Managing mosquitoes without destroying wetlands: an eastern Australian approach

Recognising both the importance of intertidal wetlands and their role in mosquito-borne disease we discuss wise management to conserve wetland values and to reduce vector borne disease health risks. First we summarise the mosquito-borne diseases associated with intertidal wetlands in sub-tropical and tropical Australia. We consider the Ramsar Strategic Plan, its reflection in some key Australian statutes and the relationship between environment-focussed legislation and health legislation. This is followed by a brief overview of mosquito control and its impact on human health. Using a salt marsh example of an integrated process, we describe the development of what was, in the 1980s in Australia, a novel method of habitat modification (runnelling) for mosquito control. Runnelling modifies the tidal water flow on salt marshes, reducing mosquito larval numbers and minimising environmental impacts. The approach is related to two of the Ramsar goals (wise use and institutional capacity and effectiveness). We then describe the extension of its rationale to a complex mangrove system. Finally, with a concept model, we consider the convergence between minimal habitat modification for wetland conservation and human health protection using an interdisicplinary approach involving multiple stakeholders.     

生态伦理与湿地保护

生态伦理对于湿地保护的重要性主要体现为促进人类对湿地及其价值的正确认识、加强人类保护湿地的自我约束与社会舆论监督、提供制定和实施湿地保护法律法规的伦理基础。生态伦理对于湿地保护的要求主要体现在:人地伦理方面要求人类应当合理利用湿地资源、反对掠夺性的湿地开发、要特别保护湿地濒危野生动植物;代内伦理方面认为当代人在利用湿地资源、满足自身利益上的机会平等,对湿地资源的保护是全人类共同的责任与义务,要求地区之间、国家之间共同协作保护湿地;代际伦理方面要求当代人在对湿地资源开发利用时,应遵循责任原则、节约原则与慎行原则,防止给后代人造成不可挽回的损害。湿地保护伦理的培育途径主要有与湿地科学研究相结合、与湿地法律法规相结合、与社会实践活动相结合、与宣传教育相结合。     

图们江下游湿地生态系统健康评价

湿地是世界上具有独特结构与功能的生态系统,图们江流域湿地生态系统的健康对该区乃至东北亚地区综合生态系统网络的建设具有重要意义。选择图们江流域下游为研究区,基于压力-状态-响应(PSR)模型,在压力系统、状态系统、响应系统三个层面选取30个指标构建了图们江下游湿地生态系统健康评价指标体系,运用层次分析法和多级模糊综合评判法对研究区湿地生态健康状况进行综合评价,其结果为0.5878,处于亚健康状态。其中,压力系统的健康指数为0.5292,响应系统的健康指数为0.6866,状态系统的健康指数为0.5116,各等级隶属度S=(16.83%, 25.37%, 16.76%, 16.97%,24.07%)。主要表现在研究区域湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重;并且由于人为因素,湿地大面积退化,景观破碎化加剧,功能逐渐丧失,生产力水平下降;急需对本区域湿地进行保护与管理。     

我国湿地生态状况评价研究进展

从湿地生态状况评价定义、国际重要湿地和全国重点湿地生态状况和主要评价方法等方面研究综述了我国湿地生态状况评价。对全国1413处湿地生态状况的研究显示,国际重要湿地生态状况总体较好,重点湿地生态状况较差,生态状况差有341处,占24.85%,并系统分析了各类湿地生态状况评价的方法、内容和结果。认为湿地生态状况评价是满足湿地保护管理需求的一项基本技术研究工作,开展湿地生态状况评价可以从不同空间、时间尺度反映湿地生态变化趋势,满足湿地生态系统保护修复的管理要求,并揭示各生态因子的内在关系,是提高湿地的保护、管理和合理开发的重要技术手段。最后分析了当前湿地生态状况评价所面临的难点,并提出了相关对策建议。     

Wetlands and mosquitoes: a review

This review brings together information on mosquitoes, the diseases they transmit and the wetlands that provide habitats for the immature stages (eggs and larvae). Wetland values are mentioned, though the main literature on this does not generally overlap the mosquito issue. Mosquito management is overviewed to include: the use of larvicides, source reduction in intertidal wetlands and management in freshwater systems. There is not a great deal of information on mosquitoes and freshwater systems, except for constructed wetlands and they are considered separately. We then consider restoration mainly in the context of wetlands that have been the subject of habitat modification for mosquito control. Land use and climate change, as they affect mosquitoes and the diseases they transmit, are also reviewed, as this will affect wetlands via management activities. Finally the review addresses the critical issue of balancing health, both human and environmental, in an adaptive framework. It concludes that there is a need to ensure that both mosquito and wetland management communicate and integrate to sustain wetland and human health.     

Strategies for effective mosquito control in constructed treatment wetlands

Constructed wetlands hold considerable promise for providing water quality and wildlife habitat benefits. At the same time, constructed wetlands have been described as “mosquito-friendly habitats” and may raise potential conflicts with neighboring human populations. Conflicts arise because some design features, such as shallow water and emergent vegetation that are essential for optimizing water quality polishing, can result in undesirable increases in mosquito production. The attraction of large numbers of birds to constructed wetlands could also increase the risk of transmission of mosquito-borne viral infections to humans in the vicinity of the wetland. The potential for conflict is typically highest in arid regions where natural mosquito populations have limited abundance and are found near newly urbanizing areas.The creation of wildlife habitat is a significant goal of many treatment wetlands. Humans are also welcome in many treatment wetlands for recreational and educational activities. Risks of disease transmission to humans and livestock as well as the inconvenience of mosquitoes as pests must be offset by the economic savings of inexpensive water quality enhancement and the resulting reduction in pollution that also poses a risk to society’s health and well-being. Ecological risks associated with the use of mosquito control chemicals must be offset by the increased habitat benefits provided by these constructed wetlands. The right balance between these competing goals can be recognized by the design that provides the greatest net environmental and societal benefit. This paper describes these tradeoffs between mosquito control and the constructed wetland technology and provides a synthesis of information that can be used to optimize the benefits of these wetland systems. Basic research is recommended to better define the cost-effectiveness of the various design and management options.     

Responsible resource management: the predicament and reform path for Chinese wetland conservation

Despite national conservation policies, international agreements and public support related to wetlands, a wide range of agricultural development and public works projects have resulted in the over-exploitation and degradation of wetlands during the past decades in China. The phenomenon of “the tragedy of the commons” in Chinese wetland conservation is recognized as an incentive problem provoked by a multi-stakeholder situation. This paper examines the governance of China’s wetlands and its hierarchical and functional–behavioral characteristics within the context of resource management. The results show that the administrative system in China wetland management depends on resource element-oriented legislation, in that various agencies managing different resources place various demands on wetland resources. This paper analyzes the responsibilities and incentives of various government administrators and other stakeholders as well as their behavioral logic and why such a multi-stakeholder mode fails to provide adequate wetland conservation. Using Heilongjiang Province as an example, it explains the conflicts between stakeholders within both the legislative system and those who administer wetland management. In addition, it suggests improvements, especially in the form of an integrated management system with an appropriate and unified system of administration.     

Automatization and evaluation of a remote sensing-based indicator for wetland health assessment in East Africa on national and local scales

To avoid wetland degradation and promote sustainable wetlands use, decision-makers and managing institutions need quantified and spatially explicit information on wetland ecosystem condition for policy development and wetland management. Remote sensing holds a significant potential for wetland mapping, inventorying, and monitoring. The Wetland Use Intensity (WUI) indicator, which is not specific to a particular crop and which requires little ancillary data, is based on the Mean Absolute Spectral Dynamics (MASD), which is a cumulative measure of reflectance change across a time series of optical satellite images. It is sensitive to the compound effects of land cover changes caused by different agricultural practices, flooding or burning. The more frequent and intrusive management practices are on the land cover, the stronger the WUI signal. WUI thus serves as a surrogate indicator to measure pressure on wetland ecosystems.We developed a new and automated approach for WUI calculation that is implemented in the Google Earth Engine (GEE) cloud computing environment. Its automatic calculation, use of regular Sentinel-2 derived time series, and automatic cloud and cloud shadow masking renders WUI applicable for wetland management and produces high quality results with minimal user requirements, even under cloudy conditions. For the first time, we quantitatively tested the capacity of WUI to contribute to wetland health assessment in Rwanda on the national and local scale. On the national scale, we analyzed the discriminative power of WUI between different wetland management categories. On the local scale, we evaluated the possible contribution of WUI to a wetland ecosystem health scoring system. The results suggest that the adapted WUI indicator is informative, does not overlap with existing indicators, and is applicable for wetland management. The possibility to measure use intensity reliably and consistently over time with satellite data is useful to stakeholders in wetland management and wetland health monitoring, and can complement established field-based wetland health assessment frameworks.     

Impacts of human‐induced environmental change in wetlands on aquatic animals

Many wetlands harbour highly diverse biological communities and provide extensive ecosystem services; however, these important ecological features are being altered, degraded and destroyed around the world. Despite a wealth of research on how animals respond to anthropogenic changes to natural wetlands and how they use created wetlands, we lack a broad synthesis of these data. While some altered wetlands may provide vital habitat, others could pose a considerable risk to wildlife. This risk will be heightened if such wetlands are ecological traps – preferred habitats that confer lower fitness than another available habitat. Wetlands functioning as ecological traps could decrease both local and regional population persistence, and ultimately lead to extinctions. Most studies have examined how animals respond to changes in environmental conditions by measuring responses at the community and population levels, but studying ecological traps requires information on fitness and habitat preferences. Our current lack of knowledge of individual‐level responses may therefore limit our capacity to manage wetland ecosystems effectively since ecological traps require different management practices to mitigate potential consequences. We conducted a global meta‐analysis to characterise how animals respond to four key drivers of wetland alteration: agriculture, mining, restoration and urbanisation. Our overarching goal was to evaluate the ecological impacts of human alterations to wetland ecosystems, as well as identify current knowledge gaps that limit both the current understanding of these responses and effective wetland management. We extracted 1799 taxon‐specific response ratios from 271 studies across 29 countries. Community‐ (e.g. richness) and population‐level (e.g. density) measures within altered wetlands were largely comparable to those within reference wetlands. By contrast, individual fitness measures (e.g. survival) were often lower, highlighting the potential limitations of using only community‐ and population‐level measures to assess habitat quality. Only four studies provided habitat‐preference data, preventing investigation of the potential for altered wetlands to function as ecological traps. This is concerning because attempts to identify ecological traps may detect previously unidentified conservation risks. Although there was considerable variability amongst taxa, amphibians were typically the most sensitive taxon, and thus, may be a valuable bio‐indicator of wetland quality. Despite suffering reduced survival and reproduction, measures such as time to and mass at metamorphosis were similar between altered and reference wetlands, suggesting that quantifying metamorphosis‐related measures in isolation may not provide accurate information on habitat quality. Our review provides the most detailed evaluation to date of the ecological impacts of human alterations to wetland ecosystems. We emphasise that the role of wetlands in human‐altered ecosystems can be complex, as they may represent important habitat but also pose potential risks to animals. Reduced availability of natural wetlands is increasing the importance of altered wetlands for aquatic animals. Consequently, we need to define what represents habitat quality from the perspective of animals, and gain a greater understanding of the underlying mechanisms of habitat selection and how these factors could be manipulated. Furthermore, strategies to enhance the quality of these wetlands should be implemented to maximise their conservation potential.     

湿地生态系统健康评价指标体系 Ⅱ.方法与案例

湿地生态系统健康是一个非常复杂的问题,不同的湿地类型。衡量指标和标准也不尽相同,以三江平原挠力河域湿地作为案例研究,分析的湿地主要为闭合流域内的沼泽湿地和河缘湿地,以此为基础,确定三大类指标,即湿地生态特征指标,功能整合性指标和社会环境指标。在三大类指标内,又分别分出各自的具有可操作性的亚指标,因为健康是一个模糊概念,因此,根据模糊综合评判原理和方法,在对挠力河流域进行湿地分区的基础上,对各区的湿地进行了评价与比较排序,然后通过红绿灯信号系统对各区健康进行了预警。     

A comparison of created and natural wetlands in Pennsylvania,USA

Recent research suggests that created wetlands do not look, or function, like the natural systems they are intended to replace. Proper planning, construction, and the introduction of appropriate biotic material should initiate natural processes which continue indefinitely in a successful wetland creation project, with minimal human input. To determine if differences existed between created and natural wetlands, we compared soil matrix chroma, organic matter content, rock fragment content, bulk density, particle size distribution, vegetation species richness, total plant cover, and average wetland indicator status in created (n = 12) and natural (n = 14)wetlands in Pennsylvania (USA). Created wetlands ranged in age from two to 18 years. Soils in created wetlands had less organic matter content, greater bulk densities, higher matrix chroma, and more rock fragments than reference wetlands. Soils in reference wetlands had clay loam textures with high silt content, while sandy clay loam textures predominated in the created sites. Vegetation species richness and total cover were both greater in natural reference wetlands. Vegetation in created wetlands included a greater proportion of upland species than found in the reference wetlands. There were significant differences in soils and vegetation characteristics between younger and older created wetlands, though we could not say older created sites were trending towards the reference wetland condition. Updated site selection practices, more careful consideration of monitoring period lengths, and, especially, a stronger effort to recreate wetland types native to the region should result in increased similarity between created and natural wetlands.     

Wetland restoration to enhance biodiversity in urban areas: a comparative analysis

Wetlands mitigation for any activity can be applied to avoid or minimize damage and restore, enhance, or create wetlands as well. New tools for mitigating and creating wetlands are available, including the Wetland Impact Assessment. This article explores many current issues in wetland mitigation and mitigation strategies, using case studies for illustration. We include some general guidelines for successful wetland mitigation based primarily on existing literature review in several cities. We use comparison and analyses on biodiversity improvement and various wetland functions, including flood-risk management, linking people to nature through urban regeneration, and connecting with the natural environment. Also, restoration, enhancement, mitigation, and creation analyses are included.     

Hawaiian waterbird movement across a developed landscape

A key component for biologists managing mobile species is understanding where and when a species occurs at different locations and scaling management to fit the spatial and temporal patterns of movement. We established an automated radio-telemetry tracking network to document multi-year movement in 2016–2018 of 3 endangered waterbirds among wetlands on Oʻahu, Hawaiʻi, USA: ʻalae ʻula or Hawaiian gallinule (gallinule; Gallinula galeata sandvicensis), ʻalae keʻokeʻo or Hawaiian coot (coot; Fulica alai), and aeʻo or Hawaiian stilt (stilt; Himantopus mexicanus knudseni), each with different ecological requirements. There were marked differences in the movement propensity of the species, with no movement among sites detected in gallinules, 31% of coots moving among wetlands, and very high levels of daily movement in stilts. A network analysis revealed strong evidence for fidelity among individual stilts to specific wetlands, indicating different groups of wetlands supported different birds. There was also strong evidence for patterns in daily and seasonal movement patterns of stilts. Our work indicates the importance of each wetland to the waterbirds they support, as each individual had strong fidelity to a single wetland. In addition, for Hawaiian coots and stilts, which were documented moving among multiple wetlands, a network of wetlands may be key for long-term persistence of these endangered species, and coordinated regional management of waterbirds as a shared resource could provide greater benefits to waterbirds than independent management of each wetland.     

US Fish and Wildlife Service 1979 wetland classification: A review

In 1979 the US Fish and Wildlife Service published and adopted a classification of wetlands and deepwater habitats of the United States. The system was designed for use in a national inventory of wetlands. It was intended to be ecologically based, to furnish the mapping units needed for the inventory, and to provide national consistency in terminology and definition. We review the performance of the classification after 13 years of use. The definition of wetland is based on national lists of hydric soils and plants that occur in wetlands. Our experience suggests that wetland classifications must facilitate mapping and inventory because these data gathering functions are essential to management and preservation of the wetland resource, but the definitions and taxa must have ecological basis. The most serious problem faced in construction of the classification was lack of data for many of the diverse wetland types. Review of the performance of the classification suggests that, for the most part, it was successful in accomplishing its objectives, but that problem areas should be corrected and modification could strengthen its utility. The classification, at least in concept, could be applied outside the United States. Experience gained in use of the classification can furnish guidance as to pitfalls to be avoided in the wetland classification process.The US Government's right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

Tracking wetland loss to improve evidence-based wetland policy learning and decision making

At the core of any evidence-based policy analysis are accurate data and the policy analytic capacity of government agencies to use these data to develop and measure metrics of policy success. This study evaluated the government’s policy capacity to manage wetlands in Alberta, Canada, by measuring and evaluating three policy metrics: (1) no net change of wetland area; (2) permitted versus unpermitted wetland loss; and (3) an information tracking system that provides credible regulatory oversight. Using a climate-corrected wetland loss inventory, we detected the loss of 242 wetlands, totaling 71 ha, in the Beaverhill subwatershed between 1999 and 2009. The majority of the losses occurred on land that were classified as ‘developed’ (urban and industrial) or ‘agriculture’. When wetland loss was compared to government-issued wetland permit data, we found that over 80 % of the wetland area was lost without a government permit. The wetland permit data also revealed serious problems with information tracking by both government and non-government agencies responsible for policy and regulatory oversight. In order to resolve these common policy failures, governments need to commit more resources towards acquiring, effectively managing, and freely sharing information that can be used to evaluate policy outcomes to ‘open up’ wetland management and decision making to include active participation from informal institutions, local governments, and the general public as a means to drive improved regulatory oversight.     

湿地生物连通性影响因素及测度方法研究进展

湿地是地球上最多样化和最具生产力的生态系统之一,但近年来由于人类活动的频繁干扰,自然环境以前所未有的速度变化,两者的协同作用导致湿地呈现破碎化趋势。湿地的退化、转化使得湿地生物连通性减弱。良好的湿地生物连通性有利于湿地生态系统服务功能的维持、生物多样性的保护以及生物对气候变化适应水平的提高。因此理解、评估和保护生物连通性对于湿地生态系统而言至关重要。综述了湿地生物连通性的定义、总结了生物连通发生与变化的四个相互作用因子,从结构连通性、功能连通性两个测定角度,论述动物、植物和微生物三类研究对象生物连通性的测度方法,最后从湿地生物连通的时空尺度,连通与物质循环的耦合关系,湿地生物连通性评估分析模型改进角度提出了未来的研究方向,从而确保湿地生物连通网络的完整有效。可为湿地生物多样性、湿地保护和管理提供新的思路。     

Development of a multimetric plant-based index of biotic integrity for assessing the ecological state of forested,urban and agricultural natural wetlands of Jimma Highlands,Ethiopia

Wetlands are vital natural resources thereby providing ecological and socio-economic benefits to the people. However, anthropogenic activities have seriously changed the ecological conditions of wetlands worldwide, especially in developing nations like Ethiopia. Predominantly, the absence of biomonitoring tool greatly hampers the protection and management of wetlands. Therefore, the objective of this research is to develop a plant-based index of biological integrity for facilitating the management of wetlands. Accordingly, 122 plant species belonging to 37 families were collected and identified from forested, urban and agricultural wetland types and included in the analysis of the plant metrics. Initially, we reviewed and screened 35 potential metrics. Then, we selected four core metrics (% cover of native species, sensitive plant species richness, tolerant plant species richness and% of shrub species richness) using the decrease or increase responses to human disturbances, Mann-Whitney U test and redundant metric test. A trisect-quartile range system using box plots of the reference or impaired sites of wetlands was established to provide values for each core metrics. Then after, we combined the core metrics to develop the plant-based index of biological integrity. Finally, we validated the index by comparing the index response to different wetland types. Additionally, the index was validated based on the measured environmental variables that characterize the human disturbance gradient of wetlands. We found that the plant-based index is robust to discriminate the reference wetlands from impaired wetlands and can also be used as an effective tool for evaluating the long term natural wetland conditions of the Eastern African wetlands in the future.     

The role of constructed wetlands in secondary effluent treatment and water reuse in subtropical and arid Australia

Water reclamation and reuse is being actively promoted in Australia. In Queensland, surface-flow constructed wetlands with a diversity of macrophyte types offer the greatest potential for effluent polishing. Constructed wetlands in subtropical climates in coastal regions and arid climates in inland western regions are conducive to high macrophyte growth rates and nutrient removal, in particular nitrogen, producing an effluent suitable for irrigation, restoration of wetlands and/or release into natural waterways. Faecal-coliform removal is also high, producing effluent with <1000 cfu/100 mL and as low as 100 cfu/100 mL, acceptable for agricultural irrigation. Constructed wetlands can be designed to maximise the removal of both nutrients and pathogens by enhancing macrophyte diversity and natural disinfection processes by incorporating lagoons, shallow-water wetlands and subsurface-flow wetlands into the treatment train. Surface-flow wetlands can also be designed to minimise mosquito breeding by increasing macro-invertebrate predators, thereby alleviating community concerns about potential health risks. This paper addresses the role of constructed wetlands in nutrient and pathogen removal in Queensland's wetlands, and presents three case studies with respect to effluent reuse.     

推进生物多样性保护与人类健康的共同发展——One Health

随着新冠肺炎(COVID-19)的暴发, 野生动物、生物多样性和人类健康的关系再次引起广泛讨论。近20年来, 国际社会对于生物多样性与健康的研究日益增多, 并将它作为生物多样性保护与研究的重要方向之一。One Health作为一个新的理念框架, 通过交叉学科的研究和行动来推动包括人、所有其他动物及环境的健康。这个理念被不同国家、国际组织及协定所接纳及推广, 包括《生物多样性公约》等。本文通过总结近些年生物多样性对健康的影响方式、One Health的定义与发展历史、进入生物多样性议程的过程, 提出中国应用One Health改进相关野生动物管理以降低公共卫生危机的可能性的建议, 以及One Health框架内增强生物多样性保护所需的研究方向。One Health在中国的应用与发展应重视生物多样性研究和保护在其中的作用, 利用在景观生态学、群落内物种关系动态变化、气候变化影响、土地利用变化模式与趋势的研究, 与人类健康相结合, 提高One Health在应对公共健康和环境健康风险方面的准确性与及时性。同时, 需要加强我国在野生动物管理方面的投入和力度, 增强生物多样性保护与公共健康的联系, 将预警与干预措施前移, 减少疾病暴发带来的社会经济成本。     

Evaluation of ecosystem health for the coastal wetlands at the Yangtze Estuary, Shanghai

Despite the growing awareness of the important ecological functions and values provided by coastal and estuarine wetlands, wetland degradation continues worldwide due to increasing anthropogenic disturbances. Chongming Dongtan wetlands, adjacent to Shanghai, the largest city and industrial and trading port in China in rapid urban expansion and socioeconomic development are currently threatened with biodiversity reduction, wetland loss, contamination, and invasion of exotic plant. Sustainable protection and management of Dongtan Nature Reserve necessitate research to develop diagnostic tools and indicators for a comprehensive and objective assessment of wetland ecosystem health condition. Based on the pressure-state-response framework and ecological and environmental surveys at the Dongtan wetlands, an indicator system was established for evaluating the coastal wetlands ecosystem health, using indicators detected from satellite imagery and current field surveys. Through the establishment of health assessment units and spatial quantification of the indicators, the spatial clustering analysis, integrated with remote sensing and geographic information system technique was applied to make an accurate diagnosis of ecosystem health for Chongming Dongtan wetlands and highlight the areas in subhealthy and unhealthy condition and urgent need of conservation and management. The results from this research indicated that the ecosystem health condition at the Dongtan wetlands showed spatial variation, to a certain extent, corresponding to the distributions of elevation and land cover types. More than 75 % of the total study area was at a relatively healthy level, with 34.19 km² for the very healthy zone and 41.08 km² for the healthy zone, while the subhealthy and unhealthy zones covered 18.23 and 4.76 km², respectively. This study demonstrated the potential for this integrated approach to give objective and effective evaluation of ecosystem health for the dynamic coastal and estuarine wetlands and provide up-to-date information to assist with early warning for ecological security and management decisions for Chongming Dongtan Nature Reserve.