Studies on Silver Fir Regeneration

Abstract

The problems of natural and artificial regeneration in fir, Abies pindrow Royle are discussed. The factors inimical to natural reproduction are reviewed. Field studies indicate that deep raw humus, large stand openings, and grazing are some of the important factors contributing to the failure of natural regeneration. In deep humus, the regeneration fails to establish because of poor development of roots and mycorrhiza. Few seedlings which survive the initial years develop good roots and mycorrhiza when the roots reach the mineral soil beneath. Due to difficulties in natural regeneration, artificial regeneration of fir forests is engaging active attention. In the fir zone, seedlings require 3½-years to reach the transplantable height of about 22 cm. To reduce the period of growth in the nursery, it was thought that low attitude nurseries might be helpful. Results of studies conducted in one such nursery at Shamshi (H.P.) are given, and show that germination could be increased and seedling mortality could be controlled through fungicidal seed treatment. However the height growth could not be improved even after soil acidification and introduction of mycorrhiza, due possibly to the inherent slow growth in fir and also because the soil pH which was lowered by acidification did not get stabilized due to high free calcium carbonate in the soil. Seedlings with mycorrhizal roots were healthier with green lusture and showed increase in dry weight over the control. Future line of work for the low altitude fir nurseries includes selection of suitable site with acid soils or containing low free calcium carbonate, selection of suitable seed provenance fortification of seedlings with mycorrhiza and stimulating height growth by using growth regulators.