ORCID

Abstract

AimWe investigated how local-scale environmental heterogeneity influences biodiversity patterns across broad biogeographic gradients, using intertidal microhabitats as a model system within one of the most environmentally stressful ecosystems on Earth.LocationIntertidal habitats at 26 locations (two rocky shore sites per location) across six continents, spanning 98° of latitude (38°S to 60°N).Time Period2019–2022.Major Taxa StudiedAlgae, sessile and mobile invertebrates.MethodsWe compared biodiversity and thermal environments across contrasting microhabitats (rock pools and adjacent emergent rock) along a latitudinal gradient, sampling during environmentally ‘milder’ and ‘harsher’ periods. Biodiversity was quantified using multiple richness metrics (mean, total, unique taxa) and functional diversity.ResultsMicrohabitat differences strongly influenced biodiversity patterns across latitude. Rock pools consistently supported higher taxonomic and functional diversity than emergent rock, irrespective of sampling period, reflecting their ability to buffer thermal extremes, particularly under harsher conditions. Mean species richness exhibited a non-linear, s-shaped latitudinal pattern, with lowest values near the equator and higher richness at mid-latitudes, diverging from classical Latitudinal Diversity Gradient expectations. Biodiversity differences between microhabitats were greatest in temperate regions and diminished at low latitudes, where extreme conditions constrained diversity across habitats.Main ConclusionsLocal environmental heterogeneity can substantially modify, and in some cases obscure large-scale biodiversity patterns. By mediating exposure to environmental stress, intertidal microhabitats provide insight into how fine-scale variability interacts with latitudinal stress gradients to shape biodiversity distributions. Incorporating microhabitat variability into biogeographic frameworks is important for understanding global biodiversity patterns and predicting ecological responses to climate change.

Publication Date

2026-02-17

Publication Title

Global Ecology and Biogeography

Volume

35

Issue

2

ISSN

1466-822X

Acceptance Date

2026-02-03

Deposit Date

2026-02-04

Funding

This work was supported by the European Regional Development Fund (ERDF) through the Ireland-Wales Cooperation Programme 2014-2022, Ecostructure project. National Research Foundation of South Africa, 64801. Fundação de Amparo à Pesquisa do Estado de São Paulo, #2016/24551-4, #317015/2023-0. Ministerio de Ciencia, Innovación y Universidades, PRE2018-086266. Fundação para a Ciência e a Tecnologia, LA/P/0101/2020, UIDB/04292/2020, UIDB/04326/2020, UIDB/04625/2020, UIDP/04326/2020. P.J.M. and A.J.E. were part-funded by the European Regional Development Fund (ERDF) through the Ireland-Wales Cooperation Programme 2014–2022 via the Ecostructure project (www.ecostructureproject.eu). C.D.M. and M.H.O. were funded by the National Research Foundation of South Africa (Grant number 64801). C.V. and V.M. received Portuguese national funds from FCT—Foundation for Science and Technology, through the projects UIDB/04326/2020, UIDP/04326/2020, and LA/P/0101/2020 and UIDB/04292/2020. A.S. is grateful for the Foundation for Science and Technology's support through funding UIDB/04625/2020 from the research unit CERIS (DOI: 10.54499/UIDB/04625/2020). R.A.C. and A.S.M. were funded by São Paulo Research Foundation (FAPESP), Brasil. Process Number #2016/24551-4 and National Council of Scientific Researches CNPq #317015/2023-0. J.S.-V. was supported by a FPI Grant (PRE2018-086266) from Ministerio de Ciencia, Innovación y Universidades (Project CGL 2017-82739-P) co-financed by ERDF European Union and Agencia Estatal de Investigación, Gobierno de España.

Keywords

biodiversity, biogeography, climate change, environmental heterogeneity, environmental stress, functional diversity, microhabitat, microrefuge, refuge, thermal buffering

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