The impact of land use and land cover changes on soil properties and plant communities in the Gorce Mountains (Western Polish Carpathians), during the past 50 years

The research was carried out in the Jaszcze and Jamne catchments (area of 11.39 km(2) and 8.95 km(2), respectively) in the Gorce Mountains (the Western Polish Carpathians). Analysis of aerial photographs from the period 1954-2009 shows that land use and land cover changes in both catchments have intensified since the economic transformation of 1989. Changes in inhabitants' sources of income led to an increase in the area of forest (in the Jaszcze and Jamne catchments, by 14.6% and 24.0%, respectively) at the expense of agricultural land. Land use changes resulted in decreases in soil erosion. Reduced slope wash has limited the amount of suspended load, which in turn has resulted in the interruption of aggradation on their floodplains. The average bed incision has increased, from 0.24 cm per year and 0.32 cm per year, in the Jaszcze and Jamne streams, respectively, during the period 1964-1968, to 1 cm per year for the period 1969-2008. Such land use changes are not much in evidence in soils under arable and fallow land, in terms of organic carbon content, phosphorus content, or in the saturation level of the sorption complex. This may be an effect of the short time since the discontinuation of plowing (ten to thirty years). The differences between pH and nitrogen content of these soils are small and are not the result of present-day land use. Only the higher organic matter content in the soils under arable land is the result of continuous fertilization. In contrast, micromorphological analysis of thin sections shows distinct differences between arable land and fallow land. In soils under arable land, well-developed angular microstructure occurs. Here, plowing traces are easily visible. In soils under fallow land, massive or channel microstructure dominate. On the basis of a phytosociological map from the 1960's, resurveyed in 2012-2013, a clear decrease in segetal communities as well as poor grasslands was observed. These communities were mainly replaced by floristically impoverished dense thickets, plots dominated by Vaccinium myrtillus, and communities developed on fallow lands.