Natural and Restored Wetland Buffers in Reducing Sediment and Nutrient Export from Forested Catchments: Finnish Experiences

Abstract

One of the water quality management practices in forested catchments is to construct wetland buffers between managed areas and recipient water courses. Wetland buffers can be constructed simply by routing runoff from forested areas to natural peatlands and wetlands, or by rewetting lower sections of drained peatlands by filling in or blocking the drainage ditches. The use of natural and restored wetland buffers for reducing nutrient and sediment export from forested catchments, particularly catchments dominated by forestry-drained peatlands, has been studied actively in Finland during the last 15 years. The studies have shown highly variable retention capacity for wetland buffers with different site characteristics and under different environmental conditions. In favorable conditions, high amounts of sediments and adhered mineral elements may be deposited within peat and surface vegetation of the buffer. Dissolved nutrients can be retained biologically into plant

Boreal peatland forests: ditch network maintenance effort and water protection in a forest rotation framework

“…Based on the average retention calculated by Väänänen et al (2008) and Silvan et al (2005), overland flow fields are assumed to retain approximately 77% of this dissolved inorganic phosphorus load. The remaining 23% of the dissolved phosphorus load from final felling is in organic form, and we assume that the overland flow fields are unable to retain it (Nieminen et al 2015).…”

“…The nutrient load from final felling consists of both nitrogen and phosphorus loads. The overland flow field is able to retain the nitrogen and phosphorus adhered to suspended sediments (particulate forms) and dissolved inorganic nitrogen and phosphorus loads, but it is assumed to be unable to retain significant amounts of dissolved organic nitrogen and phosphorus forms(Nieminen et al 2015). Here, in the theoretical model, we simplify and do not separate particulate and dissolved organic and inorganic forms of nitrogen and phosphorus.…”

Combining unmanned aerial vehicle-based remote sensing and stable water isotope analysis to monitor treatment peatlands of mining areas

“…Treatment peatlands are a type of constructed wetland (CW) established on pristine mires. Treatment peatlands are efficient in purifying different process effluents, including treated municipal wastewaters (Nichols, 1983;Ronkanen and Kløve, 2007), mining process waters (Humphries et al, 2016;Kwong et al, 1994), and runoff waters from peat extraction areas (Karjalainen et al, 2016), forestry (Nieminen et al, 2014;Silvan et al, 2004) and agricultural areas (Kleimeier et al, 2014). As peatlands are abundant, especially in the boreal climate zone, they can serve as a cost-efficient and low-maintenance method to treat large amounts of water, in order to reduce the environmental impact of point and diffuse pollutant sources on recipient water bodies (e.g., Gazea et al, 1996;Szucs, 2006).…”

Urban wetland parks in Finland: improving water quality and creating endangered habitats

“…While the Gateway wetland mean inundated area is only 0.1% of its 550 ha watershed area, and the monitored year 2013 only the fourth growing season since wetland excavation, an annual average of 10% for TP reduction was reached. In peatland forestry, long-restored peatland buffers between managed areas and recipient watercourses with the size of over 1% of the watershed area have been noted to be effective in SS and nutrient trapping (Nieminen et al 2014).…”