Forest Production and the Organization of Foliage within Crowns and Canopies
Forest Ecology and Management
A non-foliated area (or ‘bare inner core’) develops in the interior of tree crowns as the size of the crown increases during stand development. We examined the relationship between mean bare core volume and both stand density and mean crown volume, and its association with the production of stemwood volume for two conifer species, Pinus contorta var. latifolia and Abies lasiocarpa. Mean bare core volume decreased with absolute stand density and increased with mean crown volume for both species. As crown size increased, so did the proportion of total crown volume occupied by the bare core. Small bare core volumes were associated with small, efficient crowns, and large bare core volumes were associated with large, less efficient crowns. Mean bare core volume was negatively related to the mean ratio of crown surface area to volume but was not correlated with an index of crown slenderness, two characteristics which are assumed to be important in the development of crop tree ideotypes. The small mean bare core volume and associated increased efficiency of stemwood production at high stand densities increased per hectare productivity for both species, thereby indicating how differing density management regimes influence stand production.
Jack, S.B. and J.N. Long (1992). Forest production and the organization of foliage within crowns and canopies. Forest Ecology and Management, 49(3-4): 233-245.