Predators and priority effects suggested as potential drivers of microfauna communities in a community transplantation experiment along an elevational gradient

Abstract

Transplantation experiments are a useful method to identify responses of organisms to environmental change. However, they are typically restricted to single or few species. Our experiment was carried out using entire bromeliad‐inhabiting microfauna communities which were transplanted along an elevational gradient, simulating environmental change acting on the communities. Additionally, we manipulated trophic interactions, i.e. resource availability and predator presence, thus combining abiotic and biotic effects in a full‐factorial experimental design. Using this experiment, we found a strong signal of original elevation in microfauna community structure (abundance, evenness, functional composition) with a shift from amoeba‐dominated to flagellate‐dominated communities with increasing original elevation. Surprisingly, the transplantation of communities along the elevational gradient did not affect community structure, indicating strong priority effects. Predation decreased microfauna abundance and increased microfauna evenness, specifically in higher original elevation and high resource levels. In summary, our results suggest that microfauna communities in bromeliads might be primarily shaped by priority effects and predator presence. However, interacting effects (between predator presence and resource availability, as well as between predator presence and original elevation) highlight the usefulness of studies with full‐factorial experimental designs to understand community‐structuring processes. Bromeliads and other micro‐ecosystems provide convenient study systems for community level approaches that could be used in future studies concerning the effects of environmental change, for example climate change on community structure.

Investigation of an Elevational Gradient Reveals Strong Differences Between Bacterial and Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata

“…The extent to which microbes abide by the ecological laws of macrobes is still an open question. Few published studies of community changes across an elevational gradient have investigated phytotelmata [ 102 – 105 ], and none of these have compared microbes with macrobes. Aquatic microbial systems have also been understudied in macroecology relative to soil microbes [ 106 ], and protists are understudied relative to bacteria [ 18 ].…”

Colonization order of bacterial isolates on treefrog embryos impacts microbiome structure in tadpoles

“…Stochasticity in dispersal, for example, can result in differences in colonization order, causing otherwise equivalent habitats to develop differing community structures. These consequences of colonization order, commonly referred to as priority effects [3,4], are being explored in a variety of systems [5][6][7][8][9]. Priority effects are likely to be regulated by fitness differences between taxa (as defined in [10]) and the presence or absence of destabilizing, stabilizing or equalizing forces [5,11].…”

A proposed microcosm for landscape ecology – beyond the binary to the patch-mosaic model

“…Ecological research using microcosms has mainly focused on questions in community and population ecology and has successfully used them as a tool to examine topics such as dispersal (e.g., Grainger and Gilbert 2016), predator-prey dynamics (e.g., Busse et al 2019) and community assemblage (e.g., Pereira et al 2018). Although the microcosm as a whole is often referred to as a “landscape” (Drake 1993; Gilbert et al 1998), the experimental systems described above are all simple binary landscapes of habitat and non-habitat patches (i.e., pitcher plant leaves and the surrounding air, tide pools and the surrounding rocks).…”