The effect of cutting technique on the mortality and resprouting vigor of poplar stumps in short-rotation plantations

Abstract

Mechanical felling is the cost-effective solution for harvesting short-rotation poplar plantations, but the damage inflicted by conventional shear cutting devices on tree stumps has raised concerns about stump mortality and re-sprouting vigor - both crucial to coppice regeneration. In order to determine if such concerns are justified, the experiment monitored the survival and resprouting vigor of eleven sample blocks, composed of two 10-stump row segments cut according to either of two methods: 1) lternately with a chainsaw (control) or 2) and with an excavator-mounted shear. The sample blocks were located within the same plantation, established 7 years earlier with hybrid poplars (Populus nigra x P. deltoides), belonging to the "AF8" clone. One year after cutting, no differences were found between treatments in terms of stump mortality, number of shoots per stump, shoot diameter at 30 cm from the insertion and shoot height. These results support the use of mechanical shears to fell short-rotation poplar coppice. However, further studies should be conducted on multiple fields and clones for a safe generalization of this preliminary study.