Abstract
Variation in the form-factors for stem surface area was studied in two even-aged pure stands of Japanese larch (Larix kaempferi). In the stands, all living trees were felled for stem analysis, and then the form-factors for stem surface area and stem volume at breast height and 0.7 and 0.5 in relative height, i.e., κ_b, κ_<0.7>, κ_<0.5>, λ_b, λ_<0.7> and λ_<0.5>, were calculated. The coefficients of variation (CV) of κ_<0.7> and κ_<0.5> ranged from 3.2 to 7.4% and from 3.9 to 8.8%, respectively. On the other hand, CV of κ_b ranged from 9.1 to 15.4%, indicating that the variation in κ_b was comparatively larger than those in κ_<0.7> and κ_<0.5>. The ratios of CV of form-factor for stem surface area to that for stem volume ranged from 0.3 to 0.6, indicating that the variation in the form-factors for stem surface area was smaller than that for stem volume. In conclusion, κ_<0.7> and κ_<0.5> would be effective form-factors in estimating the total stem surface area of a stand with the angle count sampling precisely.
