Nitrogen, Phosphorus, Carbon, and Suspended Solids Loads from Forest Clear-Cutting and Site Preparation: Long-Term Paired Catchment Studies from Eastern Finland

• Published in: Ambio Vol. 43; no. 2; pp. 218 - 233
• Main Authors: Palviainen, Marjo, Finér, Leena, Laurén, Ari, Launiainen, Samuli, Piirainen, Sirpa, Mattsson, Tuija, Starr, Mike
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.03.2014; Springer; Springer Netherlands; Springer Nature B.V
• Subjects: Agricultural site preparation; Ammonium; Annual runoff; Atmospheric Sciences; Biological and medical sciences; Boreal forests; Carbon; Carbon - analysis; Catchment areas; Clearcutting; Earth and Environmental Science; Ecology; Environment; Environmental Engineering/Biotechnology; Environmental Management; Exports; Finland; Forest hydrology; Forest management; Forest practices; Forest soils; Forestry; Forestry research; forests; Fundamental and applied biological sciences. Psychology; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Lawns; long term effects; Mineralization; Nitrates; Nitrogen; Nitrogen - analysis; nitrogen content; Organic carbon; Organic nitrogen; Organic phosphorus; Peatlands; Phosphorus; Phosphorus - analysis; Physical Geography; Runoff; site preparation; Stream water; Surface runoff; Surface water; Suspended solids; Timber industry; Trees; Vegetation; Water - analysis; Water Pollution - analysis; Water quality; Watersheds; Finland; Scandinavia; Europe; Final cutting; Catchment; Leaching; Water quality; Soil preparation; Load; Forests; Phosphorus; Nitrogen; Long term; Suspended materials; Soils; Clearcutting; Watershed
• ISSN: 0044-7447; 1654-7209
• DOI: 10.1007/s13280-013-0439-x

The long-term impacts of current forest management methods on surface water quality in Fennoscandia are largely unexplored. We studied the long-term effects of clear-cutting and site preparation on runoff and the export of total nitrogen (total N), total organic nitrogen (TON), ammonium (NH₄-N), nitrate (NO₃-N), total phosphorus (total P), phosphate (PO₄-P), total organic carbon, and suspended solids (SS) in three paired-catchments in Eastern Finland. Clear-cutting and soil preparation were carried out on 34 % (C34), 11 % (C11), and 8 % (C8) of the area of the treated catchments and wide buffer zones were left along the streams. Clear-cutting and soil preparation increased annual runoff and total N, TON, NO₃-N, PO₄-P, and SS loads, except for SS, only in C34. Runoff increased by 16 % and the annual exports of total N, TON, NO₃-N, and PO₄-P by 18, 12, 270, and 12 %, respectively, during the 14-year period after clear-cutting. SS export increased by 291 % in C34, 134 % in C11, and 16 % in C8 during the 14, 6, and 11-year periods after clear-cutting. In the C11 catchment, NO₃-N export decreased by 12 %. The results indicate that while current forest management practices can increase the export of N, P and SS from boreal catchments for many years (>10 years), the increases are only significant when the area of clear cutting exceeds 30 % of catchment area.