Allometric relationships for needle area of different needle age classesin young Scots pines: needles, branches and trees

Abstract

Summary Allometric equations describing projected needle area of individual branches and of the entire crown were developed and studied for 10-year-old Scots pine (Pinus sylvestris L.) trees. Height profile and needle characteristics were analysed for different needle age classes. At the branch level, relationships with branch diameter, branch length and whorl position were the best fitted equations to predict projected needle area. Specific leaf area decreased with needle age. A general logistic equation predicted the vertical distribution of projected needle area of different needle age classes as well as total needle area. At the tree level, the relationships with stem diameter at breast height, tree height and crown length fitted best the projected needle area of different needle age classes and the total needle area. For 4.5‐5.6 m tall trees with a mean diameter at breast height of 7.16 cm, the total projected needle area was 13.46 m 2 . The projected needle area to sapwood area relationship was described by a linear equation for different needle age classes and for total needle area. However, the relationship was stronger with sapwood area at crown base as compared with at breast height. The results are useful for scaling-up needle area from individual branches or from sapwood area to entire trees in Scots pine.