Diamond Mine Reclamation in the NWT: Substrates, Soil Amendments and Native Plant Community Development

Regions: North Slave Region

Tags: biology, mining impacts, land reclamation, native plants, revegetation

Principal Investigator: Naeth, M. Anne (6)
Licence Number: 14565
Organization: University of Alberta
Licenced Year(s): 2017 2016 2015 2014 2009 2008 2005
Issued: Jul 14, 2009
Project Team: Sarah Wilkinson (Research Coordinator, University of Alberta), Ingrid Hallin (Research Coordinator, University of Alberta), Student Assistants (University of Alberta)

Objective(s): The objectives of this research are to: 1. Native shrub establishment: Determine the effect of season of seeding/planting on shrub establishment and survival; 2. Effect of microtopography: Determine the effect of microsites (boulders, rocks, soil mounds and pockets) on plant emergence and establishment, as well as how they influence soil structure; 3. Effect of stockpiled topsoil: Investigate the effect of stockpiling salvaged topsoil on its potential as a soil amendment and source of native propagules for reclamation of disturbed sites; 4. Investigate the ability of different substrates to retain water and increase cation exchange to facilitate plant growth; 5. Determine the best soil amendments to add nutrients to the soil to promote growth.

Project Description: The objectives of this research are to:
1. Native shrub establishment: Determine the effect of season of seeding/planting on shrub establishment and survival.
2. Effect of microtopography: Determine the effect of microsites (boulders, rocks, soil mounds and pockets) on plant emergence and establishment, as well as how they influence soil structure.
3. Effect of stockpiled topsoil: Investigate the effect of stockpiling salvaged topsoil on its potential as a soil amendment and source of native propagules for reclamation of disturbed sites; stockpiled topsoil may lose nutrients over time and become ineffective for reclamation / revegetation.
4. Investigate the ability of different substrates to retain water and increase cation exchange to facilitate plant growth.
5. Determine the best soil amendments to add nutrients to the soil to promote growth.

Research sites established on 3 blasting pads at the old magazine storage facility were investigated. The smaller pads were divided into 3 plots, the largest pad was divided into 6 plots, and 1 of 3 substrates randomly assigned. Each plot was divided and assigned fresh or stockpiled topsoil, and then divided again crosswise and assigned spring or fall seeding/planting. Microsites sheltered by boulders, soil mounds or soil depressions were established. Substrates were selected based on which had favorable properties and produced the highest plant densities in the first phase of research. The 4 revegetation treatments are shrub cuttings spring collected and planted immediately, fall collected and planted immediately, seeding of shrubs in spring, and seeding of shrubs in fall. Subplots were marked with wooden stakes. Seed from all collection times was mixed.

Local community members currently holding term positions within the Environment Department at Diavik are able to assist the researchers during sampling and field work. Also, discussions during morning meetings about methods and activities allow others to learn about reclamation practices and what they are trying to accomplish.

A summary of research is provided in the Annual Report, provided to EMAB, and research is discussed in annual communities’ updates.

The fieldwork for this study will be conducted from July 13 to October 31, 2009, at the Diavik Diamond Mine, Lac de Gras, NWT.




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