Applicability of the Hemispherical Photography to Leaf Area Index Estimation in a Stand of Bamboo, Phyllostachys pubescens

摘要

We evaluate an applicability of the hemispherical photography for estimating leaf area index (LAI) in a stand of bamboo, Phyllostachys pubescens Mazel ex Houz. In the P. pubescens stand, ten successive thinning regimes were conducted, and the repetitive hemispherical photography was performed before and after each thinning. LAI estimated from the photographs was then compared with that estimated by the allometric technique. There was a significant correlation between LAI estimated by these two methods, suggesting the applicability of the hemispherical photography. However, LAI estimated by the photographic method was significantly larger than that estimated by the allometric method. The discrepancy of the estimated LAI might be due to the bias caused by the culms and branches taken in photographs. The Monte Carlo simulation indicated that at least, but not more than, 12 hemispherical photographs per plot with 25 m2 in area were necessary for stable estimation of LAI in a stand of P. pubescens. In conclusion, the hemispherical photography should be accepted as an effective alternative for estimating LAI in a stand of P. pubescens.