Divergent extremes but convergent recovery of bacterial and archaeal soil communities to an ongoing subterranean coal mine fire

Sang-Hoon Lee; Jackson W Sorensen; Keara L Grady; Tammy C Tobin; Ashley Shade

doi:10.7287/peerj.preprints.2446v2

Divergent extremes but convergent recovery of bacterial and archaeal soil communities to an ongoing subterranean coal mine fire

Sang-Hoon Lee^1,2, Jackson W Sorensen¹, Keara L Grady¹, Tammy C Tobin³, Ashley Shade ^1,4

1 Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States

2 School of Civil, Environmental, and Architectual Engineering, Korea University, Seoul, South Korea

3 Department of Biology, Susquehanna University, Selinsgrove, PA, USA

4 Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, Michigan, United States

DOI: 10.7287/peerj.preprints.2446v2

Published: 2016-12-21
Accepted: 2016-12-21

Subject Areas: Biodiversity, Ecology, Environmental Sciences, Microbiology, Soil Science
Keywords: press disturbance, soil, extremophile, resilience, community assembly, Centralia, anthropogenic, microbial diversity, thermophile, dormancy

Copyright: © 2016 Lee 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: Lee S, Sorensen JW, Grady KL, Tobin TC, Shade A. 2016. Divergent extremes but convergent recovery of bacterial and archaeal soil communities to an ongoing subterranean coal mine fire. PeerJ Preprints 4:e2446v2 https://doi.org/10.7287/peerj.preprints.2446v2

Abstract

Press disturbances are stressors that are extended or ongoing relative to the generation times of community members, and, due to their longevity, have the potential to alter communities beyond the possibility of recovery. They also provide key opportunities to investigate ecological resilience and to probe biological limits in the face of prolonged stressors. The underground coal mine fire in Centralia, Pennsylvania has been burning since 1962 and severely alters the overlying surface soils by elevating temperatures and depositing coal combustion pollutants. As the fire burns along the coal seams to disturb new soils, previously disturbed soils return to ambient temperatures, resulting in a chronosequence of fire impact. We used 16S rRNA gene sequencing to examine bacterial and archaeal soil community responses along two active fire fronts in Centralia, and investigated the influences of assembly processes (selection, dispersal and drift) on community outcomes. The hottest soils harbored the most variable and divergent communities, despite their reduced diversity. Recovered soils converged toward similar community structures, demonstrating resilience within 10-20 years and exhibiting near-complete return to reference communities. Measured soil properties (selection), local dispersal, and neutral community assembly models could not explain the divergences of communities observed at temperature extremes, yet beta-null modeling suggested that communities at temperature extremes follow niche-based processes rather than null. We hypothesize that priority effects from responsive seed bank transitions may be key in explaining the multiple equilibria observed among communities at extreme temperatures. These results suggest that soils generally have an intrinsic capacity for robustness to varied disturbances, even to press disturbances considered to be “extreme”, compounded, or incongruent with natural conditions.