Environmental filtering vs. resource-based niche partitioning in diverse soil animal assemblages. (June 2015)

• Record Type: Journal Article
• Authors: Maaß, Stefanie; Maraun, Mark; Scheu, Stefan; Rillig, Matthias C.; Caruso, Tancredi
• Is Part Of: Soil biology and biochemistry. Volume 85(2015)
• Page Start: 145
• Page End: 152
• Publication Date: 2015-06
• Subjects: Stable isotopes -- Trophic niche -- Community structure -- Neutral theory -- Soil microarthropods -- Oribatid mites -- Coexistence mechanisms; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2015.03.005
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: Terrestrial invertebrates constitute most of described animal biodiversity and soil is a major reservoir of this diversity. In the classical attempt to understand the processes supporting biodiversity, ecologists are currently seeking to unravel the differential roles of environmental filtering and competition for resources in niche partitioning processes: these processes are in principle distinct although they may act simultaneously, interact at multiple spatial and temporal scales, and are often confounded in studies of soil communities. We used a novel combination of methods based on stable isotopes and trait analysis to resolve these processes in diverse oribatid mite assemblages at spatial scales at which competition for resources could in principle be a major driver. We also used a null model approach based on a general neutral model of beta diversity. A large and significant fraction of community variation was explainable in terms of linear and periodic spatial structures in the distribution of organic C, N and soil structure: species were clearly arranged along an environmental, spatially structured gradient. However, competition related trait differences did not map onto the distances separating species along the environmental gradient and neutral models provided a satisfying approximation of beta diversity patterns. The results represent the first robust evidence that in very diverse soil arthropod assemblages resource-based niche partitioning plays a minor role while environmental filtering remains a fundamental driver of species distribution. Highlights: Environmental filtering and resource-based niche partitioning are distinct processes. We used stable isotopes and traits to resolve these processes in oribatid mites. Species were arranged along an environmental, spatially structured gradient. Trait differences did not map onto species position along the gradient. Environmental filtering and not resource-based niche partitioning controls community structure.