Determining the Effect of Felling Method and Season of Year on Coppice Regeneration

Abstract

There is increasing interest in plantations with the objective of producing biomass for energy and fuel. These types of plantations are called Short Rotation Woody Crops (SRWC). Popular SRWC species are Eucalypt (Eucalyptus spp.), Cottonwood (Populus deltoids) and Black Willow (Salix spp.). These species have in common strong growth rates, the capability to adapt to several weather conditions, the ability to coppice and rotations of 2-10 years. SRWC have generated interest for many forest products companies and timber producers and although they might help with the supply for the expected growth on the bioenergy and biofuels market, there are still several concerns about the best way to harvest them maximizing their ability to coppice. SRWC have elevated establishment and maintenance costs if compared to other type of plantations, but due the coppicing ability, the same plantation may be harvested up to 5 times without the need of establishing a new one. This will aid in the avoidance of the cost of establishing new plantations after the harvest. Study plots were installed at several locations in Florida, Mississippi and Arkansas, and were cut with a chainsaw and a shear head during summer and winter, to determine the effects of felling method and season on coppice regeneration. Thus, plots were divided in 4 treatments: shear-winter, saw-winter, shear-summer, saw-summer. Harvesting eucalypt trees during winter resulted in 96% of the stumps with coppice regeneration, while harvesting during summer resulted with 79% coppicing; however, there was no effect from felling method on coppice regeneration. A harvest season effect was observed on cottonwood, where harvesting during summer negatively affected coppice regeneration when compared to harvesting during winter. On the other hand, there was no significant effect observed on coppicing ability when trees were cut with the shear head or the chainsaw. Finally, no statistically significant difference was found on coppice regeneration of black willow when harvesting during winter or summer with a chainsaw or a shear head.