Plant-soil feedback in spruce (Picea abies) and mixed spruce beech (Fagus sylvatica) stands: a hypothesis linking chemical properties of the O-horizon with rooting patterns, soil water relations and stand transpiration : Forest Ecosystem Restoration. Ecological and Economical Impacts of Restoration Processes in Secondary Coniferous Forests

2000

S. 106-111

4 Abb., 11 Lit. Ang.

Unselbständiges Werk

200072892

Data from a survey of 28 adjacent stands of pure spruce and mixed spruce beech show a marked enrichment of calcium in the O-horizon of the mixed stands, in particular in relation to potassium and magnesium. Detailed studies of tree root distribution in soil pits on two of the sites show that spruce roots more shallow in mixed stands than in pure stands, while beech roots occupy the deeper soil horizons. This finding was confirmed by ground penetrating radar on one site. Beech uses much more water in these stands as shown by the heat dissipation method for water transport in the trunks. These findings were confirmed by studies on soil water depletion by the time domain reflectometry method. We hypothesize that in mixed spruce beech stands relative calcium enrichment in the O-horizon results both from higher transpiration of beech and uptake of water from deeper soil horizons, where the soil solution contains more calcium. Potassium and magnesium nutrition appears to be dominated by the litter fall - decomposition cycle.