The effects of different canopy covers on the herb layer in the forest-steppes of the Grazer Bergland (Eastern Alps, Austria)

Аннотация

The submontane belt of the eastern Alps is dominated by beech forests. However, on rocky and steep south-facing slopes, small vegetation mosaics have developed, which, to a certain degree, are similar to the Pannonian forest-steppes. In spite of their unique conservation importance and threatened status, they have received relatively little scientific attention. In this study we analyzed the spatial pattern of such mosaics. More specifically, our objective was to find out how canopy cover value influences the species composition of the herb layer. According to our results, canopy cover of Pinus sylvestris has a rather limited effect on the herb layer composition and species richness. Thus, in the studied canopy cover range (ca. 5–75% canopy cover), most species occurred under all canopy cover grades. This is presumably a result of the canopy characteristics and branching pattern of P. sylvestris: it can be assumed that the physical conditions of the canopy and intercanopy patches are somewhat similar. This is in sharp contrast with the Pannonian forest-steppes dominated by Quercus pubescens. We conclude that, even though the cessation of traditional land-use may not result in a rapid change of the composition in eastern Austrian forest-steppes, every effort must be made to conserve these valuable habitats.