Controls of Organic Carbon and Nutrient Export from Unmanaged and Managed Boreal Forested Catchments

Understanding the anthropogenic and natural factors that affect runoff water quality is essential for proper planning of protection forest management, particularly in changing climate. We measured from 10 unmanaged 20 managed forested headwater catchments (7–12,149 ha) located Finland. used linear mixed effect models to test whether differences total organic carbon (TOC), nitrogen (TN) phosphorus (TP) export concentrations observed can be explained by catchment characteristics, land use, soil fertility, tree volume hydrometeorological variables. Results show much variation TOC, TN TP was drainage, temperature sum, peatland percentage proportion arable area catchment. These 45–63% exports. Mean annual TOC 56.4 ± 9.6 kg ha−1 a−1, while it 79.3 3.3 a−1. Same values were 1.43 0.2 a−1 2.31 0.053 0.009 0.095 0.008 managed, respectively. Corresponding were: 17.7 2.1 mg L−1 28.7 1.6 L−1, 420 45 µg 825 51 15.3 2.3 35.6 L−1. Overall exports significantly higher than catchments. Long term sum had an increasing on all exports, indicating climate warming may set new challenges controlling nutrient loads areas.