Brenda Mine: Biodiversity Enhancement

Interior British Columbia · 2011 program and 2012–2016 follow-up

Dense grass and legume cover, compacted ground and browsing limited the establishment of shrubs and trees at Brenda Mine.

Polster Environmental Services provided senior review and direction of vegetation biodiversity enhancements within a team with Altura Environmental Consulting and Bearfoot Resources, as documented in the 2011 annual report.

The program combined selected rough and loose treatment patches, live cuttings, browsing protection and habitat structures. Photographs from 2012–2016 show developing woody vegetation in treated areas.

Explore the treatments, follow-up observations and original presentation below.

Discuss mine reclamation with PES

Seeded grasses and legumes can establish quickly on disturbed mine ground. At Brenda, dense cover also competed with the woody plants needed to develop a more diverse plant community.

Conditions varied across the reclaimed mine. Coarse, compacted surfaces offered few sheltered places for seedlings, while browsing damaged emerging shrubs. Addressing these constraints required ground preparation and protection as well as planting.

David Polster used the term biological desert to describe reclaimed areas with green cover but little habitat diversity. The biodiversity program sought to add the shrubs, trees and habitat features missing from these areas.

The treatment program addressed four related constraints:

Dense grass and legume cover. Established ground cover competed with young woody plants.

Compacted surfaces. Smooth, heavily tracked ground offered few sheltered places for seedlings to establish.

Limited habitat structure. Uniform grass cover lacked the brush piles, standing wood and varied vegetation used by wildlife.

Browsing. Deer, elk and moose could damage new growth and slow shrub establishment.

Rough and loose surface treatment created planting sites within selected areas of the reclaimed mine.

An excavator broke up compacted ground to form mounds and hollows, with woody debris distributed across the surface. This created a range of sheltered, exposed, wetter and drier positions for plants.

The 2011 biodiversity plan proposed roughly 10% patch coverage. Scattered treatment patches were intended to create edge habitat and places from which woody vegetation could develop. This was a planning target for the Brenda program.

The surface preparation supported establishment in several ways:

• Varied moisture conditions. Hollows can retain water while raised ground drains more freely.
• Seed capture. Irregular surfaces can catch seeds and organic material.
• Sheltered planting sites. Mounds and hollows provide small areas where seedlings can establish.
• Access for live staking. Loosened material allows cuttings to be installed deeply where compacted ground would make installation difficult.

Treating separate patches over several years also created areas at different stages of vegetation development, adding variety across the mine.

The photographs show the ground conditions, surface preparation and developing plants. Wildlife photographs illustrate the browsing and habitat considerations discussed in the original presentation.

Sparse vegetation on coarse mine material.

Cuttings growing among treated mounds and hollows, August 9, 2012.

A deer illustrates browsing pressure on emerging shrubs.

Live cuttings were installed after surface preparation. Alder, discussed separately in the Brenda presentation, contributed a different function as a nitrogen-fixing pioneer tree.

Alder forms a relationship with nitrogen-fixing bacteria in its roots. This can help it establish on nutrient-poor ground and contribute nitrogen and organic matter as vegetation develops.

Deeply installed cuttings and small transplant plugs make use of different planting positions. Species and planting methods need to match the ground conditions and available moisture.

Habitat features complemented the surface treatment and planting:

Brush piles retained woody material on the site and provided cover for birds and small mammals.

Fencing protected emerging woody vegetation from browsing. The 2011 program report also identified maintenance needs during establishment.

Nest boxes, including Mountain Bluebird boxes, provided nesting opportunities while young vegetation developed.

David Polster described the public value of the wildlife observations: "The value of a photo like this [Mountain Bluebirds] in the local paper compared to a photo of the Mount Polley Tailings disaster cannot be calculated."

Bat boxes and a Kestrel box added further habitat features to the site.

Dated photographs record plant establishment and wildlife observations during the follow-up period:

June 5, 2012: Cuttings starting to grow and Mountain Bluebirds observed at nest boxes.

August 9, 2012: Growth from cuttings among mounds, hollows and woody material.

May 13, 2013: A further visit documenting vegetation development.

May 18, 2015: Woody growth on coarse mine substrate.

September 20, 2016: Established woody vegetation on treated waste rock.

These observations show developing woody cover in treated areas. The photographs span different treatment areas and viewpoints; their captions identify the available dates and context.

Browsing wildlife, July 13, 2005. The original presentation uses this photograph to explain browsing pressure.

Alder foliage and cones, illustrating a pioneering tree species.

For mine operators and environmental managers, Brenda highlights the need to plan establishment and follow-up together:

Locate treatments carefully. Match patch size and distribution to ground conditions, access and the intended plant community.

Include habitat. Consider how brush piles, standing wood and nesting features can support wildlife while vegetation develops.

Plan for woody plants. Shrubs and trees add vegetation structure and shade as they establish.

Follow establishment. Check plant growth, competition, browsing and maintenance needs as well as total vegetation cover.

PES assesses ground conditions, vegetation and browsing pressure to help plan reclamation treatments and follow-up work.