonal trends. An intrinsic difficulty in representing compressible, anisotropic soils limited otherwise excellent performance in some areas. Hydrological processes in the wetland are dominated by the interaction between groundwater and surface water. Channel stage provides head boundaries for broad water levels across the wetland, whilst areas of groundwater upwelling control discrete head elevations. A relic surface drainage network confines flooding extents and routes seepage to the main channels. In‐channel macrophyte growth and its management have an acute effect on water levels and the proportional contribution of groundwater and surface water. The implications of model results for management of conservation species and their associated habitats are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

New mapping techniques to estimate the preferential loss of small wetlands on prairie landscapes

Reliable estimates of wetland loss require improved wetland inventories and effective monitoring programmes. The Prairie Pothole Region of North America is experiencing rapid urban, agricultural and economic development, which places wetlands at risk, especially small geographically isolated wetlands. This loss is concomitant with a loss of ecosystem services. To improve upon current wetland inventories, a method for mapping wetlands using an automated object‐based approach was developed for a regional watershed in Alberta. The method improves upon existing wetland mapping methods by effectively mapping small wetlands and better capturing the convolution of wetland edges. This approach uses digital terrain objects derived from light detection and ranging data, from which 130 157 wetlands were identified. Wetland loss estimates (% number and % area) were obtained by applying a wetland area versus frequency power‐law function to the wetland inventory. We estimated a 16.2% historic loss of wetland number and a 2.6% loss of wetland area, with the size of these lost wetlands <0.04 ha. The improved techniques for mapping wetland loss and estimating wetland loss provide a more accurate representation of the magnitude of wetland loss in the Prairie Pothole Region. Copyright © 2015 John Wiley & Sons, Ltd.     

Is net ecosystem production higher in natural relative to constructed wetlands?

Ecosystem metabolism is an important measure of wetland restoration efficiency, and serves to indicate if the system is capable of processing energetic resources. Despite its value, ecosystem metabolism has rarely been included in monitoring programs. In this study, we aimed to achieve the following objectives: (i) compare net ecosystem production (NEP) rates of constructed vs. natural wetlands; (ii) identify the highest NEP rate habitats; and (iii) define the main environmental factors regulating NEP in different wetland types. Pelagic and benthic NEP rates and physicochemical features were measured in three natural and five constructed wetlands in the middle Ebro River floodplain (NE Spain). Statistical analyses showed pelagic NEP rates peaked in natural wetlands, which produced up to 187.5 mg C m^?3 h^?1 compared to lower rates in constructed wetlands (up to 46.2 mg C m^?3 h^?1). Pelagic NEP responded positively to temperature, total dissolved solids, and nutrients. Benthic NEP rates were 3 to 30-fold greater than pelagic in natural (up to 994.9 mg C m^?3 h^?1) and constructed (up to 1,551.5 mg C m^?3 h^?1) wetlands, and were heavily influenced by habitat type, with NEP peaking in areas dominated by submerged vegetation and fine organic sediment. Rapid recovery in aquatic communities (i.e. macroinvertebrate diversity) has been previously reported for the studied wetlands; however, our study suggests a slower recovery of functional processes (i.e. pelagic NEP) in constructed habitats. We therefore strongly advocate the inclusion of ecosystem function in the design and evaluation of restoration projects to optimise long-term wetland ecosystem sustainability.     

湖泊湿地水文过程研究进展

湖泊湿地是世界上最重要的生态系统之一,在调蓄洪水、净化环境、保护生物多样性以及为人类提供淡水和食物等方面发挥着不可替代的作用.然而,受气候变化和人类活动叠加影响,湖泊湿地水文过程发生了剧烈变化,湖泊湿地面临着面积萎缩、质量下降和服务功能退化等风险.本文总结了原位观测、数值模拟和遥感技术在获取湖泊湿地关键水文要素方面的优...     

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