Permalink : http://hdl.handle.net/2115/49050

KEYWORDS : 融雪期;アカシボ;ざらめ雪;間隙性動物;snowmelt season;Akashibo red snow;granular snow;interstitial fauna

赤雪発生の調査を東北地方の47地点について行った. 原因の多くは尾瀬において見られるアカシボ現象と同様に, 多量の酸化鉄を含む粒子であった. 発生地域は融雪時期に積雪下層部と湿原もしくは土壌との境界面に融雪水の流れのある地点あるいは融雪水のとどまる地点であった. 赤雪消滅後の土壌には多量のSiと次いでFeおよび少量のAl, Mgなどが存在した.
Vertical distribution and activities of intranivean invertebrates were studied in snowmelt season in northern Japan. The intranivean invertebrates were dominated by copepods, dipteran larvae and oligochaetes,and they increased toward the bottom. High structural similarity between snow and soil animals strongly suggested that the intranivean invertebrates were derived from subnivean fauna. All the harpacticoids recovered from the less wet snow in the middle layers were died often with seriously damaged in their appendages. On the other hand, most of those in the lower and waterbearing layers of the snow showed active movement. Many precopulating pairs were found in the harpacticoids there. It is suggested that inundated granular snow in the late snowmelt season can provide interstices which harbor many small aquatic animals such as copepods and oligochaetes.