Commercial Thinning and Selective Cutting with Impacts on Forest Carbon

In even-aged management, thinning refers to the harvesting of timber and biomass through forest chronosequences extending from pre-commercial management to the final cutting and subsequent reforestation for the next rotation. Thinning includes the harvesting of trees in the pole and middle-aged phases. This increases tree spacing to enhance (i) the growth and development of the remaining trees and (ii) the provision of timber and biomass. Throughout a rotation, thinning involves the periodic removal of trees from below or above to achieve a given spacing of the remaining trees in patches, with the consequent growth and development faster than before thinning. Thinning removal includes (i) the proactive removal of timber otherwise lost in natural mortality and (ii) increased allocation of productivity to a smaller number of trees to enhance their growth and development from the thinning phase to tree maturity. In uneven-aged management, selective cutting focuses on the removal of larger individual trees, which create space for the natural regeneration and ingrowth of seedlings through the canopy of dominating large trees. In uneven-aged management, rotation is excluded, with the aim of maintaining a skewed forest structure. This implies that seedlings, young, and pole-phase trees are dominant among middle-aged and mature trees. This is achieved by harvesting maturing/mature trees for the manufacturing and energy industries facilitating the establishment of seedlings in canopy gaps and increasing growth of remaining larger trees.