Degraded land (formerly ‘reclaimed’) after surface-coal-mining is a serious problem in South Wales. This project uses forestation to foster soil development on opencast coal-mine spoil technosols. It compares records of humification and the soil microbiological system (microcoenosis) using paired data from the same plantings in 1998 and 2018. Statistical analysis finds no significant difference between samples collected under trees planted by the pit-planting versus trench planting method or trees planted using organic or mineral fertilizer. However, there are strong significant differences in both soil organic matter and microflora components and significant correlations with time since tree planting. Most components of the soil organic carbon (TOC) and the microflora increase, often significantly. However, compared to 2018, 1998 samples contain significantly greater maximum levels of Insoluble Carbon while the microflora had significantly more Ammonifying bacteria. Decreases in Insoluble Carbon explain the relatively small increase in TOC between 1998 and 2018. The % extracted with 0.1 N H₂SO₄ is significantly larger in 2018, suggesting active weathering. Similarly, both the maxima and minima of total Humic and Fulvic acids content, extracted with 0.1 M Na₄P₂O₇ + 0.1 M NaOH, are significantly greater in 2018. Total microflora shows significant positive correlations with time-since-tree-planting as do the proportions of bacilli and actinomycetes but the correlation with ammonifying bacteria is negative. In 1998, the microflora was dominated by non-spore-forming bacteria while, in 2018, bacilli and actinomycetes prevail; both are involved in the transformation of complex organic compounds and humification. This indicates active transformation of more complex organic compounds and advancing humification. In sum, forestation of these degraded, formerly reclaimed, opencast coal-mine spoils has resulted in a massive increase in both the size and functioning of the soil organic system.

在南威尔士，露天煤矿开采后的土地退化（以前是“开垦”）是一个严重的问题。该项目利用造林促进露天煤矿弃渣技术的发展。它使用1998年和2018年同一种植的成对数据比较了腐殖化和土壤微生物系统的记录。统计分析发现，采用坑式种植与沟槽种植的树木或使用人工种植的树木采集的样品之间没有显着差异。有机或矿物肥料。然而，自植树以来，土壤有机质和微生物区系成分均存在很大的显着差异，并且与时间的相关性也很明显。土壤有机碳（TOC）和微生物区系的大多数成分通常会显着增加。但是，与2018年相比，1998年的样本中最大不溶碳含量最高，而微生物区系的氨化细菌则更多。不溶碳的减少解释了1998年至2018年之间TOC的相对较小的增长。用0.1 NH提取的百分比₂ SO ₄在2018年显着增加，表明天气活跃。同样，用0.1 M Na ₄ P ₂ O ₇提取的总腐殖酸和黄腐酸含量的最大值和最小值 + 0.1 M NaOH在2018年显着增加。总的菌群与种植时间树和细菌和放线菌的比例呈显着正相关，但与氨化细菌的呈负相关。1998年，微生物区系以非孢子形成细菌为主导，而在2018年，细菌和放线菌占据了上风。两者都参与复杂有机化合物的转化和腐殖化。这表明了更复杂的有机化合物的主动转化并正在促进腐殖化。总而言之，对这些退化的，以前被回收的露天矿渣的森林造林导致土壤有机系统的大小和功能的大量增加。