Research Scientist Natural Resources Canada Edmonton, Alberta, Canada
The exploration for oil and gas in the Alberta oilsands involves the removal of forest cover along narrow corridors constructed to facilitate mapping underground bitumen deposits using seismic technology. Over 60 years of exploration have created a network of corridors (seismic lines) that extends over thousands of kilometers across the province. Peatlands are sensitive to this disturbance as many lines remain on a state of arrested succession, with little or no evidence of recovery several decades after construction. Much research has focused on vegetation or wildlife, but little is known about invertebrates, which are sensitive to forest disturbance and play important roles in the ecosystem. Here I present results from ongoing research that aims to document changes in spider composition and diversity in various fragmented peatlands across the province. Although similar patterns were observed between seismic lines and their adjacent peatlands, results suggest a large variability in response among locations. Species composition was consistently different in each habitat following a ground moisture gradient, with a tendency of higher species richness along the wetter seismic lines. Of the 232 species recorded, 18% were uniquely collected in the adjacent peatland, while 23% were uniquely collected in seismic lines. Species most abundant on seismic lines, known to be open habitat species, were among the most abundant in the adjacent peatland, suggesting an important influence of the disturbance on the overall spider community. Despite being narrow corridors, the wide-spread footprint implies an important top-bottom landscape level effect due to the predatory role of spiders.
