Effect of sunlight condition determined by terrain on tree health of Japanese mountain cherry (Cerasus jamasakura (Siebold ex Koidz.) H. Ohba var. jamasakura) in Yoshinoyama, Nara Prefecture, Japan

Abstract

We studied effect of sunlight condition determined by terrain on tree health of Cerasus jamasakura (Siebold ex Koidz.) H. Ohba var. jamasakura in Yoshinoyama, Nara Prefecture, Japan. We selected 286 trees of C. jamasakura from the data of Nara Prefecture from 1993 to 1994 and analyzed it using a generalized additive model with tree health (good or no good) as an objective variable, and age class, accumulated amount of solar radiation during growing season and topographic wetness index as explanatory variables. As a result, old-age tree and solar radiation were statistically significant. C. jamasakura had tendency in an unhealthy state at sunny locations. It was considered that low water retention ability of soil promotes soil dryness at the level that adversely affects plants. It was indicated that north slopes where soil dryness is alleviated once were selected as planting sites for C. jamasakura at Yoshinoyama.