School of the Environment, Florida A&M University, Tallahassee, FL 32307, USA.
Microb Ecol. 2012 Oct;64(3):738-49. doi: 10.1007/s00248-012-0020-3. Epub 2012 Mar 4.
Microorganisms are very sensitive to environmental change and can be used to gauge anthropogenic impacts and even predict restoration success of degraded environments. Here, we report assessment of bauxite mining activities on soil biogeochemistry and microbial community structure using un-mined and three post-mined sites in Jamaica. The post-mined soils represent a chronosequence, undergoing restoration since 1987, 1997, and 2007. Soils were collected during dry and wet seasons and analyzed for pH, organic matter (OM), total carbon (TC), nitrogen (TN), and phosphorus. The microbial community structure was assessed through quantitative PCR and massively parallel bacterial ribosomal RNA (rRNA) gene sequencing. Edaphic factors and microbial community composition were analyzed using multivariate statistical approaches and revealed a significant, negative impact of mining on soil that persisted even after greater than 20 years of restoration. Seasonal fluctuations contributed to variation in measured soil properties and community composition, but they were minor in comparison to long-term effects of mining. In both seasons, post-mined soils were higher in pH but OM, TC, and TN decreased. Bacterial rRNA gene analyses demonstrated a general decrease in diversity in post-mined soils and up to a 3-log decrease in rRNA gene abundance. Community composition analyses demonstrated that bacteria from the Proteobacteria (α, β, γ, δ), Acidobacteria, and Firmicutes were abundant in all soils. The abundance of Firmicutes was elevated in newer post-mined soils relative to the un-mined soil, and this contrasted a decrease, relative to un-mined soils, in proteobacterial and acidobacterial rRNA gene abundances. Our study indicates long-lasting impacts of mining activities to soil biogeochemical and microbial properties with impending loss in soil productivity.
微生物对环境变化非常敏感，可用于评估人为影响，甚至预测退化环境的恢复成功。在这里，我们报告了使用牙买加未开采和三个开采后的地点评估铝土矿开采活动对土壤生物地球化学和微生物群落结构的影响。开采后的土壤代表了一个时间序列，自 1987 年、1997 年和 2007 年以来一直在恢复中。在旱季和雨季收集土壤，并分析 pH 值、有机质 (OM)、总碳 (TC)、氮 (TN) 和磷。通过定量 PCR 和大规模平行细菌核糖体 RNA (rRNA) 基因测序评估微生物群落结构。使用多元统计方法分析土壤因子和微生物群落组成，结果表明，即使在恢复超过 20 年后，采矿对土壤仍具有显著的负面影响。季节性波动导致测量的土壤性质和群落组成发生变化，但与采矿的长期影响相比，这些变化很小。在两个季节中，开采后的土壤 pH 值较高，但 OM、TC 和 TN 降低。细菌 rRNA 基因分析表明，开采后的土壤多样性普遍降低，rRNA 基因丰度最多降低了 3 个对数级。群落组成分析表明，变形菌门（α、β、γ、δ）、酸杆菌门和厚壁菌门的细菌在所有土壤中都很丰富。与未开采土壤相比，新开采后的土壤中厚壁菌门的丰度升高，而与未开采土壤相比，变形菌门和酸杆菌门 rRNA 基因丰度降低。我们的研究表明，采矿活动对土壤生物地球化学和微生物特性具有持久的影响，土壤生产力即将丧失。
