NEEDLE AREA RELATIONSHIPS OF SCOTS PINE IN THE NETHERLANDS

To analyse the foliage area characteristics of Scots pines of different sizes, 12 trees were selected out of 4 stands of different ages. From the selected trees, total needle area and needle area distribution were estimated from branch samples. Stem discs were collected to determine sapwood area at breast height. Variation in specific leaf area (SLA), the relationship between sapwood area and needle area and the vertical distribution of the needle area in the tree crown were estimated. SLA decreased with needle age and increased with depth in the tree crown. Vertical distribution of the needle area within a tree crown was described by a generalized logistic model. The relationship between needle area and sapwood area was described by a linearized model. The ratio between needle and sapwood area ranged from 902 to 1295 cm2 cm-2.