La Trobe

Rates of species turnover across elevation vary with vertical stratum in rainforest ant assemblages

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posted on 2024-05-28, 05:31 authored by Lily LeahyLily Leahy, BR Scheffers, AN Andersen, SE Williams
Climatic variation at local scales can influence both exposure and sensitivity of organisms and thereby scale up to influence population persistence and community composition across broader geographic extents. Tropical forest canopies are more climatically dynamic than the understorey. Consequently, the niche space of forest canopies has higher overlap in thermal conditions along elevation gradients, which imposes less of a climatic barrier to arboreal species than their ground-dwelling counterparts. We use ant communities of the Australian Wet Tropics to test the prediction that ground communities should have higher rates of species turnover over elevation compared to arboreal communities. We sampled ground and arboreal ants along elevation gradients at a bioregional scale that includes four mountain sub-regions. We assessed community composition at three spatial resolutions (regional, elevation, vertical) and then calculated beta diversity (species turnover) over elevation for ground and arboreal communities using null modelling procedures to compare different sized species pools. Vertical niche affinity was a strong contributor to overall biogeographic patterns; indicated by a strong interaction between vertical niche and elevation in beta diversity models. On average, the ground community exhibited a pronounced elevational distance–decay pattern while the arboreal community showed no pattern. Mean species turnover was 36% higher in ground than arboreal communities. Our findings suggest that the vertical niche has a pronounced effect on biogeographic patterns which has important implications for understanding the role of local scale climate conditions in shaping communities and for potential responses to future climate change.

Funding

Sloan Research Fellowship (BRS), The Explorer's Club (LL), Wet Tropics Management Authority (LL), Skyrail Rainforest Foundation (LL), Holsworth Wildlife Research Endowment - Equity Trustees Charitable Foundation (LL). LL was supported by a RTPS PhD scholarship from the Australian Government.

History

Publication Date

2024-05-01

Journal

Ecography

Volume

2024

Issue

5

Article Number

e06972

Pagination

12p.

Publisher

Wiley

ISSN

0906-7590

Rights Statement

© 2024 The Authors. Ecography published by John Wiley & Sons Ltd on behalf of Nordic Society Oikos This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.