Community composition, and not species richness, of microbes influences decomposer functional diversity in soil

Roy, S and Karapurkar, J and Baidya, P and Jose, M and Bagchi, S (2023) Community composition, and not species richness, of microbes influences decomposer functional diversity in soil. In: Soil Biology and Biochemistry, 187 .

PDF Soi_bio_bio_187_2023.pdf - Published Version Restricted to Registered users only Download (6MB) | Request a copy

Abstract

Diversity-function relationships in producers, and how these are influenced by consumers, are well known. However, these are not well known for microbial decomposers in soil. It is also unknown whether and how consumers such as large mammalian herbivores influence soil microbial decomposer diversity-function relationships. We used a 14-year-old herbivore-exclusion experiment in the Trans-Himalayan drylands of northern India to address whether microbial functions vary with microbial diversity (both species richness and composition), and whether herbivores alter the diversity-function relationships. We analyzed soils from n = 10 paired grazed-and-fenced plots three times during the growth season of 2019. Data were from 16S rDNA gene amplicon sequencing of 7.6 million reads covering 1937 operational taxonomic units (OTU) of bacteria across 47 phyla (of which 924 OTUs were identifiable to genus level), and 1800 catabolic profiles across 30 substrates related to carbon metabolism. We found that functional diversity was positively related to microbial community composition, but not to species richness; it was also unaffected by large mammalian herbivore-exclusion to indicate resilience and resistance. This positive relationship between community composition and functional diversity challenges the prevailing notion of functional redundancy in hyper-diverse soil microbial communities since certain combinations of species could outperform others and determine decomposition processes and services. Structural equation models suggested that the strength of this relationship is favoured by availability of soil moisture. Microbial functions varied more strongly with temporal variables (e.g., seasonality) than with spatial variables (e.g., edaphic factors such as soil texture and pH). Although interpretations can be constrained by which and how many functions are investigated, the relationship was generalizable and robust once 16 or more functions were quantified. Decomposition in drylands may be particularly susceptible to how the identity of the microbial species, and not the number of species, responds to rising precipitation variability under ongoing and projected climate change. © 2023

Item Type:	Journal Article
Publication:	Soil Biology and Biochemistry
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to Elsevier Ltd.
Keywords:	Bacteria; Climate change; Mammals; Redundancy; Soil moisture; Textures, Distance-based; Distance-based structural equation model; Diversity function; Dry land; Ecosystem functions; Functional diversity; Functional redundancy; Microbial decomposers; Species richness; Structural equation models, Biodiversity, biodiversity; community composition; decomposition analysis; dryland farming; ecosystem function; microbial community; pH; soil microorganism; soil texture; species richness, India
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change
Date Deposited:	28 Feb 2024 12:07
Last Modified:	28 Feb 2024 12:07
URI:	https://eprints.iisc.ac.in/id/eprint/83651

Actions (login required)

View Item