Evaluation of Selected Mechanical Clearings in the Northwest Region in 2002


John Hallett


Mechanically created clearings have been constructed in forested and shrub areas throughout the ACA’s Northwest Region to increase browsing opportunities for ungulates. The purpose of this project was to determine the comparative duration of usage amongst sites, what species preferred each clearing site, and if certain vegetation types were better candidates for clearing. Successful sites would be those with more browse (stems/ha) and or more ungulate usage (pellet groups/ha) than that observed in control (uncleared) areas. Plots were established within clearings and the relative amount, species, heights, and browsing of each species was tallied. An estimate of the number of ungulate pellet groups per hectare for each surveyed clearing was also tallied, although this was not done at some sites due to late snowpacks.

Results found that there were more moose pellets (groups/ha) and generally less deer pellets in the clearings than control areas. No clear trend emerged for elk due to relative scarcity of elk pellets in the surveyed areas. Clearings generated more stem/ha of browse than in control areas, but the amount of browsing (# of browsed stems/ha) was not consistently higher in clearings than in control areas. Factors such as browse preference and height of re-growth (in aspen) were factors in the degree of browse usage. Areas cleared in decadent willow did not result in increased browse than that observed in control areas.

It is recommended that clearing decadent willow sites be avoided, and if moose densities are high, clear larger and/or more numerous areas. Clearings should be done in aspen since this results in predictably good browse production, providing the aspen was healthy and the clearings are sufficiently large.

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