Influence of Stand Structure on Forest Biomass Sustainability

Abstract

A forest stand is a community where the interactions between trees and surroundings, result in a wide range of growth patterns that are also reflected in the stand biomass. The primordial features of stand structure description are structure (even-aged or uneven-aged) and composition (pure or mixed). The variability in structure and composition is high and it is reflected in the variability of growth and biomass as they are influenced by the interactions among individuals, nutrient and water uptake, light absorption, forest microclimate, density and tree distribution in space and time. Trees’ interactions in forest stands are complex and species traits and proportions are determinant to the growth and biomass patterns. Stand structure determines forest biomass and its sustainability in space and time. Overall it can be said the more diverse stands (mixed) enable higher biomass in space, higher variability in tree’s dimensions (uneven-aged) enable more constant biomass and time, and more complex structures (mixed uneven-aged) can store more biomass in space and time. The biomass sustainability is enhanced by short regeneration periods, by complementarity of species traits, by spatial arrangements promoting complementarity, by silvicultural practices of high frequency and low severity, by maintaining the harvest intensity at a growth resilience level, by the increase of length of the harvest cycles and by the maintenance of, at least, part of the residues to promote the biomass reallocation to the soil.