Soil quality numerical valorisation - a tool in forest site diagnosis

Abstract

The numerical valorisation of soil quality is based on the determination of a set of soil properties adjusted to a given soil function in the ecosystem. The obtaining of an index is based on: determination of soil properties, their conversion into abstract numbers called indicators, index calculation and its practical application. The first proposal of a forest soil quality index was the Forest Soil Trophism Index - ITGL calculated for the soils presented in the Atlas of forest soils in Poland. The calculation of the ITGL, was based on the following soil properties: percentage share of very fine sand and coarse silt fraction (circle divide 0.1-0.02 mm) and silt and clay particles (circle divide <0.02mm), reaction, sum of exchangeable bases and organic matter decomposition degree, content of skeletal parts. Its variability in the forest soils of Poland oscillates between 6.0 and 43.0 and its application in the valorisation of forest sites is multidirectional.