Browsing by Subject "urban wetlands"

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  • Vehkaoja, Mia; Niemi, Milla; Vaananen, Veli-Matti (2020)
    Wetlands are one of the world's most important, economically valuable, and diverse ecosystems. A major proportion of wetland biodiversity is composed of aquatic invertebrates, which are essential for secondary production in aquatic and terrestrial food webs. Urban areas have intensified the challenges wetlands encounter by increasing the area of impermeable surfaces and the levels of nutrient and pollutant overflows. We investigated how urban infrastructure affects the aquatic invertebrate fauna of urban wetlands in metropolitan Helsinki, southern Finland. We measured riparian canopy cover, emergent vegetation coverage, and various land cover and road variables. Recreation area, forests, and open natural areas were the most important landscape features positively influencing aquatic invertebrate family richness, whereas buildings and roads had a negative effect on family richness and abundances of many taxa. Recreation area and the various forest types also positively affected the alpha-diversity indices of wetlands. On the other hand, fish assemblage did not affect either family richness or abundances of the studied taxa. Furthermore, trees growing on the shoreline negatively affected the diversity of aquatic invertebrate families. Invertebrate family diversity was greatest at well-connected wetlands, as these areas added to the regional species pool by over 33%. Our results show that connectivity and green areas near wetlands increase aquatic invertebrate family diversity, and our results could be utilized in urban planning. Graphical abstract
  • Liao, Wenfei (University of Helsinki, Ecosystems and Environment Research Programme, 2017)
    The Jakomäki-Vaarala wetland group and the Fazerila pond were studied in the summer 2017. The Fazerilanplotti had the most diverse invertebrate fauna (Table 3), while the Sydänlampi had the most diverse vertebrate fauna (Table 2). The smooth newts were found in the Twin-Länsi, Twin-Itä, and the Fazerilanplotti (Table 2). The biodiversity value of the Fazerilanplotti should be protected. The Jakomäki-Vaarala wetlands can be developed in different directions. The Vaaralanlampi and probably also the Sydänlampi can be developed for recreation, while the Twin ponds developed for their biodiversity values.
  • Hatakka, Tapio (Helsingin yliopisto, 2020)
    In the last few decades urbanisation has increased in Finland. Due to need for additional housing, it is necessary to compact current residential areas or develop existing green spaces into residential areas. Compact residential areas reduce water-permeable land cover and therefore increase stormwater runoff. Wetlands are increasingly being used for urban stormwater treatment as they are natural stormwater filtration systems. To assess utility of wetlands and streams it is important to identify their ecosystem services and ensuing benefits. Economic valuation methods can be applied to the valuation of small-water bodies and wetlands using either actual market information or a hypothetical market context created in a survey questionnaire. The aim of the research is to estimate the value of current and future ecosystem services provided by streams and wetlands in the drainage basin of Viikki residential area in Helsinki. The stated preferences survey was implemented to elicit resident’s benefits from wetland ecosystem services. The payment vehicle in a choice experiment was a yearly stormwater fee. This research focused on the wetlands and streams located in Viikki and the northern region of Vanhankaupunginlahti bay. Survey invitation was sent in 2016 to 1000 randomly selected residents in Viikki and nearby areas. The sample targeted the residents aged 19-79, and the shares of postal code areas were Viikki 21,6%, Myllypuro 24,4 % and Kontula-Vesala 54 % as the largest. The survey was responded partially or completely by 244 respondents. The willingness to pay for wetland ecosystem services was the highest for stormwater treatment, followed by recreational services and biodiversity. The information on wetlands did not affect the choices. Distance to wetlands and streams had negative effect on choice situations. A wealth of information and opinions were obtained from respondents about wetland ecosystem services and wetlands. Urban Oases-project have succeeded in providing wetland information to residents and in involving residents in environmental management. The feedback from the survey was essentially positive. Based on analysis, new urban wetlands projects would increase residential welfare.