Importance of crown architecture for leaf area index of different **Populus** genotypes in a high-density plantation
Faculty of Sciences. Biology
Tree physiology. - Victoria
, p. 1214-1226
University of Antwerp
Crown architecture is an important determinant of biomass production and yield of any bio-energy plantation since it determines leaf area display and hence light interception. Four Populus genotypesof different species and hybrids and with contrasting productivity and leaf areawere examined in terms of their branch characteristics in relation to crown architecture during the first and second growing seasons after plantation establishment. The trees were planted at high density (8000 ha−1) on two different former land use types, cropland and pasture. We documented significant differences in branch architecture among the genotypes and for the first year among the former land use types. Land use effects only affected factors not related to canopy closure and wood production, and decreased after the first growing season. This suggested that both former land use types were equally suited for the establishment success of a poplar bio-energy plantation. Tree height and branch dimensionsbranch diameter and branch lengthwere the most important determinants of wood production and maximum leaf area index. Despite the secondary importance of the number of sylleptic branches, these branches contributed significantly to the total leaf area in three out of the four studied genotypes. This indicated that enhanced syllepsis accelerates leaf area development and hence carbon assimilation, especially in the early stages of a high-density plantation with poplar.