Abstract:

The spatial distribution of foliage is the fundamental composition of crown structure, moreover, it is convenient to understand the mechanism of the energy convert to biomass above-ground through the crown by evaluating the spatial distribution of foliage and researching the relationship between foliage and factors in individual trees and stand. In Mao'er Mountains of Heilongjiang Province, 30 permanent sample plots in secondary forest were established where 3 401 biomass of living branches from 176 stem analysis sample trees with 10 different broad-leaved species were measured, 2007. This study presents 10 individual tree models for the prediction of vertical distribution of living crown. The 3 parameters Chapman-Richards model was used to estimate the distribution of the crown biomasses between the lower and upper limits of the crown. In the models for the relative cumulative living crown, parameters estimate results show that all coefficiens of determination are high more than 0.91 especially 0.98 for birch. The highest relative height at which the foliage reached its maximum point was 0.82 CL(crown length)for manchurian ash and the lowest was 0.52 CL for cork tree. The peak points for other species were between these two values, e.g. 0.66 CL for birch and 0.78 CL for oak. The percentage of foliage for broad-leaved species in secondary forestry at the top crown(above 0.3 CL)was very small, which in middle crown and below it(0.4 CL-0.8 CL)took about 60%-70% of total biomass, especially 72.22% for birch, 72.55% for poplar and the minimum was 57.51% for manchurian ash, however at under-part of the crown for all species occupied about 10% of total foliage. The models can be used for the planning of harvesting operations, for the selection of feasible harvesting methods, and for the estimation of nutrient removals of different harvesting practices.

Key words: natural secondary forestry, foliage, cumulative crown biomass model, crown length