| Summary: | A random sample of forty high altitude block vertical aerial
photographs was drawn from two extensive districts of the south
Cariboo region of British Columbia. The five hundred square
miles of sample area so obtained was cover-typed through
interpretation of the aerial photographs. Both mature and seral
forest stages constituting moose habitat were identified
primarily through the use of criteria which permitted the
recognition of individual tree species and secondarily through
the recognition of characteristics peculiar to the aspect of each
forest type when viewed as a unit. Stereoscoptic examination
permitted delimination of the types on the aerial photographs.
Planimetric measurement of these areas followed. Sub—sampling of
these areas resulted in the establishment of sixty—four
permanent plots. Twelve thousand feet of line-interception
transect data were obtained from the plots. Browse species were
classified both for amount of available food and for degree of
utilization by moose. Availability was largely determined by
standards derived from shrub height and D.B.H., while utilization
was categorized into four degrees on the basis of the amounts or
the previous years twigs that had been removed from the shrub by
the browsing of moose. Analysis of the ground shrub and tree
layers resulted in distinctive floral compositions being
obtained for seven forest types which constitute moose habitat.
Characteristic intensities of browse utilization were also
evident in each forest type—the more dense, mature forests
receiving heavier usage than the open forest stands.
Index ratings were established both for the density of
available browse and for the degree or utilization of browse in
each of the seven forest types, Application of these indices to
the areas of each forest type indicated relative food
productivity and usage of browse in the two sample districts.
With the establishment of the indices, moose ranges in the
remainder of the sample district may be assessed solely from
aerial photographs thereby eliminating extensive ground survey,
Extension of this method to other forest areas will permit
similar assessment of moose habitat in these regions, once any
new forest types are identified and valuated through limited
ground subsampling.
Severe browsing of unpalatable species, not generally
consumed, indicated overuse of many moose winter ranges.
Controlled burning of certain severely overbrowsed ranges and
further reductions in the moose population through either-sex
seasons are suggested. === Science, Faculty of === Zoology, Department of === Graduate
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