Veränderung der Durchwurzelungsverhältnisse beim Umbau von Kiefernforsten zu Buchenbeständen auf kräftigen Sandbraunerden

Abstract

The main objective of the study is to analyze, quantify and evaluate the effects of advanced planting of beech (Fagus syhatica L) on the rhizosphere of Scots pine forests (Pinus sylvestris L.) on sandy soils in NE-Germany. The study revealed that the total root biomass increased not inevitable with age but with the degree of naturalness of the forests resp. with the ratio of introduced beech trees. In pure stands beech shows the highest rooting intensity. Because of their more intensive sceletal and fine root system, beech trees can explore a larger amount of the soils volume and water reserve than Scots pine. On the investigated sandy soil fine roots of beech show the highest frequency in the upper mineral layer (5 to 40 cm depth), not or unimportantly reducing the frequency of the Scots pine roots. On the contrary, the frequency of fine roots of Scots pine is the highest in the organic and upper mineral layer of mixed stands with advanced planted beech trees, which can be explained by the better nutrition status of the mixed stands and the repression of the competition of the ground vegetation root system in the organic layer by the shadowing beech trees. The biomass to necromass ratio of both tree species is higher in mixed stands than in pure ones, but the root branching density is decreased.