Ossanna Lia Q R, Serrano Karen, Jennings Lydia L, Dillon Jesse, Maier Raina M, Neilson Julia W
Environmental Science Department, University of Arizona, Tucson, AZ, 85721, USA.
Cedar Creek Associates, Inc., Fort Collins, CO, 80527, USA.
Appl Soil Ecol. 2023 Jun;186. doi: 10.1016/j.apsoil.2023.104813. Epub 2023 Jan 31.
Critical to the environmental sustainability of hard rock mining is the reclamation of disturbed lands following mine closure through revegetation. Improved understanding of associations between above- and belowground processes that characterize successful plant establishment is critical to the implementation of more efficient revegetation strategies for nutrient-poor mine waste materials. The specific objective of this five-year temporal study was to identify progressive biotic and abiotic indicators of primary soil development on mine waste rock (WR) on a slope hydroseeded with native plant species and to quantify comparative effects of plant lifeform on soil development. Aboveground plant diversity and belowground substrate properties were measured annually at 67 m intervals along transects following the slope contour. Seeded WR was compared to unseeded WR and the adjacent native ecosystem. A temporal increase in WR microbial biomass was observed in seeded WR relative to unseeded areas. Microbial community analysis found the unseeded WR to be defined by oligotrophic microbes, whereas targeted grass and shrub root zones samples demonstrated significant increases in specific cellulose and lignin degrading and N-cycling phylotypes. More extensive chemical and biological fertility development was observed in shrub root zones relative to grass. Ten chemical and biological indicators increased significantly in shrub WR relative to unseeded WR, whereas grass WR was only enriched in bacterial 16S rRNA gene copy number/g substrate and bacterial/archaeal and fungal diversity. In addition, the shrub root zone had significantly higher nitrogen-cycling potential than grass root zones or unseeded WR. Thus, both grasses and shrubs improve belowground WR development; however, shrub establishment had greater fertility outcomes. Concurrent belowground fertility development is critical to sustainable plant establishment. Coupled evaluation of above- and belowground metrics provides an improved quantitative assessment of revegetation progress and a valuable tool to guide management decisions.
硬岩采矿的环境可持续性的关键在于，在矿山关闭后通过植被恢复来复垦受干扰的土地。更好地理解表征成功植物定植的地上和地下过程之间的关联，对于实施更有效的贫营养矿山废料植被恢复策略至关重要。这项为期五年的时间研究的具体目标是，确定在播种了本地植物物种的斜坡上，矿山废石（WR）上原生土壤发育的渐进生物和非生物指标，并量化植物生活型对土壤发育的比较影响。沿着与斜坡等高线平行的样带，每隔67米每年测量一次地上植物多样性和地下基质特性。将播种了植物的WR与未播种的WR以及相邻的原生生态系统进行比较。相对于未播种区域，在播种了植物的WR中观察到WR微生物生物量随时间增加。微生物群落分析发现，未播种的WR由贫营养微生物界定，而目标草和灌木根区样本显示，特定纤维素和木质素降解及氮循环系统型显著增加。相对于草，在灌木根区观察到更广泛的化学和生物肥力发展。与未播种的WR相比，灌木WR中有10种化学和生物指标显著增加，而草WR仅在细菌16S rRNA基因拷贝数/克基质以及细菌/古菌和真菌多样性方面有所富集。此外，灌木根区的氮循环潜力明显高于草的根区或未播种的WR。因此，草和灌木都能改善地下WR发育；然而，灌木定植产生的肥力效果更好。同时进行地下肥力发展对于可持续植物定植至关重要。对地上和地下指标的综合评估，能改进对植被恢复进展的定量评估，并为指导管理决策提供有价值的工具。
