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Combined effects of zooplankton grazing and dispersal on the diversity and assembly mechanisms of bacterial metacommunities
Author(s) -
Berga Mercè,
Östman Örjan,
Lindström Eva S.,
Langenheder Silke
Publication year - 2015
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12688
Subject(s) - metacommunity , biological dispersal , biology , ecology , trophic level , keystone species , predation , ecosystem , daphnia magna , biodiversity , population , chemistry , demography , organic chemistry , toxicity , sociology
Summary Effects of dispersal and the presence of predators on diversity, assembly and functioning of bacterial communities are well studied in isolation. In reality, however, dispersal and trophic interactions act simultaneously and can therefore have combined effects, which are poorly investigated. We performed an experiment with aquatic metacommunities consisting of three environmentally different patches and manipulated dispersal rates among them as well as the presence or absence of the keystone species D aphnia magna . D aphnia magna reduced both local and regional diversity, whereas dispersal increased local diversity but decreased beta‐diversity having no net effect on regional diversity. Dispersal modified the assembly mechanisms of bacterial communities by increasing the degree of determinism. Additionally, the combination of the D . magna and dispersal increased the importance of deterministic processes, presumably because predator‐tolerant taxa were spread in the metacommunity via dispersal. Moreover, the presence of D . magna affected community composition, increased community respiration rates but did not affect bacterial production or abundance, whereas dispersal slightly increased bacterial production. In conclusion, our study suggests that predation by a keystone species such as D . magna and dispersal additively influence bacterial diversity, assembly processes and ecosystem functioning.