SOIL MICROBIOLOGY Soil Functional Diversity Analysis of a Bauxite-Mined Restoration Chronosequence Dawn E. Lewis & John R. White & Denis Wafula & Rana Athar & Tamar Dickerson & Henry N. Williams & Ashvini Chauhan Received: 15 September 2009 / Accepted: 17 November 2009 / Published online: 18 December 2009 # Springer Science+Business Media, LLC 2009 Abstract Soil microorganisms are sensitive to environ- mental perturbations such that changes in microbial community structure and function can provide early signs of anthropogenic disturbances and even predict restoration success. We evaluated the bacterial functional diversity of un-mined and three chronosequence sites at various stages of rehabilitation (0, 10, and 20 years old) located in the Mocho Mountains of Jamaica. Samples were collected during the dry and wet seasons and analyzed for metal concentrations, microbial biomass carbon, bacterial numb- ers, and functional responses of soil microbiota using community-level physiological profile (CLPP) assays. Regardless of the season, un-mined soils consisted of higher microbial biomass and numbers than any of the rehabilitated sites. Additionally, the number and rate of substrates utilized and substrate evenness (the distribution of color development between the substrates) were signif- icantly greater in the un-mined soils with carbohydrates being preferentially utilized than amino acids, polymers, carboxylic acids, and esters. To some extent, functional responses varied with the seasons but the least physiolog- ical activity was shown by the site rehabilitated in 1987 indicating long-term perturbation to this ecosystem. Small subunit ribosomal DNA (SSUrDNA)-denaturing gradient- gel electrophoresis analyses on the microbiota collected from the most preferred CLPP substrates followed by taxonomic analyses showed Proteobacteria, specifically the gamma-proteobacteria, as the most functionally active phyla, indicating a propensity of this phyla to out-compete other groups under the prevailing conditions. Additionally, multivariate statistical analyses, Shannon's diversity, and evenness indices, principal component analysis, biplot and un-weighted-pair-group method with arithmetic averages dendrograms further confirmed that un-mined sites were distinctly different from the rehabilitated soils. Introduction A growing body of evidence suggests that changes in bacterial and fungal community structure and function can provide early signs of alternations in soil productivity and even predict restoration success. Restoration ecology has been extensively reviewed in several recently published articles (19 and references contained therein) with the consensus that further work is required to assess the role(s) of microorganisms in facilitating soil formation and reversing the detrimental effects of anthropogenic influen- ces, enhancing biodiversity, and ecosystem function of perturbed environments. Bauxite mining in Jamaica is performed by the opencast method and is likely a major threat to soil productivity by inducing perturbations to the soil microbiota that drive nutrient cycles. In the open cast bauxite mining method, the top 0–3 cm soils are stripped off and stock-piled alongside Electronic supplementary material The online version of this article (doi:10.1007/s00248-009-9621-x) contains supplementary material, which is available to authorized users. D. E. Lewis : D. Wafula : R. Athar : T. Dickerson : H. N. Williams : A. Chauhan (*) Environmental Sciences Institute, Florida A&M University, 1515, S. MLK Blvd., 305 FSHSRC, Tallahassee, FL 32307, USA e-mail: ashvini.chauhan@famu.edu J. R. White Department of Oceanography and Coastal Sciences, Wetland and Aquatic Biogeochemistry Laboratory, Louisiana State University, Baton Rouge, LA 70803, USA Microb Ecol (2010) 59:710–723 DOI 10.1007/s00248-009-9621-x