Stiftelsen Oscar och Lili Lamms Minne
Du är här: Hem // 2019 
TitelEco-friendly constructed mini wetlands for nutrient retention and plant diversity (ECO-wetlands)
NoFO2019-0012
UniversitetSwedish University of Agricultural Sciences
InstitutionDepartment of Aquatic Sciences and Assessment
HuvudsökandeMaidul I. Choudhury
Beviljat belopp1 010 900
Sammanfattning
Eutrophication in aquatic ecosystems is a global environmental issue, with a high socio-economic costs and biodiversity loss. Nitrogen (N) input from agricultural activities is one of the main reasons for eutrophication in freshwater and coastal ecosystems. In order to achieve sustainable agricultural practice and reduce eutrophication, it is crucial to retain nutrients in agricultural landscapes. Constructed wetlands along with different variants, e.g. constructed floating wetlands (CFWs), are now used to retain nutrients from agricultural activities. However, large scale in situ application of CFWs for N removal is not well studied and lacks use of environment friendly construction materials. We propose application of constructed mini wetlands (CMWs), a type of CFWs made of eco-friendly materials for N removal in constructed wetlands. The overall aims of the project ECO-wetlands are to evaluate in situ application of CMWs for a) improving N uptake and denitrification and overall nutrient retention in agricultural wetlands and, b) increasing wetland plant diversity by using CMWs. Thus, ECO-wetlands is relevant to the water conservation, one of the major focus of Oscar and Lili Lamms Memorial Foundation. CFWs consist of a buoyant mat, usually made of plastic materials e.g. PVC, floating in the water and planted with emergent aquatic plants (macrophytes) that develop extensive root systems in the water column. These root systems can provide a vast surface area and organic carbon for denitrifying bacterial growth and act as a hot spot for denitrification in the water column. As plants grow hydroponically in CFWs, they derive N directly from water. We propose using eco-friendly CMWs that can be made of wood chips packed in jute bags instead of plastic materials. The advantages of using wood chips are: 1) it's locally available, 2) wood chips can act as substrates for planting macrophytes in CMWs, 3) wood chips can provide organic carbon and surface area for denitrifying bacterial growth, 4) macrophyte species diversity can be manipulated in CMWs thus have potential to accelerate the plant succession and diversity in restored and newly created wetlands. Eco-wetlands will study a total of 20 agricultural wetlands in Kalmar county along with a mesocosm study in Linnaeus University, Kalmar. Länsstyrelsen Kalmar will act as a potential stakeholder in this project and taking active part in the planning to ensure results that the managers need for water conservation and wetland management. A previous study conducted with commercial CFWs in wetlands at LKAB mining sites in Kiruna, Sweden showed that CFWs planted with local macrophytes can have plant N accumulation and denitrification of 7.5-106.9 mg N/m2/day and 11.9-8446 mg N2O-N/m2/day, respectively depending on species. We expect higher N uptake and denitrification in ECO-wetland’s study area since the climatic conditions i.e. growing season and temperature is more suitable for plant growth and denitrification in southern Sweden compared to northern Sweden. Moreover, the construction materials that we proposed can have enhance effect on denitrification in constructed wetlands. The project Eco-wetland is suitable for 1-year post-doc research for main applicant.