Regulation of Yield in Punjab Hill Forests

The paper sketches in brief the evolution of yield regulatory procedure adopted in Punjab since the inception of planned management in 1897, before which fellings had been irregular and essentially selective. After detailing the hill tract and forest types occurring thereon, different yield regulatory methods namely by (i) number of trees, (ii) area, (iii) volume, (iv) volume and increment and (v) volume and area based on periods, as adopted from time to time, have been discussed. The idea of reckoning the estimated increment towards yield from the Regeneration block was adopted by Trevor in 1919 and practised for sometimes after. It was abandoned later on because of the peculiar nature of the forests. Since the last war the emphasis has shifted towards conservative yield regulation wherein various periodic blocks have been included for prescribing annual yield. An allowance for volume of retained seed-bearers, fire insurers and compact groups of poles as advance growth in regeneration block under the Punjab Shelter-wood system is an effective step towards conservative yield. Similarly Hufnagi's and Von Mantel's formulae have been made use of as a guiding factor for fixing yield in forests being worked under Selection system.