Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/47936
Title: | 調適型遷移對競爭消費者的影響 Effects of Directed Dispersal on Competing Consumers |
Authors: | Wei-Ting Lin 林瑋庭 |
Advisor: | 三木健(Takeshi Miki),謝志豪(Chih-hao Hsieh) |
Keyword: | 遷移模式,關聯群聚,競爭共存,遷移對適應度的影響, Dispersal mode,metacommunity,competitive coexistence,adaptiveness, |
Publication Year : | 2011 |
Degree: | 碩士 |
Abstract: | 在具有空間結構的環境中,生物在不同區塊 (patch) 間隨機的遷移被認為可以促使競爭物種共存。然而,有些生物會利用適應度 (fitness) 的相關線索 (cue),主動修正他們移動的方向和強度,稱為調適型遷移 (directed dispersal)。調適型遷移,尤其是當其對適應度有利時,對物種競爭有何影響目前則尚未有定論。本研究以兩區塊、兩種消費者競爭同一資源的關聯群聚 (metacommunity) 模型探討這一重要問題。我們比較了在三種遷移模式下,遷移對兩種消費者共存的影響;三種模式包括隨機遷移與兩種分別以當地資訊和整體資訊為基礎的調適型遷移。對於調適型遷移是否增進適應度,我們也建立判斷準則,並以遷移對適應度的影響 (adaptiveness) 解讀結果。我們發現 (1) 以當地資訊為基礎的遷移模式可能降低適應度,在此情況下,促進共存的機制與遷移為隨機時相同。此外,(2) 在調適型遷移增加適應度的情況下,原為弱勢的競爭者若移動能力較佳,可以快速集中到資源較多的區塊,因此與優勢競爭者共存。此為生物遷移促進共存的新機制。本研究也顯示,生物的適應行為,對遷移促進物種共存的機制而言相當重要。 Random dispersal has been considered to promote species coexistence in spatially structured environments. However, dispersal can be directed, which means dispersal is motivated by fitness-related cues. The effects of directed dispersal, especially which improves fitness of individual (i.e. adaptive dispersal), on the coexistence of competing species remain unclear. We address this important question by constructing a two-patch metacommunity model of two consumers competing for a single resource. We compared the effects of dispersal on coexistence of consumers between three different modes: a random mode and two directed modes using local or global information of resource availability. We interpreted competitive outcomes in terms of adaptiveness of dispersal. We found that (i) directed dispersal based on local information can be maladaptive and promote coexistence in the same way that random dispersal does. In addition, (ii) when directed dispersal is adaptive, the inferior competitor with high moving ability can take advantage by tracking the patch of higher resource level, and thus coexistence is possible. This is a new mechanism of dispersal-mediated coexistence. These results strongly imply the importance of adaptive behavior in dispersal-mediated coexistence of competing species. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/47936 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 海洋研究所 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
ntu-100-1.pdf Restricted Access | 826.85 kB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.