Investigating the Temporal and Spatial Distribution of Phragmites in River Canard using Remotely Sensed Imagery
Abstract
Phragmites australis is a common reed that invades wetlands and marshes in North America. Recent expansion of this invasive species into the Great Lakes wetlands has caused concern amongst scientists, as the invasion of this species has been shown to have detrimental consequences within ecosystems, reducing species diversity, changing the structure and function of wetlands, and threatening important food sources and habitat for wildlife (Meyerson et al., 2000). Remote sensing technology has allowed resource managers and scientists to analyse wetland change or monitor vegetation within wetlands seasonally or yearly due to the repeated coverage. The Essex Region Conservation Authority reported that Phragmites expansion has greatly increased since the mid 1990s, replacing cattail and purple loosestrife which have been dominant in Essex County. Due to the limited study conducted on Phragmites expansion within River Canard, located in Amherstburg, Ontario, this study examined the temporal and spatial extent of Phragmites from 1989 to 2009. Remote sensing imagery and aerial photographs were used to delineate and map Phragmites expansion, and provide effective maps showing the gradual increase and in-land spread of Phragmites within the study years. While only a portion of the River Canard which drains into the Detroit River was studied, this research helps to provide a starting point and guide for future Phragmites modelling within Essex County using aerial photographs and remote sensing images.