ABSTRACT
An association between provenance variations in growth performance of the Japanese larch (Larix kaempferi) and climatic conditions in the provenances has been found in the natural distributional range in central Japan. To verify whether this association differs in northern Japan, outside of the original habitats, we examined stem productivity of 30-year-old trees planted in three test sites in the Nagano Prefecture in central Japan and three test sites in the Hokkaido Prefecture in northern Japan. The trees originated from 25 provenances throughout the whole range of the natural distribution. Stem-productivity variances of interactions between the test sites and provenances were relatively small. Provenance correlations in the stem productivity among most of the tests sites were positive. Climatic conditions in the provenances and test sites were summarized as two indices: a gradient of warmth and drought (higher temperature and less precipitation at lower elevations) and a cline of climatic seasonality (from the northwestern to southeastern sides of the Japanese mainland, with decreasing and increasing seasonal variations in temperature and precipitation, respectively). The maximum stem productivity among the provenances was frequently observed at both extremities of the warmth/drought gradient and on the southeastern side of the climate-seasonality cline. These associations were detected in test sites in both central and northern Japan. These findings suggest similar provenance variations in growth performance of the Japanese larch among different growing environments in Japan.
Acknowledgments
We thank the staff of the Chubu and Hokkaido regional forest offices as well as the Toshin, Hokushin, Kiso, Sapporo, Asahikawa, and Kitami district forest offices for their efforts to maintain the provenance test sites; Sayaka Fujii, Seiichi Kanetani, Takayuki Kawahara, Satoshi Kikuchi, Keiko Kitamura, Masahiro Masuda, Yoshinari Moriguchi, Keiko Nakamura, Toshihiko Nishiyama, Masato Otani, Tsuyoshi Seki, Kenichi Shimada, Setsuko Suzuki, Kyoko Tanaka, Yoshiaki Tsuda, Kentaro Uchiyama, Tokuko Ujino-Ihara, and Kensuke Yoshimura for their assistance in field measurement; Tokuko Ujino-Ihara for her help with data arrangement; Hiroki Itoh for his advice on the statistical analyses; and Wataru Ishizuka for his suggestions to improve the article.
Disclosure statement
The authors have declared that no competing interests exist.
Data availability statement
All relevant data are included in Data S1 and S2 of Electronic Supplementary Material. All data are fully available without restriction.
Supplementary material
Supplemental data for this article can be accessed here.