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The effect of missing rings on stand‐age estimation of even‐aged forests in northern Hokkaido, Japan
Author(s) -
Takaoka Sadao
Publication year - 1993
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/bf02347193
Subject(s) - crown (dentistry) , core (optical fiber) , missing data , estimation , age structure , mathematics , forestry , physical geography , statistics , geography , demography , physics , medicine , population , management , dentistry , sociology , optics , economics
Abstract The effectiveness of estimating stand age from increment core samples taken at stump height (20 cm above ground) was tested in an even‐aged stand of Betula ermanii that had regenerated after a forest fire in 1945 in Hokkaido, Japan. Careful cross‐dating revealed that annual rings were missing in 11 cores out of a total of 42 cores sampled, and that all these missing rings occurred in the outermost part of the core. These facts indicate that precaution has to be taken in selecting trees from which cores are to be sampled. The present work also revealed that those trees with missing rings have a characteristic appearance, with a thinner stem and less crown foliage than normal trees with complete rings. It was also found that even if this appearance test failed, the possibility of missing rings could be detected from a declining growth pattern, with extremely narrow rings on the increment core which normal trees did not show.