资源型城市采煤沉陷区不同人工植被对土壤养分、酶活性及有机碳库组分的影响——以安徽省淮南市为例

Effects of different artificial vegetation on soil nutrients,enzyme activities and organic carbon poolcomponents in coal mining subsidence areas ofresource-depleted cities: A case studyofHuainan City,Anhui Province

摘要:

【目的】 探讨淮南采煤沉陷区种植不同人工植被下土壤养分、酶活性及有机碳库组分的含量，为该地区选择适宜的人工植被类型、改善矿区复垦土壤质量提供参考。【方法】 选取未改造地、人工草地、石楠林地、水杉林地、刺槐林地、刺槐-侧柏混交林地6 种人工类型样地为研究对象，研究土壤养分、酶活性及有机碳库组分含量差异及相关性。【结果】 种植人工植被有效降低了土壤pH 值；人工植被地的土壤有机质、全氮、碱解氮、全磷、有效磷含量均显著高于未改造地，而全钾及速效钾含量低于未改造地。除过氧化氢酶以外，其余4 种酶活性在未改造地中均处于最低水平。刺槐-侧柏混交林土壤脲酶、多酚氧化酶、蔗糖酶含量均高于其他人工植被。不同类型人工植被土壤酶活性之间也存在着显著差异。除过氧化氢酶以外，其余4 种酶活性与土壤养分之间相关性显著。各人工植被均不同程度提高了土壤有机碳库各组分含量，刺槐-侧柏混交林的总有机碳量与可溶性有机碳量均高于其余5 种类型样地，刺槐林土壤易氧化有机碳的含量在所有类型样地中达到最高水平，水杉林土壤微生物量碳的含量在在所有类型样地中达到最高水平。相关性分析结果表明，土壤有机碳库组分含量与土壤酶活性之间存在显著相关性。冗余分析结果表明，土壤有机质、全氮、全钾、速效钾是土壤酶活性重要的影响因子，能解释酶活性变异的66. 04%。【结论】 种植人工植被改善了复垦矿区土壤质量，提高了土壤有机碳库组分的含量。土壤酶活性显著影响土壤养分及有机碳库，可以用来表征淮南采煤沉陷区土壤肥力质量及有机碳固持能力。刺槐-侧柏人工混交林模式对土壤肥力、固碳能力提升效果更显著，对矿区土壤整体质量和生态环境有明显的改良作用。

Abstract:

【Objective】 The effects of different artificial vegetation on soil nutrients，enzyme activity and organiccarbon pool components in Huainan coal mining subsidence areawere investigated to provide references for selectingsuitable vegetation types and improving soil quality in mine reclamation in this area.【Method】 Six artificial types ofsample plots，namely unmodified land （bare land），artificial grassland，heathland，Metasequoia woodland，acaciawoodland and acacia-sidebark mixed woodland，were selected to study the differences and correlations of soil nutrients，enzyme activities and organic carbon pool components.【Result】 The experiments showed the followingresults.Planting artificial vegetation effectively reduced the soil pH value. The contents of soil organic matter，total nitrogen，alkaline nitrogen，total phosphorus，and available phosphorus in artificial vegetation land were significantly higher thanthose in unmodified land，while the contents of total potassium and available potassium were lower than those in unmodifiedland. Except for catalase，the activities of the other four enzymes were at the lowest level in the unmodifiedland. The soil urease，polyphenol oxidase，and sucrase contents in the mixed forest of Robinia pseudoacacia and Platycladusorientaliswere higher than those of other artificial vegetation. There were also significant differences in soil enzymeactivities among different types of artificial vegetation. Except for catalase，there was a significant correlation betweenthe activities of the other four enzymes and soil nutrients. Each artificial vegetation increased the content ofeach component of soil organic carbon pool to varying degrees. The Total organic carbon and soluble organic carbonof the mixed Robinia-Platycladus forest were higher than those of the other five types of sample plots. The contentof soil readily oxidized organic carbon of Robinia pseudoacacia forest reached the highest level in all types of sampleplots，and the content of soil microbial biomass carbon of Metasequoia glyptostroboides forest reached the highestlevel in all types of sample plots. The correlation analysis results indicated that there was a significant correlation betweenthe content of soil organic carbon pool components and soil enzyme activity. The results of redundancy analysisshowed that soil organic matter，total nitrogen，total potassium，and available potassium were important influencingfactors for soil enzyme activity，accounting for 66. 04% of the variation in enzyme activity.【Conclusion】 Artificialvegetation improved soil quality and increased the content of soil organic carbon pool components in reclaimed miningareas. Soil enzyme activity significantly affected soil nutrients and organic carbon pool，which could be used to characterizethe quality of soil fertility and the ability of organic carbon fixation in Huainan coal mining subsidence area. Theartificial mixed forest model of Robinia pseudoacacia and Platycladusorientalis had a more significant effect on improvingsoil fertility and carbon fixation capacity，and had a significant improvement effect on the overall quality of soil andecological environment in the mining area.