Understanding the processes behind Boreal landscape disturbances

虽然生态系统通常具有弹性，但如果超过临界点，由于强大的正反馈机制，生态系统功能将发生灾难性的转变。在北方针叶林内，这不仅会导致生态系统局部的变革性状态转变，而且由于相邻生态系统单元之间的相互作用和反馈，也会导致景观恢复力的丧失。这样的转变可能通过马赛克级联，导致其大规模的景观失败。阿萨巴斯卡油砂的复垦需要建造湖泊、湿地和林地的马赛克景观，这些景观是未受干扰的北方平原的特征。这种景观必须随着时间的推移而发展，以迅速发展广阔的生产性森林，最大限度地发挥景观的经济潜力，同时保持较高的水通量以冲洗生态有害盐。因此，关闭矿山计划必须理解并认识到关闭矿山计划中这种潜在失败的风险，并权衡最小化失败风险的愿望，以及预期生态系统服务的损失，与初始景观建设的经济成本，以及关闭矿山计划所针对的生态系统服务的规模和多样性。通过在西部寒带平原进行的十多年来由工业界资助的研究，水文、生态和干扰方案（HEAD）通过经过处理的实地和模型研究，对景观的生态水文功能形成了详细的概念性理解；这些知识正在为目前的煤矿关闭计划提供信息。该研究表明，气候循环是不同强度和阶段的气候信号的叠加，为这些景观系统的生态水文行为提供了总体驱动力。这个循环通过景观存储单元级联，这些存储单元在配置、范围和连接规模上都有所不同。由此产生的局部水力特征为不同单元的生态风险提供了主要的控制。该项目在此概念基础上发展，利用HEAD研究项目近二十年的研究成果（来自约15000口井和压力表的测量，以及一系列补充的水文、气象和生态数据），对复杂的马赛克景观的生态水文行为进行自上而下的统计分析。为了测试水文，生态和生物地球化学的不同阵列的水力单位如何响应气候周期。确定可能导致生态系统单元失效的潜在条件的风险来源、驱动因素以及复杂的马赛克景观系统中这种局部失效的影响。这些知识将指导未来的矿井闭合设计计划，以及正在进行的基于过程的现场和建模研究。

While ecosystems are generally resilient, if pushed beyond a tipping point, a catastrophic shift in ecosystem function will occur as the result of strong positive feedback mechanisms. Within the boreal, this will result not only in a local transformative state shift in the ecosystem, but also a loss of landscape resilience due to the interactions and feedbacks between adjoined ecosystems units. Such a transition could cascade through the mosaic and lead to its large scale landscape failure. The reclamation of the Athabasca Oil Sands requires the construction of such mosaic landscapes of lakes, wetlands and forestlands that characterize the undisturbed Boreal Plains. Such landscapes must develop over time to rapidly develop expansive productive forests, maximizing the economic potential of the landscape, whilst maintaining high water fluxes to flush ecological harmful salts. Mine closure plans must therefore understanding and recognize the risk of such potential failures in mine closure plans, and weigh the desire to minimize risk of failure, and the loss of desired ecosystem services, against the economic costs of initial landscape construction, and the magnitude and diversity of ecosystem services that are targeted by the mine closure plan. Through over decade of ongoing industry funded research within the western Boreal Plain, the Hydrology, Ecology and Disturbance programme (HEAD) has developed a detailed conceptual understanding of the ecohydrological functioning of the landscape through processed based field and modelling research; knowledge that is informing current mine closure plans. This research has demonstrated that the climate cycle, a superposition of varying climate signals of different intensities and phases, provides the overarching driver of the ecohydrology behavior of these landscape systems. This cycle cascades through landscape storage units that vary in configuration, extent and scale of connectivity. The resulting local hydraulic signature provides the primary control on the ecological risk to the different units over time. This project develops on this conceptual foundation, utilizing the legacy of close to two decade of research activities across the HEAD research programme (measurements from ~15000 wells and piezometers in addition to a range of supplementary hydrological, meteorological and ecological data) to provide a top-down statistical analysis of the ecohydrological behavior of the complex mosaic landscape. To test how the hydrology, ecology and biogeochemistry of the diverse array of hydraulic units respond to the climate cycle. To determine the sources of risk for potential conditions that would likely instigate failure of the ecosystem units, their drivers and the impact such local failures within the complex mosaic landscape system. This knowledge will direct future mine closure design plans, in addition to ongoing process based processes based field and modeling studies.