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Dynamics of bacterial populations in relation to carbon availability in a residue-amended soil

TitleDynamics of bacterial populations in relation to carbon availability in a residue-amended soil
Publication TypeJournal Article
AuthorsHu, SJ, van Bruggen, AHC, Grünwald, NJ
JournalApplied Soil Ecology
Date PublishedSep
competition, environment, extraction method, forest soils, growth, microorganisms, oligotrophic bacteria, organic-carbon, rhizosphere, size

Bacterial response to alteration in C availability is important in understanding the microbial community structure and microbial interactions in soil ecosystems. Population dynamics of oligotrophic and copiotrophic bacteria in relation to soil C availability were examined and relationships between bacterial populations and water-extractable C, buffer-extractable C, mineralizable C or microbial biomass C were investigated. Both copiotrophs and oligotrophs were significantly stimulated by newly added C in the form of cover crop debris, but copiotrophs rapidly peaked at the very early stage of cover crop decomposition while peak populations of oligotrophs occurred at a later stage when available C decreased. Despite significant correlations between mineralizable C and water soluble C or buffer soluble C, dynamics of both copiotrophic and oligotrophic bacteria was best related to mineralizable C pool. Copiotrophs were logarithmically correlated to mineralizable C (p < 0.0001), while oligotrophs were quadratically related to mineralizable C (p < 0.0001), which is, to our knowledge, the first report showing that high C availability may have inhibited oligotrophs in natural soils. Oligotrophs were not significantly correlated to microbial biomass C, suggesting that oligotrophs only contributed a minor part to the soil microbial biomass pool. (C) 1999 Elsevier Science B.V. All rights reserved.

Citation Key199