Effects of residual trees on tree height of 18-and 19-year-old Cryptomeria japonica planted in group selection openings
Authored by Kenichi Yamashita, Nobuya Mizoue, Satoshi Ito, Akio Inoue, Hideaki Kaga
Date Published: 2006
DOI: 10.1007/s10310-005-0197-0
Sponsors:
Japanese Society for the Promotion of Science (JSPS)
Platforms:
R
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
This study examined the effects of residual trees on the height of 18-
and 19-year-old Cryptomeria japonica planted in group selection openings
of about 0.1ha at Yufuin in Oita Prefecture in southern Japan. We first
developed a general model expressing variation in the height for all of
the planted trees within the openings from indices of both
between-cohort competition (the effects of residual trees) and
within-cohort competition (among the even-aged planted trees). The
between-cohort competition index was calculated both with and without
taking into account the direction that residual trees were positioned
from subject trees. The two models suggested that residual trees located
near the northern edge of the opening were not effective competitors for
light for the planted trees within the opening. In addition, our results
indicated that both between-cohort competition and within-cohort
competition are important for explaining tree height in closed stands
within group selection openings. Using the general model, we then
estimated the potential loss of height growth for locally dominant trees
within the openings that could be attributed only to the influence of
residual trees. These results indicated that in addition to the effect
of opening size, both the degree of crowding and the direction of
residual trees from the planted trees are important factors affecting
the height of individual trees planted in group selection openings.
Tags
growth
Competition indexes