Annals of Forest Science

, Volume 68, Issue 4, pp 689–699

Climatic controls of a keystone understory species, Sasamorpha borealis, and an impact assessment of climate change in Japan


    • Department of Plant EcologyForestry and Forest Products Research Institute
  • Katsuhiro Nakao
    • Department of Plant EcologyForestry and Forest Products Research Institute
  • Tetsuya Matsui
    • Hokkaido Research Station, Forestry and Forest Products Research Institute
  • Motoki Higa
    • Department of Plant EcologyForestry and Forest Products Research Institute
  • Masahiro Horikawa
    • Toyota Biotechnology and Afforestation LaboratoryToyota Motor Corporation
  • Yuji Kominami
    • Kansai Research Center, Forestry and Forest Products Research Institute
  • Nobuyuki Tanaka
    • Department of Plant EcologyForestry and Forest Products Research Institute
Original Paper

DOI: 10.1007/s13595-011-0086-y

Cite this article as:
Tsuyama, I., Nakao, K., Matsui, T. et al. Annals of Forest Science (2011) 68: 689. doi:10.1007/s13595-011-0086-y



The aims of this study were to identify the climatic conditions controlling the distribution of Sasamorpha borealis and to assess the impact of climate change on the species in Japan.

Materials and methods

The relationship between S. borealis distribution and climatic variables in the Japanese Archipelago was explored using classification tree analysis. Potential habitat maps under the current and future climates were generated at about 1-km spatial resolution.


The model was highly accurate. Although snow cover has been thought to be the most important factor controlling S. borealis distribution, we revealed that the species requires high precipitation during the growing season even in humid Japanese environments. Areas with high summer (May–September) precipitation (PRS) were classified as potential habitat irrespective of other climatic conditions. In areas with moderate PRS, potential habitat was limited to cooler and less snow-covered areas and areas with low PRS were classified as non-habitat. The high fitness of the predicted to the observed distributions suggested that S. borealis could have survived throughout the Japanese Archipelago during the glacial period.


In future climates, 29.0–39.1% of the current potential habitat was predicted to change to non-habitat due to increasing dryness in the growing season. Areas with high precipitation remained a potential habitat for S. borealis.


Dwarf bambooSpecies distribution modelSnow coverSummer precipitationEmpty habitat

Supplementary material

13595_2011_86_MOESM1_ESM.pdf (257 kb)
Fig. S1The study area, including names of important regions of Japan (PDF 257 kb)
13595_2011_86_MOESM2_ESM.pdf (112 kb)
Fig. S2Distributions of S. borealis based on the SDD generated from Suzuki (1978). Black boxes indicate the presence of S. borealis. The spatial resolution is about 10 km (PDF 112 kb)
13595_2011_86_MOESM3_ESM.pdf (212 kb)
Fig. S3Spatial distributions of the five climatic variables under a the current climate, b the RCM20 scenario (2081–2100), and c the MIROC scenario (2081–2100). WI warmth index (Kira 1991), TMC temperature of the coldest month, PRS summer (May–September) precipitation, MSW maximum snow water equivalent, WR winter (November–April) rainfall (PDF 212 kb)
13595_2011_86_MOESM4_ESM.pdf (228 kb)
Fig. S4Changes in habitat types under the two climatic change scenarios; i.e., a the RCM20 scenario and b the MIROC scenario. “Suitable” in the legend refers to suitable habitat, “Marginal” indicates marginal habitat, and “Non” means non-habitat (PDF 227 kb)

Copyright information

© INRA and Springer Science+Business Media B.V. 2011