Viability of thinning sessile oak stands by girdling

Abstract

he effects of girdling were analysed in a sessile oak (Quercus petraea Matts. Leibl.) forest with an 80-year-old coppice with standard structure in northern Spain. The study evaluated the viability of girdling as an alternative to felling trees during crown thinning. Eighty-four direct competitors of selected future crop trees were girdled by double notching and peeling. Three years after girdling, 100 per cent of the treated trees had died. Approximately half of the girdled trees did not resprout. The occurrence of basal sprouting was very low, and more than 35 per cent of the sprouts had very low vigour. No correlation was found between sprouting and the diameter of the girdled trees or the distance to their nearest neighbour. A negative relationship between the diameter of the girdled tree and the stage of decline was recognized. Girdling is an economic alternative to non-commercial thinning in oak stands and can be seen as an effective structural enrichment treatment.