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Maximum yield and the C‐D effects in natural white birch stands
Author(s) -
Shibuya Masato
Publication year - 1994
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/bf02348419
Subject(s) - betula platyphylla , allometry , mathematics , yield (engineering) , competition (biology) , constant (computer programming) , zoology , dry weight , botany , biology , ecology , physics , thermodynamics , computer science , programming language
The competition‐density effect for natural Japanese white bitch ( Betula platyphylla var. japonica ) stands, located in the northern part of Hokkaido Island, was examined for various growth stages to establish mean tree weight‐density relationships over a considerable extent of stand growth of white birch. Aboveground yields of investigated stands ranged from 16.0 to 161.7 t·ha −1 , and it was recognized that maximum aboveground yield of this species was about 160 t·ha −1 . Constants A and B of the reciprocal equation of the C‐D effect, 1/w= A N+ B (w, mean tree weight; N, tree density), were related to mean height classes of birch stands. Constant B was related to the entire mean height classes as the allometric relationship. On the other hand, constant A had an allometric relationship to mean height classes under 16 m, but became fixed over the 16 m class. White birch stands can come up to the maximum yield approximately at the stage of the 16 m class. The asymptotic tendency seemed to be appropriate for constant A ‐mean height class relationship. The maximum yield of white birch stands was predicted by the asymptotic value of A . The trend of mean tree weight‐density relationships with stand growth also changed with constant A . It was considered that maximum yield was an important characteristic for practical applications of the C‐D effect to agriculture and forestry.