Soil fauna provides processes of crucial importance for ecosystem functions, but our ability to observe their actions often depend on destructive methods where the integrity of the studied environment (the soil) is compromised. In this study, I develop and test a new generation of environmental monitoring tools that utilize vibrations made by soil macrofauna to inform about their performance and health. Three hypotheses were tested on forest ants (Formica sp.): (i) vibrations on a naturally occurring substrate can be used to measure the activity of ants, (ii) the vibrational signature of ants can inform us about the ants’ health, and (iii) behavior (locomotory activity, foraging etc.) of ants is correlated to specific vibrational signal characteristics. Vibrational signals from ant sub-populations (5 individuals/sample) were recorded on natural substrates (leaves) before and after exposure to sub-lethal levels of a contaminant with known negative effects on ants (imidacloprid). Activity was successfully detected from the inferred vibration oscillograms. However, neither the number of vibrational signals captured, or the signal characteristics changed after imidacloprid exposure, indicating that either the exposure was too low to generate a change in behavior or that the technique was unable to detect subtle changes in behavior. Signals of short duration and amplitude were generated by locomotory activity, but their intensity was dependent on the distance to the vibrometers laser focus point. Longer signal segments were either continuous, random, or rhythmic in their distribution. I suggest that these signals are a result of methodological artifacts, movement of multiple ants, and stridulation/drumming on the substrate, respectively. My findings suggest that this advanced monitoring tool is sensitive enough to capture activity from only a few ants, but the characteristics and number of captured signals are strongly affected by the measured substrate

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<p dir="ltr">To examine how forest management affects terrestrial salamanders, this dissertation: (1) examines the effects of timber harvesting strategies on salamanders; (2) examines the effects of prescribed fire for oak regeneration on salamander populations; and (3) explores the influence of artificial cover object (ACO) wood type, size and shape, and placement on salamander monitoring results. These projects were conducted at the Hardwood Ecosystem Experiment (HEE) and Martell Experimental Forest in Indiana. Long-term salamander monitoring data from the HEE were used to examine the effects of clearcuts, shelterwoods, and patch cuts on salamander captures collected up to eleven years post-harvest and were analyzed with a before-after-control-impact (BACI) design. Clearcuts and patch cuts had negative effects on salamanders 4-6 years post-harvest, which coincided with a drought; however, preparatory and establishment shelterwood harvests showed no effects on salamander captures, suggesting that retaining canopy cover may protect salamanders from compound disturbances such as drought. Also at the HEE, capture-recapture techniques were used to examine salamander population estimates before and after fire. Only two of three fires affected salamander populations. In the short term, prescribed fire effects on salamanders may be weak and intermittent and microclimate may have a greater effect on populations, although the longer-term effects of fire remain unknown. At Martell Experimental Forest, salamander numbers were compared beneath ACOs of different wood types, sizes and shapes, and grid arrays of different spacings. Pine ACOs were preferred over ash, while several small ACOs yielded equal salamander numbers to one large ACO of equal total area. High ACO density may increase capture probability but reduce the area sampled by each ACO, while lower density ACO grids may cover a larger area with the same sampling effort and produce more comparable results, but with less precision; choice of ACO experimental design will therefore require careful consideration of management goals. This dissertation also suggests strategies to support salamander populations as guidelines for managers to consider in management planning.</p>