Landsat-based monitoring of landscape dynamics at Grand Portage National Monument: 1995–2018

Kirschbaum, Alan

doi:10.36967/nrds-2293284

Landscape disturbances such as forest harvest, blowdowns, fire, and development activities create patches on the landscape that modify the structure and function of ecosystems and watersheds. Understanding the timing, location, size, and intensity of these disturbances can assist resource managers when making decisions regarding management options. In an effort to provide information regarding these metrics, the Great Lakes Inventory and Monitoring Network implemented a long-term monitoring project to quantify landscape dynamics inside and surrounding Grand Portage National Monument using an automated satellite-based change detection program called LandTrendr (Landsat-based detection of trends in disturbance and recovery). The analysis area encompassed three watersheds totaling over 83,000 hectares and spanned the years 1995–2018. Inside the park, the only disturbance detected was due to a defoliation event that totaled 60 ha. Lands adjacent the park experienced far greater levels of disturbance, with forest pathogen (defoliation) affecting 7.6% of the land, followed closely by forest harvest and blowdown at 7.4% and 6.3%, respectively. The blowdown occurred in the summer of 1999, the defoliation event occurred the following year (2000), and the forest harvest disturbances were relatively stable throughout the analysis period. Lastly, disturbances by beaver were observed across the analysis area and analysis time period, indicating their prevalence across time and space. Long-term monitoring of this analysis area will contribute to our understanding of how these disturbances may affect ecological processes inside the park.

Landsat-based monitoring of landscape dynamics at Grand Portage National Monument: 1995–2018

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