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Title: Predator dispersal influences predator distribution but not prey diversity in pitcher plant microbial metacommunities
Abstract The spatial distribution of predators can affect both the distribution and diversity of their prey. Therefore, differences in predator dispersal ability that affect their spatial distribution, could also affect prey communities. Here, we use the microbial communities within pitcher plant leaves as a model system to test the relationship between predator (protozoa) dispersal ability and distribution, and its consequences for prey (bacteria) diversity and composition. We hypothesized that limited predator dispersal results in clustered distributions and heterogeneous patches for prey species, whereas wide predator dispersal and distribution could homogenize prey metacommunities. We analyzed the distribution of two prominent bacterivore protozoans from a 2‐year survey of an intact field ofSarracenia purpureapitcher plants, and found a clustered distribution ofTetrahymenaand homogeneous distribution ofPoterioochromonas. We manipulated the sources of protozoan colonists and recorded protozoan recruitment and bacterial diversity in target leaves in a field experiment. We found the large ciliate,Tetrahymena, was dispersal limited and occupied few leaves, whereas the small flagellatePoterioochromonaswas widely dispersed. However, the bacterial communities these protozoans feed on was unaffected by clustering ofTetrahymena, but likely influenced byPoterioochromonasand other bacterivores dispersing in the field. We propose that bacterial communities in this system are structured by a combination of well dispersed bacterivores, bacterial dispersal, and bottom‐up mechanisms. Clustered predators could become strong drivers of prey communities if they were specialists or keystone predators, or if they exerted a dominant influence on other predators in top‐down controlled systems. Linking dispersal ability within trophic levels and its consequences for trophic dynamics can lead to a more robust perspective on trophic metacommunities.  more » « less
Award ID(s):
1754449
PAR ID:
10393046
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Ecology
Volume:
104
Issue:
4
ISSN:
0012-9658
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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