title: Environmental control of the microfaunal community structure in tropical bromeliads.
abstract: Ecological communities hosted within phytotelmata (plant compartments filled with water) provide an excellent opportunity to test ecological theory and to advance our understanding of how local and global environmental changes affect ecosystems. However, insights from bromeliad phytotelmata communities are currently limited by scarce accounts of microfauna assemblages, even though these assemblages are critical in transferring, recycling, and releasing nutrients in these model ecosystems. Here, we analyzed natural microfaunal communities in leaf compartments of 43 bromeliads to identify the key environmental filters underlying their community structures. We found that microfaunal community richness and abundance were negatively related to canopy openness and vertical height above the ground. These associations were primarily driven by the composition of amoebae and flagellate assemblages and indicate the importance of bottom-up control of microfauna in bromeliads. Taxonomic richness of all functional groups followed a unimodal relationship with water temperature, peaking at 23-25°C and declining below and above this relatively narrow thermal range. This suggests that relatively small changes in water temperature under expected future climate warming may alter taxonomic richness and ecological structure of these communities. Our findings improve the understanding of this unstudied but crucial component of bromeliad ecosystems and reveal important environmental filters that likely contribute to overall bromeliad community structure and function.
authors.affiliation: School of Biological and Chemical Sciences Queen Mary University of London London UK; Biodiversity Research Centre and Department of Zoology University of British Columbia Vancouver BC Canada.
authors.forename: Pavel
authors.identifier: 0000-0002-9144-7937
authors.initials: P
authors.lastname: Kratina
authors.affiliation: Biodiversity Research Centre and Department of Zoology University of British Columbia Vancouver BC Canada; Department of Ecology and Evolution University of Salzburg Salzburg Austria.
authors.forename: Jana S
authors.initials: JS
authors.lastname: Petermann
authors.affiliation: Programa de Pós-Graduação em Ecologia Departmento de Ecologia Instituto de Biologia Universidade Federal do Rio de Janeiro (UFRJ) Rio de Janeiro RJ Brazil.
authors.forename: Nicholas A C
authors.initials: NA
authors.lastname: Marino
authors.affiliation: Biodiversity Research Centre and Department of Zoology University of British Columbia Vancouver BC Canada.
authors.forename: Andrew A M
authors.initials: AA
authors.lastname: MacDonald
authors.affiliation: Biodiversity Research Centre and Department of Zoology University of British Columbia Vancouver BC Canada.
authors.forename: Diane S
authors.initials: DS
authors.lastname: Srivastava
keywords: aquatic microfauna; community structure; environmental sorting; natural microcosms; protozoans; taxonomic richness; tropical bromeliads