A Comparison of Microbial Community Function and Structure in Rehabilitated Asbestos and Coal Discard Sites

Abstract

Previous studies have made some progress with the use of microbial community properties as assessment criteria for rehabilitation success of postmining areas. Currently, there is a need for reference ranges of specific properties in rehabilitated postmining sites to make this approach more practical. The aim of this investigation was to compare assessment parameters indicative of microbial community function (enzymatic assays) and structure (phospholipid fatty acid (PLFA) analysis) in rehabilitated asbestos and coal discard sites and to establish ranges of minimum and maximum values for these parameters in both types of sites. The range established for dehydrogenase activity in coal discard sites was 24.3-339.5 μg INF g −1 2 h −1 and for asbestos 44.5-544.6 μg INF g −1 2 h −1 . Ranges were also established for β-glucosidase, urease, acid phosphatase and alkaline phosphatase. Complete PLFA profiles were determined and ranges established for major PLFA groups and ratios in both types of discard. From the PLFA profiles, viable microbial biomass was determined as 6,080-29,851 and 8,128-47,242 pmol g −1 dry weight for the coal and asbestos discard sites, respectively. While similar ranges were observed for both types of discard, a canonical correspondence analysis that accounts for functional and structural characteristics showed that sites clustered according to the origin of the samples.

Changes in Microbial Community Structure and Soil Biological Properties in Mined Dune Areas During Re-vegetation

“…However, the proportions of GNB tend to increase when stress situations have ceased (Bardgett et al 2001;Romaniuk et al 2011). Other studies also have shown that soil moisture regimes can have great influence on the whole microbial communities (Bardgett et al 1999;Claassens et al 2012;Swallow et al 2009). …”

“…In mined areas, 19:0cy/18:1x7 ratio significantly decreased with time after re-vegetation and with the improvement of soil nutrients (Zhang et al 2012). According to Claassens et al (2012), the increase of 19:0cy/18:1x7 ratio indicates higher levels of stress in coal and asbestos discard areas.…”

“…Microorganisms play fundamental roles that determine productivity and nutrient availability in forest ecosystems, being important in the establishment and maintenance of soils in sustainable ecosystems (Badiane et al 2001;Brockett et al 2012). This makes it necessary to know how microbial communities, their structure, and function change or may indicate changes in functioning of environmental factors (Brockett et al 2012), stress, and/or the restoration process (Claassens et al 2012).…”

“…The correlations between enzyme activities (e.g., phosphatase activity) and microbial groups (e.g., saprophytic fungi and AMF) indicate how changes in MCS could affect soil functions, and consequently, important ecosystem services such as nutrient cycling (Vallejo et al 2012). It is believed that redundancy of functions happens frequently in soils and, due to these functional redundancies, a reduction in any microbial group has little effect on the soil specific functions, since other microorganisms can continue performing the functions (Brockett et al 2012;Claassens et al 2012). …”

“…In addition to affecting soil stability and decreasing its nutrient and organic content, mining promotes significant losses in biodiversity above and below ground (Claassens et al 2012;Izquierdo et al 2005). These disturbances alter the functioning and the structure of microbial communities, energy transfer, nutrient cycling, and the re-establishment of plants (Mummey et al 2002).…”