報告書番号

U03041

タイトル（和文）

イヌワシを頂点とする生態系の解明 -－GISと多変量解析を用いたノウサギ生息密度の予測と地図化－-

タイトル（英文）

Study on the ecosystem sustaining a pair of Golden Eagles -Predicting and mapping of Japanese hare density using GIS and multivariate analysis-

概要 （図表や脚注は「報告書全文」に掲載しております）

上位性の視点からの生態系影響評価手法を検討するため、秋田駒ケ岳のイヌワシ行動圏において、主要な餌動物であるノウサギと環境要因の関係を解析し、GISを用いて行動圏内の生息密度予測地図の作成と生息数の算出を試みた。 同一植生タイプのノウサギ生息密度はばらつきが大きく、植生タイプ間に統計的な有意差はなかった。植生タイプと、林冠高、標高、傾斜を説明要因として数量化Ⅰ類による分析を行なった結果では、予測値と実測値の間に高い相関が認められた。 数量化による予測式と、GISデータベースをもとに、ノウサギ生息密度予測地図を作成した結果、季節が異なるとパターンが異なり、同じ季節では年度が異なっても似たようなパターンを示した。 今後、他種への適用性、予測精度の評価、人為的な影響を説明要因として組み込む方法を検討する。

概要 （英文）

To examine the method of ecosystem impact assessment from the viewpoint of large predator species, we analyzed the relationship between environmental variables and densities of Japanese hares which are main prey for Golden Eagles, and constructed predictive maps of the hare densities in a home range of a pair of Golden Eagles on Mt. Akita-Komagatake. Since there were no significant differences among vegetation types, we analyzed the relationships between hare densities and vegetation types, canopy heights, altitudes, and slope inclinations by Hayashi’s quantification method Ⅰ. The result showed highly correlation between observed values from the field survey and predictive values by quantification models of hare densities. Based on quantification models and GIS database, we constructed predictive maps of Japanese hare densities. The result showed that high density areas in vegetation growing period distributed mainly on middle altitude, but those in snowy and leaf expanding period distributed mainly on relatively high altitude. Predictive maps in the same seasons showed similar distributional patterns even if the maps were constructed in different years. By using the predictive maps, we calculated numbers of Japanese hares in main forest types in a home range of a pair of Golden Eagles. In this study, we proposed the predictive models and maps of Japanese hare densities. Future studies are needed to evaluate the precision of predictive models and effects of human activities on the hare densities.

報告者

キーワード