Habitat use and ecologically sustainable carrying capacity for elk (Cervus elaphus) in the Takhini Valley, Yukon
Dates
Year
2010
Citation
Chambers, Jesse Helen Sarah, 2010, Habitat use and ecologically sustainable carrying capacity for elk (Cervus elaphus) in the Takhini Valley, Yukon: University of Calgary (Canada).
Summary
Population growth of a (re)introduced elk (Cervus elaphus ) herd (n = 144) in the Takhini Valley, southwest Yukon, has increased the need to determine an ecologically sustainable carrying capacity for the primary range. Elk telemetry data, aerial photographs, and contour maps were used to define the study area (95 km2 ), which represented 56% of the total local range used in 2007 and 2008. Plot sampling, plant community classification, and air-photo mapping were used to determine the composition and areal extent of vegetation types, each of which was used to evaluate forage availability. Seven treed and five nontreed types were recognized, with treed forest types representing 68% of the area. Nontreed vegetation produced more forage [...]
Summary
Population growth of a (re)introduced elk (Cervus elaphus ) herd (n = 144) in the Takhini Valley, southwest Yukon, has increased the need to determine an ecologically sustainable carrying capacity for the primary range. Elk telemetry data, aerial photographs, and contour maps were used to define the study area (95 km2 ), which represented 56% of the total local range used in 2007 and 2008. Plot sampling, plant community classification, and air-photo mapping were used to determine the composition and areal extent of vegetation types, each of which was used to evaluate forage availability. Seven treed and five nontreed types were recognized, with treed forest types representing 68% of the area. Nontreed vegetation produced more forage (279-652 kg/ha) than all treed types, except Populus tremuloides/Rosa acicularis-Arctostaphylos uva-ursi vegetation (438 kg/ha), which was the second-most common type in study area (15% of area). No significant differences (P ≤0.05) were found between crude protein amounts among vegetation types, though graminoids were lower in crude protein than either forbs or shrubs ( P ≤0.001). Different carrying capacity scenarios were developed based on cumulative assumptions. These included considerations of forage quantity, availability and preference, horse (Equus ferus caballus ) and mule deer (Odocoileus hemionus ) requirements, and diet similarities with elk. Winter was the most limiting season because forage was senesced. The most conservative scenario included ecologically sustainable safe-use factors, and resulted in an estimated winter carrying capacity of 72-144 elk for the study area. The assessment of carrying capacity was most sensitive to browse consumption and competition with horses. These factors require further investigation to refine the estimated ecologically sustainable carrying capacity. Keywords: Cervus elaphus , ecologically sustainable carrying capacity, elk, forage, range ecology and management, Yukon.
