Studies on continuous forest inventory system, 1: Comparison of survey-methods on the ground
1991
Yoshida, S. (Kagoshima Univ. (Japan). Faculty of Agriculture)
The aim of this study is to establish a nation-wide continuous forest inventory system, and this paper describes a comparison among the four survey-methods of sampling on the ground (point sampling, line sampling, circle plot method with constant radius, and circle plot method with two different radii) carried out on the basis of the sampling errors of present value estimation. In case of point sampling, d.b.h. and tree height of the counted trees by basal area factor (k=4) were measured. In line sampling, the line of the length 15m was located and the measurement of the counted-trees by k=4 was conducted the same as in point sampling. In circle plot method with constant radius, the plot area was fixed on 0.02 ha and in circle plot method with two different radii, they were fixed on 0.15 and 0.03 ha, respectively. Each method was carried out in Sugi (Cryptomeria japonica) stand of 55 years old, of Kagoshima University Forest in Kagoshima prefecture, Japan. Fifteen points were located systematically in this stand, and at each point each sampling method was conducted
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