Functional resilience of microbial communities from perturbed upland grassland soils to further persistent or transient stresses

• Published in: Soil biology & biochemistry Vol. 38; no. 8; pp. 2300 - 2306
• Main Authors: Kuan, H.L., Fenwick, C., Glover, L.A., Griffiths, B.S., Ritz, K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2006; New York, NY Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; biodegradation; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; community structure; copper; disturbed soils; ecological function; Function; Fundamental and applied biological sciences. Psychology; Grassland; grassland soils; Microbiology; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant residues; Resilience; soil chemical properties; Soil microbial community; soil microorganisms; soil pollution; soil pore water; soil respiration; Soil science; Stability; stress tolerance; toxicity; upland soils; viability; Scotland; Grassland; Function; Soil microbial community; Stability; Resilience; Microbial activity; Upland area; Stress; Transients; Upland soils; Soil science; Microbial community; Grassland soil
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2006.02.013

The microbial functioning of soils following perturbation was assessed at a temperate upland grassland site, maintained by the Soil Biodiversity and Ecosystem Function Programme at Sourhope Research Station, Scotland. Published results indicated that the soil microbial communities were resilient to these initial perturbations; in this paper we tested whether they were equally resilient to a subsequent perturbation. Soil samples were taken from field plots receiving treatments that represented different forms of perturbation, viz. reseeding, application of sewage-sludge, biocide or nitrogen plus lime, and a non-perturbed control. Functional resilience following further perturbation comprising a transient heat or persistent copper perturbation was assessed over 28 days, by monitoring the short-term decomposition of added plant residues. Bacterial community structure was assessed by DGGE separation of eubacterial 16S rDNA PCR products. PCR-DGGE did not distinguish any significant difference ( P > 0.05 ) between the bacterial communities of soils under different treatments, showing differences only between treated soils and the untreated, control soils. Two days after the application of stresses, functional capability differed in soils under different treatments. Soil samples from all the treated plots were less resilient to heat stress than soil from control plots. The initial reduction in decomposition following the addition of copper differed between treatments, but function had not recovered in any of the Cu-amended soils within 28 days. Soil resilience varied according to the type and duration of stress applied, microbial activity, soil characteristics and treatment regimes. The initial resistance of function to stress was not predictive of recovery of function over time.