Tundra restoration: Niche construction in early successional plant-soil crust

目前，在加拿大北部运营的许多行业都面临着恢复受资源开采活动影响的苔原生态系统的需要。我们与Agnico Eagle Mines Ltd （AEM）合作，旨在开发可应用于Meliadine高级金矿项目的陆地冻土带恢复技术。过去的矿产勘探钻探和拟议的作业已经并将影响努纳武特Meliadine的冻土带环境。由于该地区有3000多个钻探点，预计还会有更多的钻探和矿场开发，因此迫切需要针对具体地点的冻土带恢复技术。播种和施肥是许多植被恢复工作中常用的方法。然而，这种方法在北部冻土带环境中的生态和经济可行性受到限制，因为缺乏北部原生冻土带植被的商业种子库存和孤立的站点位置。为了建立自然演替轨迹并促进关键的生态系统过程，我们将开发仅依赖于现场可用材料的恢复技术。具体来说，我们将研究当地生物土壤结皮（BSCs，即苔藓植物、地衣、蓝藻、细菌、真菌和古细菌等群落）和冻土带表层有机层（即活性层的上部，包括所有种子库和根茎物质）的潜力，以促进干扰前北极群落组合的发展和基本生态系统功能的恢复。用这些当地材料成功恢复北方环境需要更好地了解可用繁殖体的初始和实现再生生态位。在这里，我们认为初始生态位是基础物种首先在受干扰的地点建立时遇到的第一个非生物和生物条件。在初始建立之后，这些物种将改变环境中的非生物和生物成分，从而构建实现的生态位。提高我们对早期生态位构建的认识将有助于改进现有的北极冻土带演替模型，并促进在恢复过程中有效利用原生冻土带物种。

Currently many industries operating in northern Canada are faced with the need to restore tundra ecosystems that have been impacted by resource extraction activities. Working in partnership with Agnico Eagle Mines Ltd (AEM) we aim to develop terrestrial tundra restoration techniques that can be applied at the Meliadine advanced-stage gold project. Both past mineral exploration drilling and proposed operations have and will impact the tundra environment at Meliadine, Nunavut. With over 3000 drilling sites in the regional area and further drilling and mine site development expected, there is a strong need for site-specific tundra restoration techniques. Seeding and fertilization is commonly used in many revegetation efforts. However, the ecological and economic feasibility of this approach in northern tundra environments is limited due to the lack of commercial seed stocks for northern native tundra vegetation and isolated site locations. To establish natural successional trajectories and promote key ecosystem processes, we will develop restoration techniques reliant only on materials available on-site. Specifically, we will examine the potential for local Biological Soil Crusts (BSCs i.e. communities of bryophytes, lichens, cyanobacteria, bacteria, fungi and archaea etc.) and tundra surface organic layers (i.e. the upper section of the active layer including all seed bank and rhizomatous materials) to foster the development of pre-disturbance arctic community assemblages and recovery of essential ecosystem functions. Successful restoration of northern environments with these local materials requires a better understanding of both the initial and realized regenerative niche of available propagules. Here we consider the initial niche the first abiotic and biotic conditions encountered by foundational species that are first to establish on a disturbed site. Following initial establishment, these species will modify abiotic and biotic components in the environment and thereby construct the realized niche. Improving our understanding of early niche construction will help to improve current models of arctic tundra succession and facilitate effective use of native tundra species in restoration.