Impact of microsites on reclamation of Alberta native grasslands

Dr. M. Anne Naeth | Professor and Director, Land Reclamation International Graduate School
Department of Renewable Resources
Faculty of Agricultural, Life & Environmental Sciences
University of Alberta

This research investigates whether microsites enhance germination, emergence and establishment of seeded native forb and grass species. Dr. Naeth and co-investigator Dr. Anayansi Cohen Fernandez (Post Doctoral Fellow, Department of Renewable Resources) applied micro topographic treatments, including depressions (pits), mounds and flat land, to experimental plots at the Mattheis Research Ranch, at a reclaimed well site (Devonian Botanic Garden) and a landfill (Elk Island National Park) in the aspen parkland. The research team assessed effects of these microsites with and without five amendments (hay, straw, manure, hydrogel, erosion control blankets) to enhance soil properties, including soil water content and temperature. At the Mattheis Ranch, pits enhanced seedling emergence in the first but not the second year. Survival in pits was lower than in other microsites at all sites. Grass and forb species in flats at the Mattheis Ranch had the lowest cover, supporting the hypothesis that micro topography enhanced environmental heterogeneity and plant productivity. Addition of hydrogel to the soil resulted in greater plant cover at the Mattheis Ranch and therefore should be considered as a reclamation amendment in dry environments. Straw, hay and erosion control blankets enhanced grass and forb seedling emergence and establishment on flats or mounds on all of the sites. The exception was at Mattheis Ranch where higher application rates were not as favourable to grasses, specifically, blue grama. The researchers concluded that straw and hay are good amendments to enhance early native grass and forb establishment as long as the sources are weed free and application rates are not higher than 0.3 kg/m2; erosion control blankets improve revegetation success on flat or contoured topography; manure is not beneficial to native plant emergence or early establishment, however, if high plant cover is desired, its use with species tolerant of high nutrient loads would be appropriate; and a diversity of native grasses and forbs should be seeded on grassland reclamation sites regardless of microsites and/or amendments used as this helps buffer variability in revegetation success caused by variation in environmental