Beyond pH and macronutrients: Soluble manganese and habitat heterogeneity shape multi-taxon soil biodiversity across a wide regional environmental gradient
Olmo-Gilabert, Ruben (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Pons, Matias (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Polling, Marcel (Wageningen University & Research)
de Groot, G. Arjen (Wageningen University & Research)
Comas, Lluís (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Fernández-Martínez, Marcos (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Domene, Xavier (Universitat Autònoma de Barcelona)

Date:	2026
Abstract:	Global change threatens biodiversity across ecosystems worldwide, yet soil biodiversity remains comparatively poorly understood due to the challenges of quantifying belowground life. As a result, its main drivers and spatial patterns remain unresolved across environmental gradients. Here, we analyzed soil biodiversity across 102 sites in the north-eastern Iberian Peninsula, spanning ecosystems from arid to boreal (alpine) biomes. Using multi-taxon DNA metabarcoding, we assessed richness and Shannon diversity of bacteria, fungi, nematodes, and microarthropods and related these patterns to climatic variables, soil physicochemical properties, habitat and vegetation heterogeneity, and anthropogenic context. Diversity patterns showed coordinated variation among groups. Microbial diversity was strongly associated with soil pH-dependent nutrient relationships: soluble manganese (Mn) emerged as a key predictor of microbial diversity, showing positive effects under alkaline conditions, while calcium (Ca) covaried with pH and aluminium (Al) in ways consistent with constraints on bacterial communities, i. e. Ca alleviating Al toxicity in acidic soils, favouring bacterial diversity. Fungal richness also showed nutrient-related signals, negative with higher total nitrogen or nitrates with low pH, but positive with higher available phosphorus in alkaline conditions. In contrast, soil-fauna diversity was primarily linked to habitat structure and heterogeneity: richness increased with structural vegetation heterogeneity, amplified under high shrub cover for nematodes and varied with annual temperature and tree cover for microarthropods. Overall, combining soluble soil chemistry with reproducible habitat-heterogeneity indices in a compact regional design reveals how driver sets differ across trophic groups and improves the mechanistic interpretation of multi-taxon soil biodiversity patterns.
Grants:	Agencia Estatal de Investigación PRE2020-092743 European Commission 101076740 Agencia Estatal de Investigación RYC2021-031511-I
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	PH-Mn interaction ; Soluble micronutrients ; Vegetation structural heterogeneity ; Metabarcoding ; Nematodes ; Soil microarthropods
Published in:	Geoderma, Vol. 47 (July 2026) , art. 117858, ISSN 1872-6259

DOI: 10.1016/j.geoderma.2026.117858

14 p, 5.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Articles > Research articles
Articles > Published articles