Humus conditions and stand characteristics of artificially established young stands in the process of the transformation of spruce monocultures

Abstract

The main reason for the transformation of spruce monocultures at sites of mixed broadleaved forests is to create more natural relationships between the species structure of a stand and soil processes. The presented study compares humus conditions and basic growth characteristics of two mixed stands (spruce with beech and larch with beech) aged 25 years with a beech stand (aged 40 years) and spruce stand (aged 30 years). The purpose of the study is to evaluate (<I>i</I>) forms of forest floor, (<I>ii</I>) soil reaction, (<I>iii</I>) the content and total reserves of carbon, nitrogen and C/N ratio, (<I>iv</I>) dissolved organic carbon (DOC) in relation to stand characteristics. The highest reserve of forest floor is detected in the mixed stand of larch with beech (52.6 t/ha), the lowest reserve in a beech stand (21.0 t/ha). The soil reaction of the spruce stand and the beech stand is 4.0 (± 0.3) and 5.1 (± 0.3), respectively. The C/N ratio of the spruce stand is 23.5 (± 1.8) and that of the beech stand 18.8 ± 2.9. The DOC content decreases with layers of surface humus towards depth. Mixed stands represent by their values of soil conditions a mean between spruce and beech stands.