Much of my research at revolves around these questions. Although my taxonomic expertise is for spiders, I use macro-arthropod (spiders, ants, and beetles) communities when studying how organisms respond to their environment and to each other. Many arthropod communities are closely linked to ecosystem processes: I am studying how arthropod communities on the forest floor are linked to ecosystem processes such as nutrient cycling.

Current projects:

Project under development!
This project will provide an assessment of the presence, distribution patterns, and ecosystem effects of earthworms in southern Ontario forests (Great Lakes/St. Lawrence region). More specifically, we will determine how earthworm distribution and spread is associated with human land use, and how, across geographical gradients, earthworms alter forest nutrient cycling, soil structure, and biotic communities, including the potential facilitation of plant invasions.

Collaborators: Nathan Basiliko, Department of Geography, University of Toronto, and Sandy Smith, Faculty of Forestry, University of Toronto.

We can use altitudinal gradients to understand how community structure and interactions vary along a temperature gradient. For example, how does the influence of ants, which are dominant species in forest floor ecosystems, change with temperature? Interactions among species are also affected by habitat complexity, which in forest floor environments is correlated with litter depth.

In collaboration with Nate Sanders and J.P. Lessard (University of Tennessee) I am studying how how arthropod communities (spiders, ants, beetles, centipedes, and microarthropods) are structured by the presence of a dominant ant species (Formica fusca var. subsericea Say), and how these effects are modulated by litter depth and altitude. This research is being done at the Coweeta LTER site in North Carolina.

Invasive species displace or extirpate native species and change the structure and functioning of communities and ecosystems. The invasive Hemlock Woolly Adelgid (HWA) is killing hemlocks (Tsuga canadensis and T. caroliniana) in eastern North America. Hemlock is a foundational tree species, meaning that the characteristics of this species define community structure and ecosystem processes. Because of this, the destruction of hemlock by the woolly adelgid will affect many associated species and ecosystem processes.

In collaboration with Nate Sanders, Aimee Classen (University of Tennessee) and Aaron Ellison (Harvard Forest) I am studying how ground dwelling arthropod communities and nutrient flow are affected by changes in forest type and litter fall from the loss of hemlock due to infestation by the HWA. This research is being done at Harvard forest in Massachusetts.

The interdependence of aboveground and belowground food webs is an important link within ecosystems, with aboveground producers providing carbon to the soil and litter community, and the decomposer community breaking down organic matter and releasing nutrients into mineralized forms that are then available for plant absorption.

In an armchair ecology study, I am synthesizing data from published studies via meta-analysis to understand how the structure of faunal communities in soils is linked to aboveground productivity.