impacts of the herbicide glyphosate on moose browse and moose use of four paired treated-control cutovers near thunder bay, ontario
abstract
re-assessment of the aerial and ground observations on
four paired, glyphosate treated and control, cutovers near
thunder bay, ontario, indicated that aerial tending with
glyphosate altered the use of these cutovers by moose.
the number of pellet groups favoured the control areas (p
< 0.05) by 1.5 times. additionally, the number of moose
tracks and moose track aggregates were more prevalent (p <
0.05) on the controls for 2 to 3 years after treatment. pre
spray data on 2 areas suggested use shifted away from
glyphosate treated areas.
browse availability was significantly greater (p < 0.05)
on the control plots by 18 times in the highest height class
measured (201 - 350 cm) , 5 times in the next highest (101 -
200 cm) but not statistically significant (p > 0.05) in the
lowest (51 - 100 cm), 2 years after treatment. due to too few
replications, differences in availability 1 year after
treatment were not statistically significant.
biomass of browse removed by moose was 3 to 7 times
greater on controls but again these differences were not
statistically significant.
the average length of moose trails observed in the snow
was shorter (p < 0.05) on the controls suggesting less travel
time. the size (area) of moose track aggregates was the same
(p > 0.05) between treatments indicating equal search time
while browsing.
a carrying capacity model indicated that if all cutovers
were sprayed, the treatment would have a negative impact on
moose densities.
glyphosate treatments should be dispersed to create a
mosaic of glyphosate treated areas next to non-treated areas.
similarily, areas of seasonal importance such as aquatics,
salt licks, and calving areas should have at least a non-sprayed
buffer beside them if the adjacent cut area must be
treated with glyphosate.
collections
- retrospective theses [1604]