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

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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.