Role of terrestrial carbon and base cations in the recovery of damaged aquatic systems

清洁的水和多样的水生生物群落如此依赖于流域过程，以至于它们可以被认为是北方盾带健康森林的“产品”。来自陆地流域的碳输入是稀释湖泊生产力的关键决定因素，颗粒碳和溶解碳（DOC）对接收湖泊和溪流的食物网贡献很大。来自森林土壤的碱性阳离子也影响大量的水生过程，包括引入的金属的毒性，但在盾区大部分地区，碱性阳离子呈现出枯竭的现象，而在许多城市地区附近，碱性阳离子呈现出富集的现象。因此，我们需要更好地了解陆地/水生的联系，才能预测各种流域干扰的单一或联合影响，或预测压力源消除后恢复或重新定殖的可能轨迹。加拿大萨德伯里的金属采矿和冶炼综合体周围的流域受到严重影响，这是北方流域多种压力因素长期影响的典型例子。在这里，即使在空气污染控制和广泛的土地复垦工程上投资超过10亿美元，近岸环境中敏感的无脊椎动物物种的恢复仍落后于清理工作几十年。我们的研究结合了空间调查、野外和实验室实验来检测、测量和评估陆地/水生联系对无脊椎动物群落恢复的重要性。我们还在安大略省的研究地点比较和对比了不同干扰类型（林业、火灾、采矿）的影响，并研究了景观和当地栖息地因素在塑造底栖无脊椎动物群落中的作用。我们的研究旨在提高我们对从干扰中恢复的基本过程的理解，并帮助生态风险管理者更有效地设计

Clean water and diverse communities of aquatic biota are so dependent on watershed processes that they can be considered "products" of healthy forests in the Boreal Shield Ecozone. Carbon inputs from the terrestrial watershed are key determinants of productivity of dilute lakes, with both particulate and dissolved (DOC) carbon contributing heavily to the foodwebs of receiving lakes and streams. Base cations from forest soils also affect a vast array of aquatic processes, including the toxicity of introduced metals, but base cations are exhibiting depletions across much of the Shield region, while showing enrichment near many urban areas. Better understanding of terrestrial/aquatic linkages is therefore needed before we can predict the single or combined effects of various watershed disturbances or predict the likely trajectories that recovery or recolonization will take after stressors have been removed. The severely impacted watersheds surrounding the metal mining and smelting complex in Sudbury, Canada are classic examples of the protracted effects of multiple stressors in Boreal watersheds. Here, even after more than $1B investment in air pollution control and extensive land reclamation work, recovery of sensitive species of invertebrates in nearshore environments lags decades behind the cleanup efforts. Our study uses a combination of spatial surveys and field and laboratory experiments to detect, measure and evaluate the importance of terrestrial/aquatic linkages in relation to the recovery of invertebrate communities. We also compare and contrast the effects of different disturbance types (forestry, fire, mining) at study sites across Ontario and examine the role of landscape and local habitat factors in shaping benthic invertebrate communities. Our studies are designed to improve our understanding of the fundamental process of recovery from disturbance and to help ecological risk managers design more effective