Stander Symposium abstract book - University of Dayton

9:00 AM to 5:00 PM
Forensically Important Insect and Metabolic Community Differentials via Vertebrate
Scavenging
Presenter(s): James M Alfieri
Advisor(s): Mark E Benbow
Biology
3:20 PM-3:40 PM
Independent Research Kennedy Union - 211
Blow fly (Calliphoridae) species identification is crucial to estimating a post-mortem interval (PMI) and is important for understanding the ecology
of carrion decomposition. However, persisting low temperatures will greatly reduce blow fly activity, and thus affect PMI estimates during colder
seasons. This leaves the process of decomposition to microorganisms that can survive low temperatures, and vertebrate scavengers. The effect of
these vertebrate scavengers on blow fly colonization and succession has not been thoroughly described or quantified. In this winter field experiment,
six Sus scrofa carcasses were randomly placed along a field edge in Farmersville, Ohio. Three of the carcasses were placed in exclusion cages
to prevent vertebrate scavenging and thus acted as a control. The remaining three were left accessible to scavengers. Stealth game cameras were
set to record any motion around the carcasses, and thus any scavenging events. Initial and periodic microbial swabs were taken when scavenging
occurred on a carcass to provide a metabolic profile of the microbial communities of the carcass. Data suggest that there is a linear relationship
between scavenging incidents and temperature. Also, carcasses that were scavenged have decomposed at an exponentially higher rate than those
not scavenged. There was also a difference in microbial community metabolic profiles among the scavenged carcasses compared to the control
carcasses.
Beta diversity dynamics across topographic gradients in the herbaceous layer of an
old-growth deciduous forest
Presenter(s): Julia I Chapman
Advisor(s): Ryan W McEwan
Biology
3:40 PM-4:00 PM
Graduate Research Kennedy Union - 211
Herbaceous species composition and productivity are known to vary with topography (i.e. slope, aspect, elevation), but how this spatial variation
is linked to temporal dynamics is not well studied. We investigated the influence of topography on seasonal species turnover (beta diversity
between time points) and vegetative cover over a growing season. We hypothesized that (H1) the magnitude of herbaceous layer species turnover
would vary with aspect, elevation, and slope (in order of decreasing importance), (H2) herbaceous cover would vary significantly with topography,
and (H3) the strength of these relationships between species turnover/cover and topography would change through the growing season. The herbaceous
layer was sampled in April, June, and August of 2011 within 320 1m2 plots stratified throughout an old-growth central Appalachian forest.
Percent cover was estimated for each species, and species turnover was calculated as Bray-Curtis dissimilarity.Mean seasonal species turnover
was significantly greater (P < 0.001) between April and June (0.56 ± 0.02 SE) than between June and August (0.27 ± 0.02). Seasonal species
turnover was generally not statistically related to topography; however, a weak linear relationship was found between aspect and turnover across
the entire growing season (April to August; r2 = 0.05, P < 0.05), suggesting greater species turnover occurred on north-facing slopes. Herbaceous
cover varied with elevation, and this significant quadratic relationship (P < 0.01) was consistent over time. The linear relationship between cover
and aspect was stronger in April (r2 = 0.08, P = 0.01) than June (r2 = 0.05, P = 0.05), but did not exist in August. Slope was not a significant
predictor of cover. Overall, local topographic variation related more strongly to herbaceous cover than species turnover, but these relationships
were weak. Further work is needed to understand drivers of herbaceous layer dynamics and their interactions in eastern deciduous forests.
108