Trends in concentration and load of total organic carbon in forested catchments in Finland

Sakari Sarkkola, Harri Koivusalo, Ari Laurén, Pirkko Kortelainen, Tuija Mattson, Sirpa Piirainen, Mike Starr and Leena Finér

After Wise Use – The Future of Peatlands, Proceedings of the 13th International Peat Congress: Chemical, Physical and Biological Characteristics of Peat

forested-catchment, organic-carbon, time-series, water-quality

Sarkkola et al. 2008: Trends in concentration and load of total organic carbon


Long-term trends in concentration and export of total organic carbon (TOC) were studied in forested headwater catchments within a climatically consistent area in eastern Finland. The material consists of 11 small catchments (29-494 ha), where the proportion of peatland ranged from 8 to 70%. Runoff and TOC concentration were intensively monitored for 15-29 years in each catchment. Seven catchments have been subject to forestry operations with various management intensities and four catchments have been left unmanaged. Significant increasing annual trends in TOC concentrations were found for seven of the catchments. Seasonal Kendall tests revealed the strongest upward trend in TOC concentrations and export occurred in wintertime.