Coarse woody debris (CWD) provides important ecological services and supports high levels of forest biodiversity. Some estimates suggest that 1/3 of all forest species reside in dead wood. However, forest management practices (particularly prescribed burns) and modified disturbance regimes have resulted in the loss, fragmentation, and degradation of CWD. Thus, we need to identify how attributes of CWD influence saproxylic community (those organisms associated with decaying wood) richness and species abundances, and develop strategies to incorporate important CWD attributes into forest management practices. Members of my lab and I have initiated a research project to explore how forest stand composition and fire history affect the distribution and abundance of CWD, and the composition and structure of the saproxylic arthropod (meta)community.

Dead wood with evidence of O. disjunctus galleries		Prescribed Burns Affect Dead Wood Distribution and Abundance

Concurrently, we are conducting experiments with Odontotaenius disjunctus (Coleoptera: Passalidae), a species potentially very sensitive to CWD modifications, and a possible indicator of forest health and saproxylic species diversity. As with many CWD inhabitants, O. disjunctus is primarily flightless, and therefore probably greatly affected by management practices, such as prescribed fires, that decrease the abundance and increase the spacing of CWD.

O. disjunctus Larvae		Adult O. disjunctus

O. disjunctus movement paths are relatively straight.  Each point represents the beetle’s location at 1-min intervals.

In one set of experiments, we are quantifying O. disjunctus dispersal behavior in forest stands with different compositions and fire history. These beetles are large (on the order of 4 cm) and easy to monitor their dispersal by simply following them in the forest and marking their positions at 1-minute intervals. We are also characterizing the spatial population-genetic structure of this beetle in order to elucidate the scale of gene flow within and among forest stands. With the assistance of Dr. Mohamed Noor, we have already begun developing microsatellites for this species.

DNA sequence from microsatellite enrichment of O. disjunctus.

One of our long-range goals is to use this research to help guide development of CWD management strategies, and set the stage for future studies that include experimental manipulations of CWD, large-scale evaluation of management practices on saproxylic communities and CWD, and mathematical models that simulate impacts of alternative CWD management practices.