Operational and Environmental Comparison of Two Felling and Piling Alternatives for Whole Tree Harvesting in Quercus Coppices for Bioenergy Use

Coppices are a major potential source of forest biomass in Spain, where they occupy around 4M ha. Quercus coppices mostly neglected because their high harvesting costs and the small size products. This makes them very interesting to test compare alternative means for utilizing resources an optimized way. Hence, comparative study motor-manual mechanized felling bunching was conducted when thinning dense coppice stands two most important oak species Spain obtain bioenergy use. In particular, matched chainsaw manual piling against work drive-to-tree feller-buncher previously analyzed same sites. Productivity functions were fitted each species. The derived unit cost show that felling-bunching lower option both species, particularly smaller tree sizes. Nevertheless, strongly reduced loading times forwarding associated mechanization taken into account, total is often option. That true all sizes Q. ilex, trees larger than 13 cm diameter at breast height (DBH) pyrenaica. Residual stand damage low moderate, but always significantly greater compared with motormanual one. Soil alternatives. stumps experimented damages bunching, further research needed determine if those have any impact on stump mortality, sprouting capability future plants vigor. productivity level found ilex pyrenaica likely due narrower lighter crown latter.