著者

Kondo Keiji

出版者

Research Faculty of Agriculture, Hokkaido University

雑誌

Journal of the Research Faculty of Agriculture, Hokkaido University (ISSN:13456601)

巻号頁・発行日

vol.75, pp.1-9, 2020-03

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Pelage insulation depends on the density and length of hair. Hair density is an important factor for determining the quality of fur and to help mammals adapt to their habitat. This study measured hair density and observed the morphology of the medulla in pelage of Japanese mustelids. Hair density was calculated from the number of hairs per hair bundle and the number of hair bundles per cm2. Morphological observations of the medulla were made with a scanning electron microscope(SEM). The hair density was highest in the sea otter(Enhydra lutris),followed by the river otter(Lutra lutra),the mink(Neovison vison),the ermine(Mustela earminea),the sable(Martes zibellina),the Japanese weasel (Mustela itatsi ),and the least weasel(Mustela nivalis ). The morphology of the medulla varied more than expected. This suggests that the medulla morphology could be used to identify a species in mammals. This study suggests the possibility for clarifying whether hair density and the morphology of the medulla depend upon taxonomy or habitat,by examining the pelage of species inhabiting different environments.

著者

Nitta Atomu Sawauchi Daisuke Chen Yongfu Akahori Hirokazu Yamamoto Yasutaka

出版者

Research Faculty of Agriculture, Hokkaido University

雑誌

Journal of the Research Faculty of Agriculture, Hokkaido University (ISSN:13456601)

巻号頁・発行日

pp.7-20, 2019-03

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The purpose of this study is to determine whether climate change will increase or decrease agricultural net revenue in Japan as a whole. This study conducts the first Ricardian model analysis of this issue and finds that agricultural net revenue will decrease across Japan by the end of the twenty-first century. The impacts of climate change are quite different in different regions of the country;an increase in agricultural net revenue is predicted in the northern municipalities, whereas agricultural net revenue is predicted to decline in many other municipalities.