Soil Functional Diversity Analysis of a Bauxite-Mined Restoration Chronosequence

Abstract

Soil microorganisms are sensitive to environmental 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 numbers, 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 significantly 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 physiological 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.

Adaptive Long-Term Monitoring of Soil Health in Metal Phytostabilization: Ecological Attributes and Ecosystem Services Based on Soil Microbial Parametersxs

“…Organization: structural (preferably, bacteria and fungi, the two major soil microbial taxa) and functional (e.g., ammonium oxidizers) diversity measurements via genetic profiles (PCR-DGGE). After all, changes in soil microbial community structure and Downloaded by [Selcuk Universitesi] at 12:37 21 December 2014 function can provide early signs of anthropogenic disturbances and predict restoration success (Lewis et al 2010). 3.…”

Open‐cut mining impacts on soil abiotic and bacterial community properties as shown by restoration chronosequence

“…Claassens et al (), on the one hand, found no association between rehabilitation time and the structure and function of microbial communities. Other studies, however, report that the structure of bacterial communities in reclaimed soils more closely compares to that of nonmined sites, with increasing time after restoration (Harris & Birch ; Lewis et al ; Banning et al ; Li et al ). These findings are consistent with spontaneous primary succession observed on spoil heaps retrieved from depths of up to 200 m (Sourkova et al ; Pietrzykowski ; Urbanova et al ).…”

“…At present, the global best practice for reclamation of open‐cut mines dictates that topsoil is stockpiled for the shortest time possible and then used to overlay reconstructed landscapes during revegetation (Lewis et al ; Dangi et al ; Rai et al ; Commonwealth of Australia ; Harris ; Mushia et al ). This practice is thought to safeguard physicochemical and biological characteristics of topsoil and thereby reduce the additional costs, which are associated with rehabilitation of sites using degraded topsoils (Commonwealth of Australia ).…”

Soil microbial community structure and function responses to successive planting of Eucalyptus

“…E-mail: zhenghua@rcees.ac.cn to environmental perturbations (Harris, 2003;van Dijk et al, 2009;Lewis et al, 2010;Banning et al, 2011) because of its rapid response to anthropogenic disturbances relative to soil biogeochemical properties. These responses have been assessed using soil biological indicators such as the phospholipid fatty acid (PLFA) profiles to reflect the structure of the soil microbial community (Iovieno et al, 2010), and soil enzyme activities to reflect their functional capacity (Rivas et al, 2009).…”