Research Interests

I am generally interested in the effects of human activities on biodiversity, particularly those involving linear ingressions into intact habitat and the effect of human-introduced exotic species.  Under this very broad subject I have several ongoing research projects. These projects have grown out of my interest and long-term studies of rove beetles and their kin (Series Staphyliniformia). In particular, the taxa that have served as the model organisms for most of these conservation biology studies have been beetles in the staphylinid Subfamily Aleocharinae and the Family Silphidae.

Current Projects

• Road Intensity and Necrophage Biodiversity at the Black Rock Forest

Roads form a serious threat to animal life across biomes for a diversity of reasons.  Roadside mortality from collisions, increased aridity, brightness, exposure to the elements, and a host of other edge effects all have a significant negative and direct impact on overall biodiversity.  Additionally, many animals can sense when a road is nearby merely when they are near the edge and choose to avoid it.  These indirect impacts of roads serve to greatly widen the area of impact of roads and are the focus of this aspect of my lab's work at the BRF.  We are investigating the impact of many road types, from heavily traveled four lane divided highway to low-use single lane dirt roads, on the biodiversity of necrophage beetles.
 
• Corridor Efficacy in the Moist Atlantic Forest, Sao Paulo, Brazil in collaboration with the Instituto de Pesquisas Ecologicas

In order to effectively manage biodiversity within fragments we need to develop a holistic method of analyzing the impact of fragmentation on all organisms in the ecosystem. To date, nearly all of the fragmentation studies in the tropics have involved vertebrates and have not taken advantage of the tremendous diversity and informative power of insects. Knowing how fragmentation and corridors affect or benefit all of the organisms is essential to being able to manage the forest fragments so as to maximize diversity.
The studies we are conducting using butterflies and necrophage beetles will help to develop more effective strategies for minimizing the impact of fragmentation events, which will become even more common with increasing world population. The results we are obtaining as a consequence of this work will provide essential information for a planned conservation restoration project in the Mata Atlântica that could involve a community-based floristic enrichment of local home gardens in order to promote the connection of isolated forest fragments and maintain the maximal possible diversity. We hope that these data will help to clarify the utility and desirability of corridors.
 
• Introduced Hemlock Woolly Adelgid Impact on Eastern Ecosystems at Black Rock Forest

Imported from Japan to the northwestern US from Japan in the late 1940s, the HWA quickly spread to the East coast and began to increase in population size.  Only in the last ten years or so has it started to exert a toll on the Eastern Hemlock, Tsuga canadensis. We are determining the direct and indirect effects of the introduced herbivorous Hemlock Woolly Adelgid (Adelges pseudotsuga) insect on the Eastern Hemlock, a local key species in upstate New York, and many of the animal species associated with the Hemlock. This work includes scientists from the Black Rock Forest (Aaron Kimple - a Forest Ecophysiologist), American Museum of Natural History (Vladimir Ovtsharenko - a Spider Systematist), and myself.
My part of the collaboration is attempting to answer two questions. First, is the Hemlock Woolly Adelgid (HWA) the main insect affecting tree health in this area or is the Elongate Hemlock Scale (another introduced plant feeder) the chief culprit of hemlock death? Second, has the HWA explosion also had indirect third and fourth order affects on overall arthropod community diversity and some of their associated ecosystem functions?
 
• Crazy Ants as a Model Exotic Species at Biosphere 2 and Hawaii

When exotic species are introduced into novel habitats they frequently become superabundant. This rapid increase is usually because of the absence of predators, competitors, or parasites that would otherwise keep their population sizes in check.  When this occurs, invasive species can extirpate huge numbers of species, often ramifying throughout the rest of the ecosystem, potentially significantly altering normal ecological processes and restructuring entire ecosystems. This phenomenon has happened within the artificially constructed habitats in the domes of the Biosphere 2 center (B2C) due to the accidental introduction of the crazy ant (Paratrechina longicornis). The 11 ant species that were originally intentionally introduced into B2C have nearly all become extinct within the domes, and by far the ecologically dominant ant and potentially the most dominant animal within the B2C terrestrial ecosystems is P. longicornis. Some have suggested that is it because of the ant that the leaf decomposer community has been so greatly reduced in the tropical biome.  As a consequence, this biome is experiencing a large build-up of undecomposed organic matter.
Although P. longicornis is thought to have been native to either India or tropical Africa, it has been introduced around the world and is now most commonly encountered in and around human habitations.  It is frequently the most common ant species present in these artificial habitats. Therefore, despite the fact that the B2C is a human construct, it is a perfect field site to study this ecologically important ant species. Notwithstanding the ecological dominance in disturbed habitats around the world and within this important research and educational facility, very little is known about the basic biology of P. longicornis.
My research at the B2C involves determining the impact of this exotic species on the domes and on the surrounding desert, as well as the degree of biomass flux that occurs between the two environments as a consequence of the crazies. The work in Hawaii will involve the impact of the ant on intact habitats, as no ant species is indigenous to Hawaii.  The impact of P. longicornis on B2C and Hawaii are thus excellent analogues of islands for invasion biology.
 
• Impacts of Fragmentation on the Albany Pine Bush

The Albany Pine Bush, a globally rare and critically endangered ecosystem, is the largest remaining inland pine-oak barrens habitat in the world. There are 19 species found there that are on the endangered or threatened species listings, although none of them is found only there. Currently, the most significant threat to the Pine Bush is the pressures placed upon it by habitat fragmentation and suburban development. The entirety of the remaining Pine Bush habitat is within the city limits of Albany, Schenectady, Guilderland, and Colonie.
We are interested in how fragmentation and road use will impact upon the remaining communities, particularly in how several Lepidoptera species are impacted by these intrusions.
I have also testified at City Council when some ill-advised developments have been proposed in the remaining habitats. A slide show discussing the impacts is available here.
 
• Pest and Parasitoid Diversity in New York City Community Gardens

Several hypotheses have been advanced that collectively advocate for the control of crop pests by naturally occurring predators and parasites. Much of this work has occurred in rural settings, with very little examining whether these patterns hold true in an urban environment. There are over 650 gardens in the metropolitan NYC area with most located in diverse, lower-income communities and which serve as important resources for community members. We tested the corollary trophic interactions model that an increase in plant, pest, and parasitoid insect diversity would all be positively correlated in these gardens. This model and a postulated negative relationship between pest and parasitoid richness were not supported by our data. Garden size was the principal determinant of all three diversities. It seems that in these urban environments, the fragmentation and isolation may restrict the applicability of models that hold true in more natural environments.
This work is still preliminary and will be expanded on in future years.