Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS20] Mountain Science

Mon. May 27, 2019 10:45 AM - 12:15 PM 103 (1F)

convener:Keisuke Suzuki(Department of Environmental Sciences, Faculty of Science, Shinshu University), Yoshihiko Kariya(Department of Environmental Geography, Senshu University), Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chiyuki Narama(Niigata University, Department of Science), Chairperson:Akihiko SASAKI

11:30 AM - 11:45 AM

[MIS20-10] Formation process of small stands of Abies mariesii forest in pseudo-alpine zone on Mt. Akita-komagatake, northern Japan

*Asaka Konno1 (1.International Research Institute of Disaster Science, Tohoku University)

Keywords:Abies mariesii forest, formation process, Mt. Akita-komagatake, pseudo-alpine zone

The coniferous forest (largely composed of Abies mariesii) is presently the typical vegetation of the subalpine zone in Japan. However, around Mt. Akita-komagatake, in northern Japan, the expected predominance of A. mariesii is not extensively observed, and the predominant vegetation is instead the dwarf bamboo (Sasa kurilensis) grasslands and broad leaf forests. It’s called Pseudo-Alpine zone. According to pollen analysis, this vegetation is assumed to be attributed to unsatisfactory expansion of A. mariesii forest.

Here we clarify the formation process of small stand of the A. mariesii forest by its size structure and process of regeneration.

The surveyed area is located in the northern Mt. Akita-komagatake. We classified the vegetation and measured DBH (diameter at breast height) and created frequency histograms of size structure on each vegetation.

The both histograms of A. mariesii thick and thin forest display gradual decreasing on the small classes on the X axis (DBH). The maximum classes of DBH are the class of 20-30 cm on the both histograms. The decreasing is considered to be brought about by two reasons: the second generation of A. mariesii on 20-30 cm DBH class is not enough equipped to propagate, and there is less numbers of first generation. These results are indicated that the small stands of A. mariesii forest rapidly formed by second generations.