WILD BOAR (SUS-SCROFA-SCROFA L) ROOTING AND FOREST REGENERATION ON PODZOLIC SOILS IN THE NETHERLANDS

Phenology and the effects of rooting by wild boar on soil chemistry an d forest regeneration were studied by stratified sampling, in deciduou s and coniferous forests on acidic, podzolic soils in the central part of the Netherlands. At increasing degrees of soil scarification, thre e types of rooting were distinguished. Rooting phenology was dominated by superficial rooting in the litter layer, with highest frequencies in deciduous forests. Mast availability increased rooting activities i n winter and summer, but the effects of season, soil morphology, or ro ot abundance could not be established. No effect of rooting on soil pH , organic matter, and N-contents could be established. No evidence was found that singular, very intensive rooting, resulting in mixture of soil horizons, favoured conditions for germination and growth in stand s of beech (Fagus sylvestris), Douglas-fir (Pseudotsuga menziesii), Ja panese larch (Larix kaempferi), and pedunculate oak (Quercus robur). I n practice, the boar visited the same spots regularly, and no effect o f rooting could be established on regeneration of European black cherr y (Prunus padus), American black cherry (P. serotina), birch (Betula p ubescens and B. pendula), rowan (Sorbus aucuparia), holly (Ilex aquifo lium), Scots pine (Pinus sylvestris), Douglas-fir, Norway spruce (Pice a abies), and Japanese larch. Regeneration of oak (Quercus robur and Q . petraea), red oak(e. rubra), and beech was negatively correlated wit h rooting frequency.