Allometric models to estimate timber and fuelwood of Dalbergia sissoo Roxb. by pruning classes under agroforestry system

Abstract

Several allometric models have been developed to estimate timber volume and biomass of Dalbergia sissoo, but none has been developed to estimate fuel wood weight of standing tree under agroforestry system. Furthermore pruning which is an important management practice of agroforestry has not been considered in almost all the available allometric models. To fulfill this gap a study has been carried out to develop allometric models for four selected pruning classes of D. sissoo under D. Sissoo – Paddy/Wheat agrisilviculture system. The four selected classes were 0, 25, 50, and 75 per cent pruning of total tree height. The study was carried out at Jawaharlal Nehru Krishi Vishva Vidyalaya (JNKVV) Jabalpur, Madhya Pradesh, India during 2013-14. The age of trees was 15 years and total 12 models were developed. All these models were tested in field conditions and were highly significant (p=0.01). These models precisely estimate the volume of large size timber (diameter > 10 cm), small size timber (7 cm < diameter < 10 cm) and fuelwood weight (4 cm < diameter < 7 cm) under different pruning classes separately. With the help of these models current, annual and periodic increment of timber and fuelwood can be estimated in standing trees. Models are also useful in cost estimation and benefit-cost calculations of D. sissoo based agroforestry systems.