Restored Wetlands in the Landscape: The influence of landcover on biochemical properties of restored wetlands in southern Sweden

Abstract

Restoring lost wetlands is an important step in recreating sensitive ecological systems, which also contributes to reduced greenhouse gas emissions, making it an important environmental and climate benefit. Although efforts to restore wetlands have been ongoing for some time, research on their properties in relation to the surrounding landscape is limited. This study examined 38 restored wetlands, half on peat and half on mineral soil, with the aim of understanding how land cover in the surrounding catchment area as well as a closer 1 km buffer might influence key biochemical properties as measured in situ in these wetlands. A random forest regression model was used to investigate whether a connection could be demonstrated between biochemical properties, catchment area and land cover characteristics. The result showed that for the catchment area of the wetlands, the model had an explanatory power of R2 = 0.865 for dissolved organic carbon (DOC) taken nearest the wetland intake and R2 = 0.897 for pH, indicating a strong relationship between these biochemical properties and the catchment area. For neighboring 1 km land cover of the wetlands, the random forest regression model had an R2 = 0.845 for DOC taken nearest the wetland intake. In these cases, the land cover type showing the highest influence on the DOC model was “Pine forest on wetland” and “Mixed forest on wetland”, respectively for the catchment and 1 km areas. On the pH model, the highest land cover type influence was “Arable land” for both catchment and 1 km area. The DOC 02 and pH parameters also demonstrated significant difference between restored wetlands on peat and mineral soil. Additionally, the “Pine forest on wetland” land cover showed the clearest distinction between peat and mineral soil.