Reclamation with Native Grasses in Alberta: Field Trial Results

Resource Type
Authors
Russell Ecological Consultants
Resource Date:
1987
Page Length
57

Between 1978 and 1981 the Alberta Forest Service established 10 native grass field trials. The general objectives were: (1) to select the most promising native grass species for reclamation of high elevation disturbances in the Eastern Slopes; (2) to design and evaluate native grass seed mixtures; and (3) to develop recommendations for establishing and maintaining native grasses on high elevation disturbances. This report gives the first long-term results from these trials. Species performances were generally poor in the species adaptability trials at Cadomin. The wheatgrasses, especially Agropyron dasystachyum, A. trachycaulum and A. trachycaulum 'Revenue ' performed best overall. Phleum alpinum, Poa interior and Trisetum spicatum were considered failures. Contrastingly, most species performed reasonably well in the species adaptability trial at Mildred Lake. On both trial sites the cultivated species performed equally as well as their native counterparts. The performance of the native grass mixture was poor in the nurse crop x fertilizer rate x seeding rate trials at Cadomin. Fertilization produced a significant increase in plant cover. Neither the nurse crop nor the seeding rate treatments had any significant effect on the performance of the seed mixture. Seed mixtures containing wheatgrass species, especially dasystachyum, performed best in the four seed mixture trials. In contrast, the only seed mixture lacking a wheatgrass generally had the poorest results. The cultivated companion crops had little or no effect on the plant cover of the native grass mixtures. The best native grass mixtures performed equally as well as the best cultivated grass-legume mixtures. In the establishment methods trial at Cadomin the most successful treatments were those that covered and protected the seed. Drill seeding and broadcast seeding followed by application of a mulch produced the highest plant covers. The hydroseeding treatments, in which the seed and mulch were applied together, gave the lowest plant covers. The results from this trial suggested that native grasses, if established properly, can produce adequate cover for erosion control purposes. The revegetation treatments were generally more successful on the native mineral soil than the coarser textured overburden. Most species produced higher plant cover on the mineral soil. Furthermore, the mineral soil supported substantially higher species richness (number of species), indicating the plant communities were more diverse on mineral soil than overburden.