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Resource pulses can have both direct bottom-up and indirect top-down effects on their consumers, but comparatively few studies have investigated the top-down effects of naturally occurring resource pulses on plants. This study describes two years of field experiments conducted to determine the indirect effects of 17-year periodical cicadas (Magicicada spp.) on herbivory in American bellflowers (Campanulastrum americanum). In 2004, the area of damaged leaves on cicada-supplemented plants was 78% greater than the area of damaged leaves on control plants. In 2005, cicada-supplemented plants were more likely to experience herbivory by mammalian herbivores than control plants. When large herbivores were excluded, similar patterns of leaf herbivory were observed, but these differences were not statistically significant. These results suggest that the pulsed input of dead periodical cicada bodies increased rates of herbivory on bellflowers, and that this effect was largely mediated by the selective foraging of large mammalian herbivores. More broadly, this study suggests that pulses of limiting resources can have both positive direct effects on plants and negative indirect effects due to selective herbivory, and that the net effects of pulsed resources on plants may depend on the composition and behavior of the surrounding herbivore community. Key words: bottom-up effects; Campanulastrum americanum; fertilization; foliar nitrogen; Magicicada spp.; periodic cicada; pulsed resources; resource pulses; satiation; selective herbivory; top-down effects; white-tailed deer.

To assess the effects of deer browsing on understory composition, we examined hardwood forests with documented differences in browse intensity within two regions of the Hiawatha National Forest in Michigan's Upper Peninsula. A deciduous twig damage assessment confirmed that two sites within the southern region experienced high white-tailed deer (Odocoileus virginianus) browse intensity (44-49% of twigs browsed) and two sites within the northern region incurred low browse intensity (0.5% and 0.6% of twigs browsed). We used within-site sample means and site-level rarefaction curves to compare understory species richness in these two forests. The forest experiencing low browse intensity had higher woody species richness on a per plot basis than the heavily browsed forest, but the converse was observed for herbaceous species richness. Site-level evaluation with rarefaction curves confirmed the plot-scale results for herbaceous species, but different patterns in woody species richness emerged due to differences in the distributions of species across the four sites. When graphed as a function of cumulative number of plots, we again found that a low browse site had the highest woody plant species richness, but a high browse site had the highest richness values when richness was graphed as a function of cumulative number of stems sampled. This study demonstrates that although species richness is a useful tool for describing ecosystems, results for the same sites can differ based on how species are grouped and on the scale of analysis.

We compared the germination rates of running buffalo clover (Trifolium stoloniferum) seeds that had been passed through the digestive tract of a captive white-tailed deer (Odocoileus virginianus) with those that had not. We found no significant difference among germination rates of seeds passed through deer and those not, nor with seeds that were cold-stratified prior to planting and those that were not. Although white-tailed deer are viable vectors for running buffalo clover seed, our data suggest that the rates of ingested seed germination and survival are low. Dispersal and establishment of new populations by white-tailed deer herbivory may not contribute quickly or significantly to the recovery of running buffalo clover at present.

An eight-year selection process is applied in an attempt to determine if yearling antler in subsequent cohorts could be improved by selecting for yearling male white-tailed deer exhibiting superior antler potential under suboptimal nutritional conditions. Result provides an insight to the effectiveness of a selection process in an overall deer management program.

The winter forage selection in white-tailed deer at high density shows a preference for balsam fir mainly due to its low content of tannins and fibers.

The impact of Key deer herbivory on natural vegetation near urban areas was studied by comparing plant densities and diversity in hardwood hammocks adjacent to urban and distant from exurban developed areas. No differences in total plant species or diversity on islands with high densities of deer were detected and testing of deer browsing intensity on islands of high deer density showed browsing pressures to be higher on preferred plant species in hammocks near urban areas than exurban areas.

Arboreal lichen production and availability for Rock Mountain elk, white-tailed deer and mule deer during winter in Western Montana was studied. A strong linear relationship between lichen availability and lichens consumed showed that lichen use was driven by availability rather than by opportunistic foraging, and that ungulates might have selected habitat due to lichen availability.