Succession of Bacterial Community Structure and Diversity in Soil along a Chronosequence of Reclamation and Re-Vegetation on Coal Mine Spoils in China

Abstract

The growing concern about the effectiveness of reclamation strategies has motivated the evaluation of soil properties following reclamation. Recovery of belowground microbial community is important for reclamation success, however, the response of soil bacterial communities to reclamation has not been well understood. In this study, PCR-based 454 pyrosequencing was applied to compare bacterial communities in undisturbed soils with those in reclaimed soils using chronosequences ranging in time following reclamation from 1 to 20 year. Bacteria from the Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, Planctomycetes and Bacteroidetes were abundant in all soils, while the composition of predominant phyla differed greatly across all sites. Long-term reclamation strongly affected microbial community structure and diversity. Initial effects of reclamation resulted in significant declines in bacterial diversity indices in younger reclaimed sites (1, 8-year-old) compared to the undisturbed site. However, bacterial diversity indices tended to be higher in older reclaimed sites (15, 20-year-old) as recovery time increased, and were more similar to predisturbance levels nearly 20 years after reclamation. Bacterial communities are highly responsive to soil physicochemical properties (pH, soil organic matter, Total N and P), in terms of both their diversity and community composition. Our results suggest that the response of soil microorganisms to reclamation is likely governed by soil characteristics and, indirectly, by the effects of vegetation restoration. Mixture sowing of gramineae and leguminosae herbage largely promoted soil geochemical conditions and bacterial diversity that recovered to those of undisturbed soil, representing an adequate solution for soil remediation and sustainable utilization for agriculture. These results confirm the positive impacts of reclamation and vegetation restoration on soil microbial diversity and suggest that the most important phase of microbial community recovery occurs between 15 and 20 years after reclamation.

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

“…In our study, there was a demonstrable trend toward the nonmined condition with time, for all attributes except P, but the projected time to reach this condition ranged from 16 to 36 years. This recovery trend is generally consistent with that reported for physicochemical properties in other postmining chronosequences (Sourkova et al ; Banning et al ; Claassens et al ; Urbanova et al ; Li et al ). In particular, the consistency in recovery period for TC (36 years) between this and other studies (Sourkova et al ; Acton et al ) could have significant compliance implications for mine managers in Queensland, who are often committed to restoring the predisturbance ecosystem conditions within the tenure of a mining land lease, which is often less than 30 years (Ngugi & Neldner ).…”

“…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 ).…”

“…Recovery of dehydrogenase activity in reclaimed soils, e.g. has been reported to take 2-4 years to reach levels comparable with nonmined sites (Harris & Birch 1989), while microbial community structure takes 5-21 years (Jasper 2007;Lewis et al 2010;Banning et al 2011;Dangi et al 2011;Urbanova et al 2011;Li et al 2014) or more (i.e. >30 years) (Fichtner et al 2014;Zhang et al 2016).…”

Introduced plants as novel Anthropocene habitats for insects

“…the last glacial maximum to present day, and successional timescales e.g. a century following forest clearing for agriculture—Brändle et al, ; Cramer et al, ; Kennedy & Southwood, ; Li et al, ; Nichols & Nichols, ). The specific date of introduction was not significant for the analysis of neophytes in the DBIF data, although the lack of an effect of time on shorter time scales (e.g.…”

Physicochemical and microbiological assessment of soil quality on a chronosequence of a mine reclamation site

“…The abundances, number of OTUs and taxonomic diversity of bacteria, archaea and fungi developed progressively with reclamation ( Figures 6 and 7). Li et al (2014) showed that long-term reclamation greatly improved soil bacterial abundance and diversity. Mukhopadhyay et al (2014) showed an increase in microbial biomass with the age of reclamation.…”