| Summary: | 碩士 === 國立臺灣大學 === 海洋研究所 === 103 === Understanding predator-prey biodiversity relationship has been an important issue for ecology. Here, for the first time, we examined the biodiversity relationship and its consequences on trophic interaction between nanoflagellates (predators) and bacteria (prey) in the southern East China Sea. We obtained the nanoflagellates and bacterial biodiversity data through the sequences of 18S and 16S rDNA respectively with illumina Miseq, and abundance data by using epifluorescence microscopic and flow cytometry counting, respectively. Specifically, we evaluate the relationship between nanoflagellates and bacteria biodiversities and abundances after accounting for the environmental variables with linear regression and structural equation modeling analyses. Our results indicate that predator and prey diversity were positive related, suggesting bottom-up effects of prey diversity to promote predator diversity. For considering the possible selective behavior of nanoflagellates, we also examined the relationship between nanoflagellates and two functional groups of bacteria (autotrophic and heterotrophic bacteria). We found heterotrophic bacteria abundance increased with decreasing predator/prey diversity ratio, indicating that consumption of predators decreased with increasing prey diversity and decreasing predator diversity, which corresponds to the resource concentration hypothesis. We, however, did not find specific pattern for the autotrophic bacteria. Our results indicate that the bottom-up and top-down processes interactively controls bacterioplankton and nanoflagellates communities, and nanoflagellates responded differently to different functional groups of bacteria in the southern East China Sea.
|
|---|
