Abstract: There have recently been many changes in the way mining exploration projects operate, including new technologies, new exploration targets and new environmental regulations. Following recent amendments, to the Yukon Quartz and Placer Mining Acts, a significant new piece of legislation came into effect in December, 1999. The Yukon Quartz Mining Land Use Regulations, administered by the Department of Indian Affairs and Northern Development, now requires the reclamation of disturbed land on mining claims. But what happens at these reclaimed sites several years after the work is finished? Is there more than one way to successfully reclaim such land? How do local conditions affect the regrowth of plants on these sites and how much preparation of the reclaimed surface is needed? This report may not provide answers to all these questions, but it presents data collected at several Yukon sites, each with different ages and having had different reclamation treatments. From these observations, patterns on the success or failure of revegetation programs emerge and provide information on the rate and extent of natural revegetation at reclaimed mining trenches.

Several types of reclamation sites were looked at in several different areas of Yukon, both above and below the treeline. Three of these were exploration trenches that were backfilled and revegetated as part of an experimental reclamation program in 1995. These reclaimed exploration sites included the Red Ridge trench, near Annie Lake in the Whitehorse area, the Nucleus trench, west of Carmacks and the Hawk trench near Dawson City. Each of these reclaimed trenches were revegetated with different seed and fertilizer mixes. This report summarizes how these sites looked in 1999, four years after the reclamation work was done.

At Division Mountain, west of Braeburn, several coal trenches and drill pads were reclaimed by a mineral exploration company between 1995 and 1997. These sites were also looked at in 1999 in order to measure the success of the revegetation program. The last place visited in 1999 was Jason Knoll near Macmillan Pass where a number of exploration trenches and drill pads were reclaimed in the early 1980s. This site provides a look at the longer-term success rate of a revegetation program near the treeline.

Refilled and contoured trenches, with rough and loose surfaces seem to revegetate well. The replacement of original soil is most important and makes the most significant contribution to the revegetation process, particularly at high elevation sites or sites in extreme climatic conditions. The replacement of tree debris significantly improves habitat conditions for small mammals by decreasing access and visibility for predators.

Authors: Mougeot GeoAnalysis and Stu Withers

Map Scale: 1 : 0

NTS Mapsheet(s): 115H08, 115I06, 115O14, 105D06, 105E05

Citation: Mougeot GeoAnalysis and Stu Withers, 2000. Assessment of Long-Term Vegetation and Site Conditions at Reclaimed Yukon Mineral Exploration Sites. Mining & Petroleum Environment Research Group, 2000-2.

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