Ailanthus triphysa in the Homegardens of Kerala: Occurrence, Basal Area, Average Standing Stock of Wood and Diameter Structure

Abstract

Variability in occurrence and standing stock of Ailanthus triphysa trees in Kerala was assessed using an inventory of 737 homegardens selected from 31 thaluks. The gardens were identified through a stratified random process in which one or two gardens/farmers each belonging to the small, medium and large holding size categories were randomly chosen per panchayath (5 or 6 random panchayaths in a thaluk). Highest basal area and standing stock of ailanthus wood were observed in Kunnathunad and Thrissur thaluks, while the highest relative frequency was noted at Vaikom. In general, ailanthus is more abundant in the midlands of central and southern Kerala, characterised by very deep, well drained, gravely clay soils on gently sloping coastal laterites or very deep, well drained, gravely clay soils with moderate surface gravelliness on gently sloping midland laterites. Inter- and intra- thaluk variations in ailanthus occurrence can be attributed to a combination of soil and market factors, besides personal preferences of the farmers. A negative linear diameter distribution pattern implies less than adequate representation in the pole stage crop.