Agricultural constraints on microbial resource use and niche breadth in drainage ditches
- Published
- Accepted
- Subject Areas
- Environmental Sciences
- Keywords
- Biodiversity, Bacteria, Decomposition, Microorganisms, Organic Matter, Ecosystem Functioning
- Copyright
- © 2017 Hunting et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Agricultural constraints on microbial resource use and niche breadth in drainage ditches. PeerJ Preprints 5:e3221v1 https://doi.org/10.7287/peerj.preprints.3221v1
Abstract
Background. Microorganisms govern important ecosystems processes, in particular the degradation of organic matter (OM). However, microorganisms are rarely considered in efforts to monitor ecosystem health and functioning. Evidence suggests that environmental perturbations can adversely affect microbial communities and and their ability to use available substrates. However, whether impacted microbial efficiencies in extracting and utilizing the available resources (resource niche breadth) translate to changes in organic matter (OM) degradation in natural systems remains poorly understood.
Methods. Here we evaluated effects of differences in organic matter (OM) related to agricultural land use (OM derived from ditches adjacent to grasslands, bulb fields and a pristine dune area) on microbial functioning. We specifically assessed 1) resource niche breadths of microbial communities during initial community assembly in laboratory microcosms and already established natural communities, and 2) how changes in community resource niche breadth translates to the degradation of natural OM.
Results. A disparity existed between microbial resource niche breadth in laboratory incubations and natural microbial communities. Resource utilization and niche breadth of natural microbial communities was observed to be constrained in drainage ditches adjacent to agricultural fields. This outcome coincides with retarded degradation of natural OM collected from ditches adjacent to hyacinth bulb fields. Microbial communities in bulb field ditches further showed functional redundancy when offered grassland OM of seemingly higher substrate quality.
Discussion. Results presented in this study suggest that agricultural practices can impose constraints on microbial functional diversity by reducing OM resource quality, which can subsequently translate to confined microbial resource niche differentiation and reduced organic matter degradation rates. This hints that assessments of actual microbial resource utilization and niche differentiation could potentially be used to assess the ecological health and functioning of natural communities.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Decotab mass loss
DECOTAB mass loss (mg. of organic matter derived from ditches adjacent to bulb fields and grasslands, incubated in ditches adjacent to both bulb fields and grasslands (n = 4 Two-way ANOVA showed significant effects of OM source (grassland ditch OM and bulb field ditch OM., but no effects of ditch type (grassland or bulb field).
water ecoplate
Microbial resource niche breadths (sqrt-Gower based nearest root distances. of microbial communities residing in both the water (A. and the sediment matrix (B. in ditches adjacent to bulb fields, grasslands, and pristine dune areas Mean (n = 6 ± sd. and corresponding letters indicate that microbial resource niche breadths are statistically similar (Gower-based NPermanova, Bonferroni-cerrected pairwise comparison, p > 005.
Ecoplate field
Microbial resource niche breadths (sqrt-Gower based nearest root distances. of microbial communities residing in both the water (A. and the sediment matrix (B. in ditches adjacent to bulb fields, grasslands, and pristine dune areas Mean (n = 6 ± sd. and corresponding letters indicate that microbial resource niche breadths are statistically similar (Gower-based NPermanova, Bonferroni-cerrected pairwise comparison, p > 005.