Structure and dynamics of biological communities determined by synergy of top-down and bottom-up effects

2017 Fiscal Year Final Research Report

• Project/Area Number: 26440247
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Osaka Prefecture University
• Principal Investigator: Namba Toshiyuki 大阪府立大学, 理学(系)研究科(研究院), 客員研究員 (30146956)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 生物群集 / 構造 / 安定性 / ボトムアップ効果 / トップダウン効果 / 食物網 / ギルド内捕食 / 植食者

Outline of Final Research Achievements

In order to elucidate the synergistic effect of top-down and bottom-up effects, two mathematical models were mainly analyzed. In the system consisting of herbivore and two species of plants, the extreme differences in preference of the herbivore and the eutrophication of the system produce violent population fluctuations, but the variation in populations caused by the circulation of nutrient through excrement of the herbivore turns out to be milder. In the intraguild predation model, in which one of the two predators sharing a common prey feeds on the other, three models are proposed to resolve the contradiction that the extinction of the intermediate predator predicted by theory is not supported by empirical observations, and further the top down effect by higher predators are clarified.

Free Research Field

数理生態学