Ungulate occurrence in forest harvest blocks is influenced by forage availability, surrounding habitat, and silviculture practices

Forest harvesting causes habitat loss and alteration and can change
predator-prey dynamics. In Canada, forest harvesting has shifted the
distribution and abundance of ungulates (deer, elk, and moose) that prefer
early seral forest, resulting in unsustainable caribou predation by shared
predators (bears, cougars, and wolves). Long-term solutions for caribou
recovery require management to reduce ungulate prey species within caribou
ranges. Silviculture practices applied after forest harvesting directly
affect the amount of forage available in harvested areas, and therefore
influence ungulate distribution, but few studies have completed detailed
assessments on how specific treatments of site preparation, planting, and
stand tending influence ungulate use of harvest blocks. We used camera
traps, silviculture data, GIS-derived habitat and disturbance data, and
detailed vegetation data collected at field sites to investigate ungulate
occurrence in harvest blocks in west-central Alberta, Canada. We compared
seasonal ungulate occurrence and investigated how site-specific
characteristics, the surrounding habitat and disturbance density, and
fine-scale silviculture treatments influenced ungulate occurrence in
blocks.  Deer, elk, and moose occurrence was higher in summer
compared to winter. Elk, moose, and white-tailed deer occurrence were
higher in blocks with greater availability of specific forage species.
Moose occurrence was higher in blocks with a lower road density in the
surrounding area, and white-tailed deer occurrence was higher in blocks
further from seismic lines and with a lower proportion of harvest blocks
in the surrounding area. Deer, elk, and moose occurrence were higher in
younger harvest blocks. Mule deer and white-tailed deer occurrence were
lower in blocks with higher planting densities of lodgepole pine, and mule
deer occurrence was also lower in blocks that had been stand-tended. Our
study provides detailed information on ungulate response to fine-scale
silviculture methods used in Alberta, directly linking wildlife occurrence
to forestry practices, and providing practical scientific information to
inform sustainable forestry. Translating this research into practical
landscape management decisions could benefit boreal biodiversity,
including threatened species like caribou, and culturally and economically
important species like deer, elk, and moose.