Comparison of growth performance and leaf area index in hinoki cypress (Chamaecyparis abtusa) plantations 5 years after thinning
2009
Miyamoto, K.(Forestry and Forest Products Research Inst., Kochi (Japan). Shikoku Research Center) | Okuda, S. | Inagaki, Y. | Kodani, E. | Noguchi, M. | Itou, T.
We compared the growth performance and leaf area index (LAI) of hinoki cypress (Chamaecyparis obtusa) stands in Shikoku 5 years after 30-50% of trees in the stands had been thinned. LAIs measured by the plant canopy analyzer (LAI-2000, Li-Cor Inc.) were similar in the 30 and 50% thinned stands in 2007, suggesting speedy recovery of the amount of leaves in the heavily thinned (50%) stands. There were no marked differences in 5-year basal area (BA) increment among the stands. On an individual tree basis, the median growth rate of trunk diameter at breast height (DBH) increased with increasing LAI per unit BA (LAI/BA) and LAI per tree (LAI/stand density) in the thinned stands. In our study sites, no negative effect on the remaining trees by heavy thinning such as severe growth reduction is recognized at this time, and there was little difference in BA-basis stand growth between conventional and heavy thinning. Our results suggest that the increase in the amount of leaves on each tree contributed to an increase in the growth rates of the remaining trees in the thinned stands.
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