Open-source based geo-platform to support management of wetlands and biodiversity in Quebec

Wetlands are one of the most productive environments in the world. Despite their importance for water and carbon cycle regulation, wildlife survival and economic value, human activities along with severe climate changes have led to critical loss and degradation of these ecosystems. In Canada, where these lands still occupy a notable percentage of the territory (~ 14%), efficient strategies and public awareness measures to protect them are required. The Open Government program fosters accessibility to a large amount of data for developing approaches and applications that contribute to this purpose. Web cartographic implementations represent a potential tool for integration and diffusion of diversified information that can support the protection of natural habitats.In this paper, we present an open-source geo-platform that supports multi-scale management of wetlands and biodiversity in Quebec. This friendly and dynamic prototype allows integration of multisource data, providing, as well, the possibility of geovisualization and correlation analysis of possible stressors impacting these ecosystems. This system proposes useful and easy-to-use functionalities that can facilitate identification of possible habitats in danger. The prototype proposed is flexible and can be adapted to assist other biodiversity studies as well as the practical needs of responsible groups such as planners, conservationists and landscape managers.     

Agricultural ponds as alternative habitat for waterbirds: spatial and temporal patterns of abundance and management strategies

The progressive lost of natural wetlands as a consequence of human activities has lead to the use of new habitats by the species linked to water presence. In Southeast Spain, thousands of irrigation ponds have been lately constructed to store water for agriculture and are used by waterbirds as an alternative habitat. For this study, breeding and wintering waterbirds were counted in a subset of irrigation ponds between 2002 and 2007. Breeding communities were more abundant than wintering communities, but they presented a similar richness and diversity. The ponds were selected by waterbirds according to their characteristics, and breeding communities were more selective than wintering communities. Our results enhance the importance of pond size (area), connectivity (distance to the nearest wetland) and habitat quality (resource offer and construction material) in the pond selection process. The presence and design of these impoundments could be playing a crucial role for some waterbirds species. Therefore, the long-term information provided here can be useful for establishing management strategies for these artificial wetlands.     

Historical surveys reveal a long‐term decline in muskrat populations

The muskrat (Ondatra zibethicus) is an iconic species in Canada, valued for both its fur and its integral role in wetland ecosystems, and widely regarded for its perseverance. However, the resilience of this semiaquatic mammal seems to be in question now as increasing evidence points to widespread population declines. Recent analyses of harvest data across North America suggest a reduction in their numbers, but this has not been widely corroborated by population surveys. In this study we replicated historic muskrat house count surveys at two large Great Lakes coastal wetlands and present confirmation that declines in muskrat harvest correspond to actual declines in muskrat abundance. At the Point Pelee National Park marsh and the Matchedash Bay‐Gray Marsh wetland we found that mean muskrat house counts declined by 93% and 91% respectively between historic surveys 40–50 yrs ago and contemporary surveys over the past 7 yrs. The factors responsible for these dramatic declines remain unclear but there may be a relationship with changes in the habitat quality of these wetlands that have occurred over the same time frame. Not only is the loss of muskrats an issue for the resulting loss of the wetland ecosystem services they provide, but it may be an indication of broader marsh ecosystem degradation. As such, a scarcity of muskrats should be considered a red flag for the state of biodiversity in our wetlands. Continued surveys and ongoing research are needed to shed more light on the current status of muskrat populations and their marsh habitats across their native range.     

Assessing the ecological integrity of endorheic wetlands,with focus on Mediterranean temporary ponds

EU countries are required to perform an assessment of all freshwater habitats larger than 50 ha by 2015 to meet the requirements set by the Water Framework Directive (2000). To achieve this, an array of indicators and multimetric indices has been developed to monitor European waters. In general, these indicators are developed for large water bodies, while they are still largely lacking for smaller wetlands. This is in contrast with the conservation value, valuable ecosystem services and the often unique biodiversity of these systems, and the fact that like large (>50 ha) wetlands they are also covered by the Ramsar Convention. In (semi) arid regions, such as the Mediterranean basin, small water bodies are often of a temporary nature, are abundant and provide an important source of water for the local people, their livestock and agriculture. The quantity and quality of temporary wetlands are, however, decreasing at an alarming rate worldwide. Although some monitoring techniques were recently proposed, there is still an urgent need for a consistent policy and a user friendly set of monitoring tools for temporary wetlands that can be applied in different regions. In the following review, we present a whole range of indicators used to monitor different types of freshwater habitats, and discuss how some of these methods could be applied to temporary wetlands. Finally, we formulate some recommendations for temporary wetland monitoring and conservation.     

Dragonfly Assemblages in Arid Tropical Environments: A Case Study from Western Namibia

Dragonflies have been proposed as indicators for the ecosystem health of freshwater wetlands. For their useful functioning as indicators it is, however, necessary to identify species compositions in specific habitats and species-habitat associations, particularly in the tropics, where such knowledge is still weak. We examined the dragonfly species composition of 133 localities in the arid environment of western Namibia. An analysis of nestedness indicated that distinct, and predictable patterns of species associations can be expected. Discriminant analyses revealed that most of the nine habitat types separated by structural and hydrological parameters are well discriminated by their dragonfly assemblages. Spring brooks in particular host a specific assemblage, which is threatened due to the habitat restriction of several species, as well as by recent habitat loss and degradation. Using a hierarchical method of several criteria we demonstrated the selection of a set of potential indicator species from the species set, most of these being useful indicators for spring brook assemblages. The conservation status of certain habitats and species is discussed. We propose that dragonflies will have a high indicator potential for threatened freshwater wetlands in such areas and may also serve as an indication of the sustainable use of water resources including evaluating measures to rehabilitate environments.     

The influence of urban land use on seed dispersal and wetland invasibility

Urban habitats are generally considered highly invaded by exotic species due to the frequency and extent of disturbance caused by human activities and development. Our previous study had demonstrated that forested wetlands within residential areas are more extensively invaded than wetlands within industrial–commercial areas. In this study, we investigate whether the structure of the forest edge and seed dispersal can explain the differential in the invasion of wetlands surrounded by industrial and residential land use. Our results indicate that edges of industrially bordered wetlands are denser, with vegetation concentrated at the boundary of tree growth, whereas the edges of residentially bordered wetlands are more open and diffuse. This difference influences the number of seeds and species capable of dispersing into the wetland. Less dense edges resulted in a higher number of seeds entering residential wetlands; however, there were no differences in the numbers of exotic seeds or exotic species in the seed rain residential and industrial wetlands. Although seed dispersal could not directly explain differences in the current extent of invasion of these sites, seed dispersal did follow corridor pathways, including ditches and trails that breach the edges and extend through the wetlands. These disturbances act as corridors for seed dispersal into both types wetlands and may play a role in introducing new species to the interior of the wetland, an outcome supported by a higher number of exotic species in the seed banks of residential sites. Our results suggest that both the type of adjoining land use and the provision of access to people on trails in urban wetlands can affect the composition of these communities.     

Long-term monitoring of wetlands along the Western-Greek Bird Migration Route using Landsat and ASTER satellite images: Amvrakikos Gulf (Greece)

The west coast of Greece is an important migration route for migratory waterbirds. The wetlands along this coast are important stopover sites during bird migration between wintering and breeding sites. The use of remote sensing methods for mapping bird migration habitats and for temporal monitoring of changes in these habitats was investigated. The Amvrakikos Gulf, a coastal wetland complex along the west coast of Greece, was selected as the study area. Landsat TM and ETM+ images and ASTER VNIR images were used to perform a post-classification change detection over a time period of 15 years (1989–2004). In order to assess the spatial quality of existing wetland patches, spatial metrics (such as patch area, distance between the patches, and proximity) were calculated. To study changes in the degree of fragmentation of the stopover area, a binary patch structure was used in which the focal patches were embedded in a neutral matrix. The results showed that Landsat and ASTER VNIR satellite images can be used to trace small wetlands of approximately 0.5 ha minimum. These data sources are suitable for monitoring changes in wetlands, in particular marshes and mudflats, which are important habitats for migratory waterbirds. In the 15-year period that has been studied there was an estimated 32% decrease in marsh and mudflat area. Among this decrease, 25% went to water surface and 7% to vegetation in the months of August and September. Within the same period of time, a higher degree of fragmentation of the potential bird migration habitat has also been recorded. For this purpose, the remote sensing approach used in this study where change detection is performed on freely available Landsat and ASTER satellite images could be an interesting tool for policy makers and managers, as they allow easy recognition and monitoring of changes in wetlands and therefore contribute to an evaluation of the efficiency of protection and management schemes applied by countries for their wetlands.     

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.     

Temporal and spatial habitat preferences and biotic interactions between mosquito larvae and antagonistic crustaceans in the field

Investigations on natural antagonists of mosquito larvae found that micro‐crustaceans (e.g., Cladocera) control mosquito populations under experimental conditions. However, their relevance for mosquito control under field situations remains widely unclear because important information about habitat preferences and time of occurrence of crustaceans and mosquito larvae are still missing. In order to fill this knowledge gap, a field study was undertaken in different wetland areas of Saxony, Germany, in different habitats (i.e., grassland, forest, and reed‐covered wetlands). We found negative interactions between larvae of Ae. vexans and predatory Cyclopoida (Crustacean: Copepoda), which both were dominant during the first two weeks of hydroperiod, at ponds located at grassland habitats. Larvae of Cx. pipiens were spatially associated with competing Cladocera, but they colonized ponds more rapidly. Populations of Cladocera established from the third week of hydroperiod and prevented Cx. pipiens colonization thereafter. Ostracoda were highly abundant during the whole hydroperiod, but their presence was restricted to habitats of reed‐covered wetland at one geographical area. Mosquito larvae hardly occurred at those ponds. In general, we found that ponds at the reed‐covered wetlands provided better conditions for the initial development of crustaceans and hence, mosquito larval colonization was strongly inhibited. Grassland habitat, in contrast, favored early development of mosquito larvae. This study showed that micro‐crustaceans are relevant for mosquito management but their impact on mosquito larvae varies between species and depends on environmental conditions.     

Integrating multidirectional connectivity requirements in systematic conservation planning for freshwater systems

Aim Recent efforts to apply the principles of systematic conservation planning to freshwater ecosystems have focused on the special connected nature of these systems as a way to ensure adequacy (long‐term maintenance of biodiversity). Connectivity is important in maintaining biodiversity and key ecological processes in freshwater environments and is of special relevance for conservation planning in these systems. However, freshwater conservation planning has focused on longitudinal connectivity requirements within riverine ecosystems, while other habitats, such as floodplain wetlands or lakes and connections among them, have been overlooked. Here, we address this gap by incorporating a new component of connectivity in addition to the traditional longitudinal measure. Location Northern Australia. Methods We integrate lateral connections between freshwater areas (e.g. lakes and wetlands) that are not directly connected by the river network and the longitudinal upstream–downstream connections. We demonstrate how this can be used to incorporate ecological requirements of some water‐dependent taxa that can move across drainage divides, such as waterbirds. Results When applied together, the different connectivity rules allow the identification of priority areas that contain whole lakes or wetlands, their closest neighbours whenever possible, and the upstream/downstream reaches of rivers that flow into or from them. This would facilitate longitudinal and lateral movements of biota while minimizing the influence of disturbances potentially received from upstream or downstream reaches. Main conclusions This new approach to defining and applying different connectivity rules can help improve the adequacy of freshwater‐protected areas by enhancing movements of biodiversity within priority areas. The integration of multiple connectivity needs can also serve as a bridge to integrate freshwater and terrestrial conservation planning.     

The Evolving Role of Botanical Gardens and Natural Areas:A Floristic Case Study from Royal Botanical Gardens,Canada

As leaders calling for the conservation of the world’s plants,botanical gardens protect plants within living collections.Many also study,manage and restore plants in natural habitats.Royal Botanical Gardens(Ontario,Canada) has integrated both horticultural and natural heritage in its mission for decades.Envisioned by municipal leaders in the 1920s as a combination of nature sanctuaries and civic gardens,RBG now includes forests,wetlands and other habitats,gardens and built spaces.Today RBG is Canada’s largest botanical garden on the basis of area.In the 1950s RBG began to inventory plant diversity.The checklist of spontaneous vascular plants now exceeds 1 170 species,of which 752 are native.This is 37% of Ontario’s native vascular plants and 19% of the native vascular flora of Canada.The RBG nature sanctuaries are among the richest locations in Canada for species-level diversity.We examine the history of floristic exploration within RBG and compare plant species-area relationships among protected natural areas in Ontario.This comparison supports the contention that the nature sanctuaries,and in particular Cootes Paradise,could be considered an important area for plants in Canada,and relative to the nation’s flora,a biodiversity hotspot.The fact that a candidate vascular plant hotspot for Canada lies within a major botanical garden presents opportunities for raising public awareness of the importance of plant diversity,as well as focusing attention on the scientific and conservation biology needs of communities and individual species in this area.     

The Evolving Role of Botanical Gardens and Natural Areas: A Floristic Case Study from Royal Botanical Gardens, Canada

As leaders calling for the conservation of the world's plants, botanical gardens protect plants within living collections. Many also study, manage and restore plants in natural habitats. Royal Botanical Gardens (Ontario,Canada) has integrated both horticultural and natural heritage in its mission for decades. Envisioned by municipal leaders in the 1920s as a combination of nature sanctuaries and civic gardens, RBG now includes forests, wetlands and other habitats, gardens and built spaces. Today RBG is Canada's largest botanical garden on the basis of area.In the 1950s RBG began to inventory plant diversity. The checklist of spontaneous vascular plants now exceeds 1 170 species, of which 752 are native. This is 37% of Ontario's native vascular plants and 19% of the native vascular flora of Canada. The RBG nature sanctuaries are among the richest locations in Canada for species-level diversity.We examine the history of fioristic exploration within RBG and compare plant species-area relationships among protected natural areas in Ontario. This comparison supports the contention that the nature sanctuaries, and in particular Cootes Paradise, could be considered an important area for plants in Canada, and relative to the nation's flora, a biodiversity hotspot. The fact that a candidate vascular plant hotspot for Canada lies within a major botanical garden presents opportunities for raising public awareness of the importance of plant diversity, as well as focusing attention on the scientific and conservation biology needs of communities and individual species in this area.     

Microhabitat Association of Blanding's Turtles in Natural and Constructed Wetlands in Southeastern New York

ABSTRACT We studied Blanding's turtle (Emydoidea blandingii) microhabitat in natural wetlands and wetlands constructed for the turtles in Dutchess County, New York, USA. Investigation of these topics can provide information on ways to increase the extent of Blanding's turtle habitat, improve its quality, and assure that conservation or restoration managers do not overlook key habitat characteristics. Microhabitat was determined by radiotracking individuals to their exact locations and recording habitat variables. Blanding's turtles were associated with shallow water depths (x̄ = 30 cm), muck substrates, and areas of abundant vegetation (total cover xM = 87%). Buttonbush (Cephalanthus occidentalis)had the greatest mean total cover (29%). In the constructed wetlands, Blanding's turtles were associated with significantly less cover and warmer water than in the natural wetlands. Blanding's turtles appeared to be using the constructed wetlands to bask and forage in the spring and early summer but moved to deeper wetlands in late summer when the constructed wetlands dried up or became too warm. For Blanding's turtles, new habitat should contain abundant emergent vegetation (including buttonbush in Dutchess County and other areas where the turtles are known to use buttonbush swamps), basking areas, muck, floating plant material, and submerged aquatic vegetation. Blanding's turtle's use of constructed wetlands highlights the value of a complex of connected wetland habitats in providing for the varied needs of the turtle.     

Should ‘wetlands’ cover all aquatic ecosystems and do macrophytes make a difference to their ecosystem services?

The Ramsar Convention has gradually expanded the scope of the term ‘wetland’ to bring under its umbrella all kinds of inland freshwater (and saline) ecosystems as well as many marine ecosystems. It is not possible to develop a common framework for the study, management or policy of such a large and divergent assemblage of habitats with water being a single shared feature. In this paper, I argue that wetlands are distinct from deep open water systems such as rivers, lakes and reservoirs. The restriction of macrophytes (except the free floating plants like salvinia and water hyacinth) to shallow water habitats helps distinguish between wetlands and deep water systems. Following an ecosystem service approach, I discuss that wetlands are generally characterized by the occurrence of macrophytes, which critically contribute to their provisioning, regulating, supporting and cultural ecosystem services that differ significantly from those of the microphyte (phytoplankton)-dominated deep water habitats. I argue that wetlands do lie adjacent to deep and open water systems (including large rivers), which interact with them regularly and influence their biodiversity, hydrology, water quality and functioning, depending upon their relative areal extent and characteristics of the macrophyte community, but that only the littoral zones between the mean highest and lowest water levels (and stream banks and the floodplains beyond them in the case of rivers) should be treated as wetlands. Shallow lakes devoid of macrophytes because of eutrophication are degraded wetlands that need to be restored.     

Colonization of a newly constructed urban wetland by mosquitoes in England: implications for nuisance and vector species

Urban wetlands are being created in the UK as part of sustainable urban drainage strategies, to create wetland habitats lost during development, to provide a habitat for protected species, and to increase the public's access to ‘blue‐space’ for the improvement of health and well‐being. Sewage treatment reedbeds are also being incorporated into newly constructed wetlands to offer an alternative approach to dealing with sewage. This field study aims to provide the first UK evidence of how such newly constructed aquatic habitats are colonized by mosquitoes. A number of new aquatic habitats were surveyed for immature mosquitoes every fortnight over the first two years following wetland construction. The majority of mosquitoes collected were Culex sp. and were significantly associated with the sewage treatment reedbed system, particularly following storm events and sewage inflow. Other more natural aquatic habitats that were subject to cycles of drying and re‐wetting contributed the majority of the remaining mosquitoes colonizing. Colonization of permanent habitats was slow, particularly where fluctuations in water levels inhibited emergent vegetation growth. It is recommended that during the planning process for newly constructed wetlands consideration is given on a case‐by‐case basis to the impact of mosquitoes, either as a cause of nuisance or as potential vectors. Although ornithophagic Culex dominated in this wetland, their potential role as enzootic West Nile virus vectors should not be overlooked.     

Reasons for the loss and degradation of Australian wetlands

Wetland conservation and management in Australia is not supported by a comprehensive information base. A national inventory has not been compiled and we have very little information on the areal extent and loss of wetlands. Further, we have little information on the values and benefits (products, functions and attributes) derived from wetlands and how these have been degraded or lost. We do know, however, that in some areas at least, wetland loss and degradation has been severe and may even be still occurring. Much of the scientific attention to wetland management has been directed towards the apparent (or ecological) reasons for wetland loss and degradation – changes to the water regime, physical modification of the habitat, eutrophication and other pollution, and invasion by exotic pest species. Lists of threats to wetlands have been compiled, but these rarely address the non-ecological reasons that have resulted in so many wetlands being lost or degraded. In this paper we summarize the key points made from a number of case studies of Australian wetlands that highlight the non-ecological causes of wetland loss and degradation. From this analysis we conclude that awareness and understanding about the non-ecological causes of wetland loss and degradation need to be as well understood as the ecological causes. Foremost amongst these we highlight greater attention to the following issues: economic development in wetlands, bureaucratic obstacles, lack of information or poor access to information, and poor general awareness of the values and benefits derived from wetlands. We further conclude that wetland loss and degradation does not need to happen – our wetlands are valuable and already severely degraded. For this situation to be rectified we need to ensure that the knowledge and expertise of wetland scientists is heard and heeded by decision-makers and wetland users and owners.     

The role of wetland policies in the conservation of waterbirds: the case of Uganda

Mafabi, P. 2000. The role of wetland policies in the conservation of waterbirds: the case of Uganda. Ostrich 71 (1 & 2): 96–98.

Wetlands in Uganda provide important habitats for birds including several endemic species. With the ever increasing pressure to convert wetlands to agricultural lands, several species have lost their habitats, while others have become pests due to their opportunistic behaviour in modified habitats. The causes of wetland drainage and conversion in Uganda include population growth, economic reforms and a severe lack of information, legislation and inter-sectoral co-ordination. Community uses of wetlands have clear impacts on waterbirds. At Busolwe (case study 1) there is competition for land-use between Crowned Crane Balearica regulorum and man. Priority community uses of wetlands include fish-farming, agro-forestry and bee-keeping. There is a need for integrating bird conservation into overall wetland conservation objectives, especially with the aim of maintaining conditions suitable for waterbird survival during critical stages of the life-cycle. National wetland policies can play an important role in the conservation of waterbirds, as learned from Uganda's experiences. Recommendations for integrating bird conservation into the national wetland policy framework (as well as into national, district and local level planning processes) are made, which point to close co-operation between stakeholders for better management and on improved appreciation of wetlands values.     

疏浚泥用于滨海湿地生态工程现状及在我国应用潜力

疏浚泥传统的海上倾倒方式现已成为海洋的主要污染来源,而将疏浚泥应用到滨海湿地生态工程具有重要的价值和意义。疏浚泥应用于滨海湿地生态工程在国外的系统研究超过40a,工程运用已有上百年的历史。综述了海洋疏浚泥运用于滨海湿地生态工程的研究前沿和工程运用现状,同时分析其典型的生态工程案例,以期为我国的技术推广提供参考。疏浚泥用于生态工程用途主要有:(1)生态保育下沉和侵蚀性海岸湿地:人为补给疏浚泥可以补偿因高程降低或者海岸侵蚀带来的负面影响,国际上通常采用疏浚泥薄层覆盖法。(2)生态修复受损的滨海湿地:疏浚泥作为基质恢复和重建其潮间带生境,修复因围垦等人类活动严重受损的湿地,从而恢复湿地植被群落;(3)建造人工生态岛:将疏浚泥堆置于便利处,形成自然疏浚泥岛,按照不同的设计高程创造出不同的生境,随着自然的演替,岛屿演替成为生物多样性高和生境丰富的岛屿。以国际上的疏浚泥生态工程运用为借鉴,结合目前我国海洋经济发展的现状和滨海湿地面临的一系列挑战,分析疏浚泥在我国滨海湿地生态重建和生态修复等工程方面的应用前景,为缓解我国海洋产业经济发展和滨海湿地生态环境保护之间的矛盾提供技术借鉴。     

The classification of wetlands: integration of top-down and bottom-up approaches and their significance for ecosystem service determination

The typology of wetlands provides important information for both water resource managers and conservation planners. One of the most important aims of allocating wetlands to a certain type or class is to provide information about the ecosystem services that the wetland provides. There are two main approaches towards wetland classification. Firstly, there are top-down approaches whereby wetlands are divided into several categories based on a conceptual understanding of how the wetland functions (mostly with regards to water flows). Secondly there are bottom-up approaches whereby the classification of wetlands is based on the collection of data in the wetland that is then subjected to various clustering techniques (mostly with regards to biodiversity). The most utilized system of top-down classification assigns wetlands into hydrogeomorphic units, which function as a single unit in terms of hydrology and geomorphology. This type of classification is most useful for water resource planning, as it provides information about how the wetland is connected to the drainage network and what are the water inflows, throughflows and outflows of the wetland. The bottom-up classification approach typically focusses on the classification of wetland habitats rather than complete wetlands, where wetland habitat represents a spatial unit delineated on the basis of vegetation, embedded within the (complete) hydrogeomorphic unit, and defined as an area of wetland that is homogeneous in terms of opportunities for plant growth. At a broad scale, most ecosystem services can be superficially derived from the hydrogeomorphic unit type and the way water moves through a wetland, but habitat units and the plant species that define them would have a specific effect on the delivery of ecosystem services, for example, with different assemblages providing different resistance to flow. Some types of ecosystem services are exclusively linked to specific wetland habitats, especially provisioning services. For this reason, it is proposed that a combined approach of hydrogeomorphic classification together with a vegetation map, offers the maximum information value for ecosystem service determination. In order to account for the potential pitfall of “double counting” when combining the top-down and bottom-up approaches, each service needs to be considered individually with reference to the degree to which a service is either: (a) primarily determined by HGM class/attributes and modified by the vegetation class/attributes; or (b) primarily determined by the vegetation class/attributes.     

Evaluating regional resiliency of coastal wetlands to sea level rise through hypsometry‐based modeling

Sea level rise (SLR) threatens coastal wetlands worldwide, yet the fate of individual wetlands will vary based on local topography, wetland morphology, sediment dynamics, hydrologic processes, and plant‐mediated feedbacks. Local variability in these factors makes it difficult to predict SLR effects across wetlands or to develop a holistic regional perspective on SLR response for a diversity of wetland types. To improve regional predictions of SLR impacts to coastal wetlands, we developed a model that addresses the scale‐dependent factors controlling SLR response and accommodates different levels of data availability. The model quantifies SLR‐driven habitat conversion within wetlands across a region by predicting changes in individual wetland hypsometry. This standardized approach can be applied to all wetlands in a region regardless of data availability, making it ideal for modeling SLR response across a range of scales. Our model was applied to 105 wetlands in southern California that spanned a broad range of typology and data availability. Our findings suggest that if wetlands are confined to their current extents, the region will lose 12% of marsh habitats (vegetated marsh and unvegetated flats) with 0.6 m of SLR (projected for 2050) and 48% with 1.7 m of SLR (projected for 2100). Habitat conversion was more drastic in wetlands with larger proportions of marsh habitats relative to subtidal habitats and occurred more rapidly in small lagoons relative to larger sites. Our assessment can inform management of coastal wetland vulnerability, improve understanding of the SLR drivers relevant to individual wetlands, and highlight significant data gaps that impede SLR response modeling across spatial scales. This approach augments regional SLR assessments by considering spatial variability in SLR response drivers, addressing data gaps, and accommodating wetland diversity, which will provide greater insights into regional SLR response that are relevant to coastal management and restoration efforts.