2004年8月
Additive and non-additive effects from a larger spatial scale determine small-scale densities in a web spider Neriene brongersmai
POPULATION ECOLOGY
- ,
- 巻
- 46
- 号
- 2
- 開始ページ
- 129
- 終了ページ
- 135
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s10144-004-0187-7
- 出版者・発行元
- SPRINGER TOKYO
We examined 15 populations of Neriene brongersmai, a common sheet-web spider inhabiting cedar forest floor, to find out how density at a small spatial scale (patch level) is determined by processes operating at this scale as well as those from a larger spatial scale (population level). Here we focus on two types of large-scale effects that may influence small-scale density: an additive effect that changes the density at patch level; and a non-additive effect that changes the relationship between the density and its limiting factor at the patch level. ANCOVA showed that patch-level density of this spider was positively correlated with web-site availability at this level, but the density with a given amount of web-site differed among populations (cedar forests), indicating the existence of an additive large-scale effect. Multiple regression analysis showed that web-site availability at a population level explained the additive large-scale effect well, but prey availability and forest size did not. It seemed likely that increased web-site availability may have reduced the mortality of spiders while moving to a new web-site, and hence increased population density. A non-additive large-scale effect was also revealed: i.e. the relationship between density and web-site availability at the patch level tended to be stronger in populations with a greater additive large-scale effect. Higher intraspecific competition for web-sites in these populations appeared to have strengthened this relationship.
- リンク情報
- ID情報
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- DOI : 10.1007/s10144-004-0187-7
- ISSN : 1438-3896
- Web of Science ID : WOS:000223956800004