ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

STAPHYLINIDAE
As one might expect, population changes for staphyl inids (rove beet1 es) were
considerably different than for the ground beetles. In 1975, rove beetle populations
in the undisturbed forest, treatment 6, were significantly higher than in any of the
treatments (figure 6, top). Among the treatments, populations in the cl earcut where
residues were mechanical l y removed (treatment 4) were more severely and si gni f Tcantly
impacted than those in the shel terwood counterpart (treatment 1 ) . Among the treatments
where residues were left, populations in treatment 2 were significantly greater than
in either treatment 3 (also a shel terwood) or treatment 5 (clearcut).
In comparing staphylinid populations between the last pre-burn sample and the
two post-burn samples in 1975, there were no significant changes in any of the treat-
ments or in the undisturbed forest. In 1976, there a peared to be an effect of
harvesting, though not of residue treatment on sta hy inid populati~ns. Row beetles
were significantly more numerous in all of the she P terwood treatments, especiqlly
treatment 3, than in either of the two clearcut treatments. There was no significant
difference in populations between clearcut treatments 4 and 5.
From 1975 to 1976, populations increased significantly in a1 1 three shel terwood
treatments but not in clearcut treatments 4 and 5; in the undisturbed forest (treat-
ment 6) rove beetles increased by 50 percent. Because of the increase in the controls,
the implications of increases in the three shelterwood treated areas is uncertain.
Effects of harvesting on rove beetle populations appeared to continue in 1977 ;
populations in all three shelterwood treatments were significantly higher than the
two clearcut treatments. However, a residue treatment effect was not apparent.
There was neither a significant difference in rove beetle numbers among the three
shelterwood treatments nor between the two clearcut treatments. In 1977, beetle
populations were still significantly higher in the undisturbed forest (treatment 6)
than in any of the other five treatments.
Between 1976 and 1977, populatjons in both burned treatments (3 and 5) and in
the clearcut with mechanical residue removal (treatment 4) showed significant reduc-
tions. These population changes may have biological imp1 ications, since beetle
populations in the controls remained stable between the two years.
ARANE I DA
Spider populations were relatively stable in 1975 (figure 7, top), but there
were some treatment differences. Only two treatments (1 and 3) were significantly
lower than the controls. In the intense fiber utilization treatments, spiders were
significant1 more numerous in the clearcut (treatment 4) than in the shel terwood
(treatment 1 3 . Spider population changes following burning in 1975 were inconsistent
with respect to harvesting or residue treatments.
Population stabi 1 ity among the five treatments and the undisturbed forest con-
tinued in 1976, though there was an increase in numbers in all. six treatments over
1975. Significantly higher populations in 1976 in treatments 3 and 5 would seem to