Yatsugatake Research Articles

Diets of sika deer invading Mt Yatsugatake and the Japanese South Alps in the alpine zone of central Japan

Sika deer Cervus nippon populations have been increasing on the Japanese archipelago. Their range is expanding to include the alpine zone in central Japan, where they stay during summer before descending to the lower areas during winter. No studies on dietary habits of alpine deer in mainland Japan have been conducted. This study assessed the composition of sika deer diets and compared nutritional quality between the low montane, subalpine and alpine zones. We analyzed sika deer fecal samples from Mt Yatsugatake (YT) and the Japanese South Alps (SA). In the lower mountain in YT, dwarf bamboo comprised 40–55% of the plant compositions in fecal samples, whereas dicots were mostly found in SA samples. In subalpine zones in YT, grasses are an important food item, comprising about 50% of the samples. In SA, monocots (10–20%) and dicots (10–20%) were both prevalent. In the alpine zone of both YT and SA, grasses were present the fecal samples (50% and 10–20%, respectively). Crude protein contents were higher at higher zones (15–20%) than at lower zones (8–12%) in both study areas.

Trace element abundances in the Quaternary volcanic rocks of the Norikura volcanic chain, central Honshu, Japan.

Abundances of 16 trace elements including rare earths are determined by the instrumental neutron activation analysis for the Quaternary volcanic rocks of central Honshu, Japan. There is no systematic lateral variation along the Norikura volcanic chain except for the older part of Ontake volcano and Ueno volcano. The across-arc variation along the transverse through Yatsugatake-Norikura-Hakusan volcanoes does not reveal a regular increase in the incompatible element abundances away from the volcanic front. Based on the incompatible element abundances normalized to SiO2 = 50%, volcanoes in central Honshu are grouped into three, that is, Myoko and Kurohime (MK & KH), Yatsugatake (YT) and Norikura volcanic chain and Hakusan (NVC & HK) in increasing order. This variation can be explained by the difference in degree of partial melting and of the local enrichment of K and Rb in Myoko and Kurohime volcanoes.