Evaluation of Plant Species and Grass Seed Mixes for Mined Land Revegetation Year 3 (1991) Results

Abstract

Careful selection of plant species in a seed mix is important for successful reclamation. The main purpose of grass seed mixes is to establish a living plant cover to stabilize soils at least in the short term. Grasses have a fibrous network of roots which is instrumental in stabilizing soils before outplanted woody species or local colonizers can establish additional roots. Sometimes the grass cover is the end product; other times grass cover is temporary until local species colonize and form a more diverse, natural community. Where moose browse is a desired goal, the grass cover should not compete with the woody plants. At other times, dense grass cover may be needed to suppress undesired native species, such as bluejoint (Calamagrostis canadensis). This same competitiveness may also suppress desired local species and reduce the diversity, thus being a negative factor. The grass species should be able to compete with each other to create a diverse mix. The pH and nutrient levels of soils may also limit the plant species that will grow well. Local species are plant species growing in the area, whether they are native or introduced (possibly by past disturbances in the area or the surrounding region). Native species are indigenous to Alaska but may not grow in the local area. The objectives of this study were to determine: 1. The grass cultivars that would grow on low pH soils (5.2) in the Wishbone Hill area. 2. A ratio of grass species within the seed mix that would improve the diversity of the resultant community. 3. A seeding rate that would allow establishment of local species and outplanted browse without jeopardizing the cover needed to stabilize the soils.