Photosynthesis in Sitka Spruce (Picea sitchensis (Bong.) Carr.). III. Measurements of canopy structure and interception of radiation.
Presents part III of a study (earlier parts of which had different titles and were concerned with non-forest species) consisting of a detailed investigation in a 22-year-old stand in NE Scotland, of the vertical distribution of leaf, branch and stem mass and area, the angular distribution of needles on the shoots, and the grouping of shoots into branches. Mean transmittance and the distribution of transmittance of visible and near-infrared radiation were measured at four heights in the canopy along a 14-m transect. The distributions of transmitted radiation were strongly influenced by leaf area index, the inclination angle of the sun and the ratio of diffuse/direct light.