Long-term agronomic and environmental impact of aspen control strategies in the Aspen Parkland

Abstract

Since European settlement the Aspen Parkland has been subject to agricultural intensification. This research assessed the agronomic, ecologic and economic impact of native Parkland conversion into tame pasture, by building on a study initiated in 1980 investigating the short-term agronomic responses within three landscape-level treatments: an intensive Clear & Break (C&B), a Spray & Burn (S&B) and a burnt Native Check (NC). Historical information was supplemented with recently collected data (2005-2006). Production remained high within the NC relative to the others after 25 years, in part due to contributions from browse in areas with increasing woody species. Plant species composition also demonstrated considerable convergence (i.e. overlap) between native and tame grasslands, and although not different in soil organic matter, microfaunal activity differed marginally. Net present value (NPV) economic analysis indicated the NC and S&B provided greater aggregate returns over the study period, and has implications for aspen management in the future.