Replacing natural wetlands with stormwater management facilities: Biophysical and perceived social values

Quantifying intangible values of wetlands as instrument for conservation in the Po delta park (Italy)

Wetlands possess intangible values that are usually overlooked in decision-making processes. Based on questionnaire surveys, this work aims to quantify both the non-use and cultural values provided by the different wetlands of the Po Delta Park (Northern Italy), selected as ideal case study, using willingness to pay (WTP) for wetland conservation and travel cost methods, respectively. Their relationships with socio-economic variables and respondents' preferences for current and future use were also analysed. The 61.39% of participants were willing to pay a mean amount of 95.8 € (±40). The average travel cost was 38.68 € (±6.24), with higher values observed for environmental experts than for other citizens. Wetlands differ significantly in travel costs, current and future use, but not in WTP. Poisson regressions showed that non-use and cultural values were significantly dependent on personal information, preference variables and travel distance. Intangible dimensions, such as bequest and existence values, showed higher valuations/rates than option and direct use values. The results highlight that perceptions of the intrinsic value of nature are influenced by demographic characteristics, distance from the area and desired future uses. Non-use values seem abstract and generalised to the whole area, regardless of the ecological characteristics of the wetland, even though a significant relation to wetland uses was observed. In contrast, cultural values are tied to specific wetlands, as indication of the importance of historical relationships between people and nature. Such findings underline that the different dimensions of intrinsic value of nature may act at different scales and help decision-makers to incorporate such values into environmental accounting.

Urban-use pesticides in stormwater ponds and their accumulation in biofilms

Stormwater ponds frequently receive urban runoff, increasing the likelihood of pesticide contamination. Biofilms growing in surface waters of these ponds are known to accumulate a range of aquatic contaminants, paradoxically providing both water purification services and potentially posing a threat to urban wildlife. Thus, sampling biofilms in stormwater ponds may be a critical and biologically relevant tool for characterizing pesticide contamination and toxicity in urban environments. Here, we aimed to investigate pesticide occurrences at 21 stormwater ponds in Brampton, ON, one of Canada's fastest growing municipalities, and quantify their accumulation in biofilm. Over nine weeks, we collected time-integrated composite water and biofilm samples for analysis of ∼500 current-use and legacy pesticides. Thirty-two pesticide compounds were detected across both matrices, with 2,4-D, MCPA, MCPP, azoxystrobin, bentazon, triclopyr, and diuron having near-ubiquitous occurrences. Several compounds not typically monitored in pesticide suites (e.g., melamine and nicotine) were also detected, but only in biofilms. Overall, 56 % of analytes detected in biofilms were not found in water samples, indicating traditional pesticide monitoring practices fail to capture all exposure routes, as even when pesticides are below detection levels in water, organisms may still be exposed via dietary pathways. Calculated bioconcentration factors ranged from 4.2 to 1275 and were not predicted by standard pesticide physicochemical properties. Monitoring biofilms provides a sensitive and comprehensive supplement to water sampling for pesticide quantification in urban areas, and identifying pesticide occurrences in stormwater could improve source-tracking efforts in the future. Further research is needed to understand the mechanisms driving pesticide accumulation, to investigate toxicity risks associated with pesticide-contaminated biofilm, and to evaluate whether pesticide accumulation in stormwater pond biofilms represents a route through which contaminants are mobilized into the surrounding terrestrial and downstream aquatic environments.

Habitat complexity, connectivity, and introduced fish drive pond community structure along an urban to rural gradient

Urbanization can influence local richness (alpha diversity) and community composition (beta diversity) in numerous ways. For instance, reduced connectivity and land cover change may lead to the loss of native specialist taxa, decreasing alpha diversity. Alternatively, if urbanization facilitates nonnative species introductions and generalist taxa, alpha diversity may remain unchanged or increase, while beta diversity could decline due to the homogenization of community structure. Wetlands and ponds provide critical ecosystem services and support diverse communities, making them important systems in which to understand the consequences of urbanization. To determine how urban development shapes pond community structure, we surveyed 68 ponds around Madison, Wisconsin, USA, which were classified as urban, greenspace, or rural based on surrounding land use. We evaluated how landscape and local pond factors were correlated with the alpha diversity of aquatic plants, macroinvertebrates, and aquatic vertebrates. We also analyzed whether surrounding land use was associated with changes in community composition and the presence of specific taxa. We found a 23% decrease in mean richness (alpha diversity) from rural to urban pond sites and a 15% decrease from rural to greenspace pond sites. Among landscape factors, adjacent developed land, mowed lawn cover, and greater distances to other waterbodies were negatively correlated with observed pond richness. Among pond level factors, habitat complexity was associated with increased richness, while nonnative fishes were associated with decreased richness. Beta diversity was relatively high for all ponds due to turnover in composition between sites. Urban ponds supported more nonnative species, lacked a subset of native species found in rural ponds, and had slightly higher beta diversity than greenspace and rural ponds. Our results suggest that integrating ponds into connected greenspaces, maintaining riparian vegetation, preventing nonnative fish introductions, and promoting habitat complexity may mitigate the negative effects of urbanization on aquatic richness. While ponds are small in size and rarely incorporated into urban conservation planning, the high beta diversity of distinct pond communities emphasizes their importance for supporting urban biodiversity.

The integration of nature values and services in the nature-based solution assessment framework of constructed wetlands for carbon-water nexus in carbon sequestration and water security

As the climate change impacts are expected to become increasingly disruptive, affecting water security, environmental health and ecosystem, constructed wetlands receive attention for their functions in delivering various life-sustaining services to human and environmental systems. In this article, a systematic review was conducted through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard to identify the current research on constructed wetlands' nature values and services from 2011 to 2020 of two databases, namely Scopus and Web of Science. The criteria of assessment focus on holistic deliberation of subject matters, namely carbon sequestration and water security as regulating and provisioning services, as well as nature values of constructed wetlands, namely instrumental and intrinsic values. As a result, 38 articles were selected and comprehensively examined. As the lack of an interdisciplinary approach makes data and information integration difficult, this study derived an integrated classification of constructed wetlands' services and mapped with its nature values, guided by the Millennium Ecosystem Assessment framework. Besides, mechanisms and factors affecting carbon sequestration and water security were also discussed. The carbon-water nexus was then conceptualised as interlinkages between engineered and natural physicochemical processes at the interface between carbon and water cycles. To fill the gaps, based on the carbon-water nexus concept, a new framework was synthesised at the end of the deliberation for constructed wetlands in regulating local climate through carbon sequestration and ensuring water security through water treatment and purification as well as influencing socio-cultural values, which needs an integrated approach that is the novelty of this work. The framework integrates the dichotomy of the instrumental-intrinsic nature values of constructed wetlands to evaluate the importance and benefit of the carbon-water nexus. The framework that reveals the vitality of nature values provided by constructed wetlands can help improve the decision-making to prioritise ecosystem services and conservation efforts, particularly in the sustainable management of constructed wetlands.

Community experiences of landscape-based stormwater management practices: A review

Urban stormwater management increasingly changes urban landscapes. From rain gardens to stormwater ponds, landscape-based practices are visible and often accessible to community members, whose support and experience of these practices will affect their success. This critical narrative review addresses these Landscape-based Stormwater Management Practices (L-SWMPs). It assesses quantitative and qualitative evidence for the effects of characteristics of individual community members, L-SWMP landscape context, and L-SWMPs themselves on community members' perceptions, attitudes, and societal outcomes. Characteristics of community members are most well-studied. Environmental knowledge and past experiences of community members have strong, consistent effects, while the effects of demographic characteristics are weaker and inconsistent. Landscape characteristics, especially greenspace context and neighborhood landscape norms, consistently influence perceptions of L-SWMPs as amenities. Effects of noticeable L-SWMP characteristics are understudied; we argue that paying greater attention to these characteristics may help practitioners innovate L-SWMPs that benefit communities and receive their support.

Trends and predictors of wetland conversion in urbanizing environments

Wetlands provide critical ecosystem services including flood mitigation and habitat for diverse species, but globally, many wetlands have been destroyed. In urban areas and surrounding urban-rural fringes, many lost wetlands have been indirectly replaced with stormwater management (SWM) ponds. SWM ponds are designed to manage urban stormwater and contaminants, but only provide limited ecosystem services. In our study area, historic extent of wetland loss is partially documented, while more recent losses and SWM pond creation have not been fully reported. We examine wetland loss and SWM pond creation in seven southern Ontario (Canada) municipalities from 2002 to 2010. We then apply a Markov model to project future extent of wetland losses and SWM pond creation, with and without effects of specific land use and land cover types. We find that from 2002 to 2010, 95.5 ha of wetlands were lost, with most being smaller than 2 ha in size. A total area of 111.6 ha of SWM ponds was created, but on average, created SWM ponds were smaller than lost wetlands. Our projections to 2026 suggest wetland losses of 438.1 ha and SWM pond creation of 293.8 ha. We suggest a need for more stringent wetland protection policies to conserve wetlands that still exist in growing municipalities, especially smaller wetlands. Lack of such protection will weaken provisioning of wetland-related ecosystem services, which are more critical than ever in a changing climate.

Urban Wetlands: A Review on Ecological and Cultural Values

Wetlands are a critical part of natural environments that offer a wide range of ecosystem services. In urban areas, wetlands contribute to the livability of cities through improving the water quality, carbon sequestration, providing habitats for wildlife species, reducing the effects of urban heat islands, and creating recreation opportunities. However, maintaining wetlands in urban areas faces many challenges, such as the reduction of hydrological functions, changed water regimes due to barriers, contamination by wastewater, habitat loss due to land-use change, and loss of biodiversity due to the entry of alien species. In this article, we review the theoretical background of wetlands in urban areas through the existing studies in the literature. We provide knowledge on urban wetlands and highlight the benefits of these wetlands in urban areas. These benefits include sustainability, biodiversity, urban heat islands, social perception, and recreation values. We also summarize the objectives, methodologies, and findings of the reviewed articles in five tables. In addition, we summarize the critical research gaps addressed in the reviewed articles. Our review study addresses the research gaps by performing a rigorous analysis to identify significant open research challenges, showing the path toward future research in the field. We further discuss and highlight the role of policymakers and stakeholders in preserving wetlands and finally present our conclusions.

Functions of constructed wetland animals in water environment protection - A critical review

Constructed wetlands (CWLs) are widely used for water environment protection. In some cases, CWL animals can help improve CWL treatment efficiency and contribute to CWL maintenance and management. However, while plants, microorganisms, and substrates in CWLs have received much attention, animals have been largely ignored. Therefore, the aims of this review are to determine the roles wetland animals play in the water environmental protection of CWLs. This study introduced species of wetland animals and the main factors that can affect their survival. The way in which CWL animals affect pollutants was discussed in detail from four perspectives: adsorption and bioaccumulation, bioturbation, and the influence of CWL animals on plants and microorganisms. The characteristics of CWL animals that can be used for biological monitoring are summarized, and the use of CWLs for the protection of wetland biodiversity is also discussed. Finally, some prospects are proposed for future research. This study will help researchers better understand the role of CWL animals in CWLs and encourage researchers to focus on studies of wetland animals.

Contamination of Urban Stormwater Pond Sediments: A Study of 259 Legacy and Contemporary Organic Substances

Stormwater ponds improve water quality by facilitating the sedimentation of particles and particulate contaminants from urban runoff. Over time, this function entails the accumulation of contaminated sediments, which must be removed periodically to maintain a pond's hydraulic and treatment capacity. In this study, sediments from 17 stormwater sedimentation facilities from four Swedish municipalities were analyzed for 259 organic substances likely to be found in the urban environment. A total of 92 substances were detected in at least one sample, while as many as 52 substances were detected in a single sample. A typical profile of urban contamination was identified, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, organotins, aliphatic hydrocarbons, phthalates, aldehydes, polybrominated diphenyl ethers, perfluorinated substances, and alkylphenols. However, levels of contamination varied greatly between ponds, influenced heavily by the dilution of urban pollutants and wear particles from other sources of particles such as eroded soil, sand, or natural organic matter. For 22 of 32 samples, the observed concentrations of at least one organic substance exceeded the regulatory threshold values derived from toxicity data for both sediment and soil.

Factors influencing perceptions of aquatic ecosystems

While factors influencing perceptions of drinking water have been well studied, those of aquatic ecosystems have been to lesser extent. We conducted a review to improve awareness of these factors. Environmental factors found to influence public perceptions of aquatic ecosystems were presence/absence of water plants and algae, presence/absence of floating debris, the odor, movement (for flowing waters) and clarity/turbidity of the water, and the type, condition, setting, naturalness, and overall aesthetic appeal of the ecosystem. Sociocultural factors found to influence public perceptions of aquatic ecosystems included age, education, gender, and place-based knowledge. We provide perspectives of how managers can better meet the diverse social demands placed on aquatic ecosystems. The importance and benefits of considering these perspectives may be especially beneficial where significant multi-generational and culturally relevant place-based knowledge exist.

Identification of transformation products to characterize the ability of a natural wetland to degrade synthetic organic pollutants

Natural wetlands have been recognized as a natural reactor for degradation and elimination of environmental pollutants. The Upo Wetland, the largest inland wetland in Korea, is mainly surrounded by agricultural lands and it is susceptible to contamination from excess nutrient loads and synthetic organic contaminants (SOCs) (e.g., pesticides). The aim of this study was to identify major SOCs in the wetland and evaluate their degradation. We used high resolution mass spectrometry (HRMS) with a two-step analysis approach (i.e., 1^st analysis for target measurement along with suspect and non-target screening (SNTS) and 2^nd analysis for complimentary suspect screening) to identify and quantify the transformation products (TPs) of the identified parent SOCs. Quantitative analysis of 30 targets, mainly including pesticides, showed that fungicides were the major SOCs detected in the wetland, accounting for about 50% of the composition ratio of the total SOCs quantified. Orysastrobin occurred at the highest mean concentration (>700 ng/L), followed by two other fungicides, carbendazim and tricyclazole. The first analysis (SNTS) tentatively identified 39 TPs (30 by suspect, 9 by non-target screening) of 14 parent pesticides. Additionally, the second analysis (complimentary suspect screening) identified 9 more TPs. Among the 48 total TPs identified, 7 were confirmed with reference standards. The identification of the remaining TPs had a high confidence level (e.g., level 2 or 3). Regarding transport though the wetland, most TPs showed greater peak area ratios (i.e., the relative portion of chromatographic area of the TPs to the parent compound) at the outlet point of the wetland compared to the inlet point. The risk quotient, which was calculated using the concentrations of parent compounds, decreased toward the outlet, demonstrating the degradation capacity of the wetland. The estimates for biodegradability, hydrophobicity, and toxicity by an in-silico quantitative structure-activity relationship (QSAR) model indicated a lower half-life, lower logD_OW, and greater effect concentration for most TPs compared to the parent compounds. Based on these results, we conclude that natural wetlands play a role as an eco-friendly reactor for degrading SOCs to form numerous TPs that are lower risk than the parent compounds.

Perceived Quality of Urban Wetland Parks: A Second-Order Factor Structure Equation Modeling

Wetland in the urban or peri-urban areas has been recognized as an important component of urban ecosystems and provides ecological and environmental services. Wetland park emerged as a kind of restoration of natural wetlands in the context of increasing pressure on land and eco-environment caused by urban sprawl, which has played an essential role in providing recreational spaces/opportunities and improving social interactions. However, little research has been conducted on the theoretical formulation elaborating individuals’ perceived quality of wetland parks when people are engaging in activities therein. This study is an attempt to develop a method to measure the quality of wetland parks based on individuals’ various perceptions and attitudes. From the view of human-nature interaction, the perceived quality is hypothetically conceptualized as a composite of two dimensions, such as comfort perception and environmental satisfaction. A series of questionnaire-based surveys were conducted among respondents (N = 936) in Yanghu wetland park in Changsha, China. Based on the measured items from on-site surveys, second-order factor structural equation modeling is applied to estimate the hypothesis of a hierarchical structure for elaborating how the quality of wetland park is perceived by individual respondents. The results test the hypothesis that the quality of wetland park as a second-order theoretical construct can be conceptualized by two first-order theoretical constructs, individuals’ comfort (loading = 0.749), and environmental satisfaction (loading = 0.828). In addition, a significant influence of attitudes toward green space on the perceived quality of wetland park has been identified.

Knowledge, attitudes, intentions, and behavior related to green infrastructure for flood management: A systematic literature review

Green infrastructure (GI), which mimics natural hydrological systems, is a promising solution for flood management at the intersection of urban built infrastructure and natural systems. However, it has not yet achieved widespread uptake, due in part to insufficient understanding of human dimensions of the broader socio-ecological-technical system. We therefore conducted a multidisciplinary systematic literature review to synthesize research on people's existing knowledge about flood risk and GI, and how that shapes their attitudes and motivation to adopt new solutions. We systematically screened 21,207 studies on GI for flood management; 85 met our inclusion criteria. We qualitatively analyzed these studies to extract results on knowledge, attitudes, intentions, and behavior relating to GI for flood management. Overall, knowledge of GI was low across the 44 studies in which it was evaluated. Seventy studies assessed attitudes about GI, including the functional, aesthetic, health and safety, recreational, conservation, financial, and cultural value of GI, albeit their measurement was inconsistent. Willingness to implement or pay for GI varied considerably across 55 studies in which it was measured. Twenty studies measured and documented behavior relating to GI use, and these found low rates of adoption. Few studies systematically assessed the role of demographic, socio-economic, or geographic characteristics that could influence individuals' knowledge, attitudes, intentions or behavior, and thereby the success of GI programs. We recommend that researchers should more systematically capture data on human dimensions of GI (i.e. knowledge, attitudes, intentions, and behavior) across diverse settings to improve program design and uptake, especially among vulnerable populations. Greater attention to the social component of the socio-ecological-technical system will help ensure that GI programs are equitable, inclusive, and sustainable.

Factors influencing social demands of aquatic ecosystems

Aquatic ecosystems provide services essential to human health and economies. Therefore, resource management programs aim to ensure the sustainable flow of these services. Stakeholder engagement is often a critical tool in learning what services are of priority to the public and may be integral to the success of aquatic ecosystem management because public participation in planning and decision making can generate broader support, e.g., financial, intellectual, and labor, for the management plan. The collection of such information may even be statutorily mandated, such as in the Clean Water Act of the United States, which requires that water bodies be classified for the beneficial uses, e.g., fisheries, drinking water, or recreation, they provide. Past evaluations of stakeholder engagement with aquatic ecosystems have considered a wide range of factors influencing engagement. We conducted a critical review of the literature on characteristics of stakeholders and characteristics of the environment that influence stakeholder engagement and participation with aquatic ecosystems. Our objective was to identify factors that should be considered in the creation of surveys to help encourage the inclusion of ecological and social beneficial uses data in large-scale water monitoring programs. Factors identified in our review were, extent and influence of place-based knowledge; proximity to, and frequency of visitation of the resource(s) being considered; basic demographics such as age, gender, education, and income; home community type; aesthetic appeal of the resource; and primary reason for engagement with the resource. We propose these factors, with subfactors, as a template for survey development.