Changes in microbial community structure following herbicide (glyphosate) additions to forest soilsAuthor(s): Alice W. Ratcliff; Matt D. Busse; Carol J. Shestak
Source: Applied Soil Ecology. 34(2-3): 114-124
Publication Series: Scientific Journal (JRNL)
Station: Pacific Southwest Research Station
Download Publication (464.0 KB)
Glyphosate applied at the recommended field rate to a clay loam and a sandy loam forest soil resulted in few changes in microbial community structure. Total and culturable bacteria, fungal hyphal length, bacterial:fungal biomass, carbon utilization profiles (BIOLOG), and bacterial and fungal phospholipid fatty acids (PLFA) were unaffected 1, 3, 7, or 30 days after application of a commercial formulation (Roundup®). In contrast, a high concentration of glyphosate (100× field rate) simulating an undiluted chemical spill substantially altered the bacterial community in both soils. Increases in total bacteria, culturable bacteria, and bacterial:fungal biomass were rapid following application. Culturable bacteria increased from about 1% of the total population in untreated soil to as much as 25% at the high concentration by day 7, indicating enrichment of generalist bacteria. Community composition in both soils shifted from fungal dominance to an equal ratio of bacteria to fungi. Functional diversity of culturable bacteria, estimated by C substrate utilization, also increased at the high glyphosate concentration, particularly in the clay loam soil. Unlike the other bacterial indices, only minor changes in bacterial PLFA resulted after the third day following the 100× field rate application. Apparently the herbicide resulted in an across-the-board stimulation of bacteria that was not reflected by the finer-scale PLFA community structure. Changes in fungal properties (hyphae, propagules, PLFA biomarkers) were few and transient. We conclude that the commercial formulation of glyphosate has a benign affect on community structure when applied at the recommended field rate, and produces a non-specific, short-term stimulation of bacteria at a high concentration.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationRatcliff, Alice W.; Busse, Matt D.; Shestak, Carol J. 2006. Changes in microbial community structure following herbicide (glyphosate) additions to forest soils. Applied Soil Ecology. 34(2-3): 114-124.
KeywordsSoil bacteria, Soil fungi, Phospholipid fatty acid, Carbon utilization, BIOLOG
- Bacterial associations with decaying wood : a review
- Tropical forest soil microbial communities couple iron and carbon biogeochemistry
- Analysis of hindgut bacterial phyla frequency and diversity in subterranean termites exposed to chitosan-treated wood
XML: View XML