Abstract

Sudbury, Ontario, Canada experienced severe environmental degradation from intensive logging, mining, and smelting activities. Acidification and erosion of soils, as well as heavy metal deposition led to widespread vegetation mortality and the creation of 20 000 ha of barren and 80 000 ha of semi-barren land within the Sudbury region. Restoration processes, consisting of limestone application, fertilization, seeding, and tree planting, was initiated in 1978 and continues to present day. Although initial assessments made immediately following restoration predicted a stable, self-sustaining vegetation community would develop, no formal monitoring protocol was initiated. In this study, we describe the state of four restored sites (3 barren, 1 semi-barren), and their naturally recovering (untreated) analogues, within the Sudbury technogenic barrens 25 to 30 years post-restoration. At each site, two belt transects were established in the restored and untreated areas within which soil pH, tree height and diameter, and ground cover of vegetation identified to species were assessed. Soil pits were excavated to examine pedological development. Soils were Dystric Brunisols in all sites. In restored areas, soil pH and humus layer thickness were generally greater than in areas left to recover naturally. Elevated pH through the soil profile at treated sites indicate limestone application effectively reduced acidity and was sustained up to 30 years post-application. In untreated areas, moss and lichen were abundant, and although vascular plant cover was greater in restored areas, vegetation communities are still significantly different from the reference site. Adequate cover of native understory species was not obtained in any of the treated areas. Results indicate that aerial application of limestone, fertilizer, and seed is less effective than ground application, especially in areas with a high proportion of exposed bedrock. Active restoration has been beneficial to the recovery of the Sudbury technogenic barrens. Continued monitoring will be essential to facilitate the development of a self-sustaining vegetation community.

中文翻译：

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萨德伯里科技贫瘠之地 30 年恢复后的生态系统恢复

摘要

加拿大安大略省萨德伯里因密集的伐木、采矿和冶炼活动而经历了严重的环境退化。土壤酸化和侵蚀以及重金属沉积导致广泛的植被死亡，并在萨德伯里地区创造了 20 000 公顷的贫瘠土地和 80 000 公顷的半贫瘠土地。恢复过程包括石灰石施肥、施肥、播种和植树，始于 1978 年，一直持续到今天。尽管在恢复后立即进行的初步评估预测将发展一个稳定的、自我维持的植被群落，但没有启动正式的监测协议。在这项研究中，我们描述了四个恢复场地（3 个荒地，1 个半荒地）及其自然恢复（未处理）类似物的状态，在恢复后 25 至 30 年的萨德伯里技术贫瘠之地内。在每个地点，在恢复和未处理区域建立了两个带样带，在这些区域内评估土壤 pH 值、树高和直径以及确定为物种的植被的地面覆盖。挖掘土壤坑以检查土壤发育。所有地点的土壤都是 Dystric Brunisol。在恢复区域，土壤 pH 值和腐殖质层厚度通常大于自然恢复区域。通过处理地点的土壤剖面升高的 pH 值表明石灰石的施用有效地降低了酸度，并且在施用后可持续长达 30 年。在未经处理的地区，苔藓和地衣丰富，虽然恢复地区的维管植物覆盖率更高，但植被群落与参考地点仍有显着差异。在任何处理区域都没有获得足够的本地林下物种覆盖。结果表明，石灰石、肥料和种子的空中施用不如地面施用有效，尤其是在裸露基岩比例较高的地区。主动恢复有利于萨德伯里技术性贫瘠地区的恢复。持续监测对于促进自我维持的植被群落的发展至关重要。