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Microbial community responses to 17 years of altered precipitation are seasonally dependent and coupled to co-varying effects of water content on vegetation and soil C

Soil Biology and Biochemistry

By:
, ,
DOI: 10.1016/j.soilbio.2013.04.014

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Abstract

Precipitation amount and seasonal timing determine the duration and distribution of water available for plant and microbial activity in the cold desert sagebrush steppe. In this study, we sought to determine if a sustained shift in the amount and timing of precipitation would affect soil microbial diversity, community composition, and soil carbon (C) storage. Field plots were irrigated (+200 mm) during the dormant or growing-season for 17 years. Microbial community responses were assessed over the course of a year at two depths (15–20 cm, 95–100 cm) by terminal restriction fragment length polymorphism (T-RFLP), along with co-occurring changes in plant cover and edaphic properties. Bacterial richness, Shannon Weaver diversity, and composition in shallow soils (15–20 cm) as well as evenness in deep soils (95–100 cm) differed across irrigation treatments during July. Irrigation timing affected fungal community diversity and community composition during the dormant season and most strongly in deep soils (95–100 cm). Dormant-season irrigation increased the ratio of shrubs to forbs and reduced soil C in shallow soils by 16% relative to ambient conditions. It is unclear whether or not soil C will continue to decline with continued treatment application or if microbial adaptation could mitigate sustained soil C losses. Future changes in precipitation timing will affect soil microbes in a seasonally dependent manner and be coupled to co-varying effects of water content on vegetation and soil C.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Microbial community responses to 17 years of altered precipitation are seasonally dependent and coupled to co-varying effects of water content on vegetation and soil C
Series title:
Soil Biology and Biochemistry
DOI:
10.1016/j.soilbio.2013.04.014
Volume
64
Year Published:
2013
Language:
English
Publisher:
Elsevier
Contributing office(s):
Forest and Rangeland Ecosystem Science Center
Description:
9 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
155
Last page:
163