From Reclamation to Restoration: Native Grass Species for Revegetation in Northeast British Columbia
Grasses are widely used in revegetation to control erosion, build soil and maintain habitat. In northeast British Columbia, non-native grass species are commonly seeded to reclaim industrially disturbed sites. Widespread concern about degradation of biodiversity and key ecological processes has led to increasing value placed on native species and management practices leading to a more resilient landscape. I undertook this study to fill the restoration knowledge gap relating to native grasses in northeast BC. I did an extensive inventory of grasses on 217 sites in 2007, 2008 and 2009. Functional traits were measured in the field and in a greenhouse growth experiment. I found ninety-nine grass species occuring in the region, 70% of which are native. The number, proportion and extent of non-native grasses are increasing and four of these Poa pratensis, Festuca rubra, Bromus inermis, and Phleum pratense represented almost a quarter of all occurrences. Several native species were common throughout the region: Calamagrostis canadensis, Leymus innovatus, Elymus trachycaulus, Poa palustris and Agrostis scabra. Other native species, including Festuca altaica, Koeleria macrantha, Pascopyrum smithii, and Schizachne purpurascens, strongly favoured intact habitats. Elevation, soil moisture regime, proportion of bare ground, and land use were significant factors related to local grass species composition and abundance. Agrostis scabra, Alopecurus aequalis, Beckmannia syzigachne, Bromus ciliatus, Cinna latifolia, Deschampsia cespitosa, Elymus alaskanus, Elymus trachycaulus, Festuca saximontana and Hordeum jubatum grew commonly on severely damaged well sites. Field measurements for Specific Leaf Area (SLA) and Leaf Dry Matter Content (LDMC) of 11 species showed an inverse correlation. Bromus ciliatus, Bromus pumpellianus, and Elymus trachycaulus had high SLA/low LDMC linked to rapid growth, whereas Festuca altaica, Deschampsia cespitosa, and Calamagrostis stricta had low SLA/high L.