Vol14 No.12: 2391-2405
【Title】Labile and stabile soil organic carbon fractions in surface horizons of mountain soils – relationships with vegetation and altitude
【Author】BOJKO Oskar1*; KABALA Cezary1; MENDYK Łukasz2,4; MARKIEWICZ Maciej2; PAGACZ-KOSTRZEWA Magdalena3; GLINA Bartłomiej4
【Addresses】1 Institute of Soil Science and Environmental Protection, Wrocław University of Environmental and Life Sciences, Grunwaldzka 53, 50-357 Wrocław, Poland; 2 Department of Soil Science and Landscape Management, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; 3 Faculty of Chemistry, University of Wrocław, Joliot-Curie 14, 50-383 Wrocław, Poland; 4 Department of Soil Science and Land Protection, Poznań University of Life Science, Szydłowska 50, 60-656 Poznań, Poland
【Citation】Bojko O, Kabala C, Mendyk L, et al. (2017) Labile and stabile soil organic carbon fractions in surface horizons of mountain soils – relationships with vegetation and altitude. Journal of Mountain Science 14(12). https://doi.org/10.1007/s11629-017-4449-1
【Abstract】Global and local climate changes could disturb carbon sequestration and carbon stocks in forest soils. Thus, it is important to characterize the stability of soil organic matter and the dynamics of soil organic carbon (SOC) fractions in forest ecosystems. This study had two aims: (1) to evaluate the effects of altitude and vegetation on the content of labile and stabile forms of organic carbon in the mountain soils; and (2) to assess the impact of the properties of soil organic matter on the SOC pools under changing environmental conditions. The studies were conducted in the Karkonosze Mountains (SW Poland, Central Europe). The content of the most labile fraction of carbon (dissolved organic carbon, DOC) decreases with altitude, but the content of fulvic acids (FA), clearly increases in the zone above 1000 m asl, while the stabile fraction (humins, non-hydrolyzing carbon) significantly decreases. A higher contribution of stabile forms was found in soils under coniferous forests (Norway spruce), while a smaller - under deciduous forests (European beech) and on grasslands. The expected climate change and the ongoing land use transformations in the zone above 1000 m asl may lead to a substantial increase in the stable humus fraction (mainly of a non-hydrolyzing carbon) and an increase in the SOC pools, even if humus acids are characterized by a lower maturity and greater mobility favorable to soil podzolization. In the lower zone (below 1000 m asl), a decrease in the most stable humus forms can be expected, accompanied by an increase of DOC contribution,which will result in a reduction in SOC pools. Overall, the expected prevailing (spatial) effect is a decreasing contribution of the most stable humus fractions, which will be associated with a reduction in the SOC pools in medium-high mountains of temperate zone of Central Europe.
【Keywords】Soil organic matter; Humus fractions; Dissolved organic carbon; Organic carbon pools; Vegetation; Climate; Mountain soils