Lateral root reinforcement in thinned and unthinned areas of Japanese cedar and Hinoki cypress plantations 6 to 11 years after thinning

Abstract

This study aimed to clarify the effect of thinning on the lateral root reinforcement of Japanese cedar [Cryptomeria japonica (L.f.) D. Don] and Hinoki cypress [Chamaecyparis obtusa (Siebold et Zucc.) Endl.] plantations. I compared the reinforcement of thinned and unthinned areas of five plantations each of Japanese cedar (6–11 years after thinning) and Hinoki cypress (6–8 years after thinning) in Mie Prefecture. Lateral root reinforcement was estimated by applying RBMw to the lateral root distribution data at the center between trees. In both species, reinforcement in the thinned and unthinned areas were similar, despite the dissimilar distance between trees, suggesting that reinforcement was only temporarily decreased after thinning and tended to recover. Moreover, reinforcement decreased with increasing distance between trees, and in Hinoki cypress plantations, thinned areas were larger than unthinned areas, for the same distance.