A Synthesis of the 2001-2004 Peace Native Grasslands Program
This report summarizes activities performed as part of the Peace Native Grasslands Program between 2001 and 2004. Until this study was undertaken, very little was known about the current location, size, or condition of upland native grasslands in the Peace region. Historically, native grasslands were extensive and contiguous throughout the Peace region of northwest Alberta. Land development has heavily affected the landscape since the 1900s and the present study has shown that only 746 ha of upland native grassland remains; representing less than 0.5% of the original area. An additional 1,210 ha is yet to be fully evaluated. Current remnants of native prairie are distributed nearly equally between private and Crown ownership.
Interpretation of aerial photography identified 952 upland native grassland sites in the Peace region. Using field assessments, 395 of these sites were verified as being native grassland remnants and were subsequently described in terms of their plant communities. In addition, vegetation communities in valley native grasslands, moist native meadows and sphagnum peatlands were verified using aerial photographs. Based on field assessments, parcels of remnant upland native grasslands were very small in size with the vast majority (i.e., 97% of all sites assessed) sites being < 16.2 ha (i.e., 40 acres) and with 39% of all remnants being one hectare or less. The small size of remnant grasslands will affect the selection and application of potential management and conservation tools that can be used effectively and economically to conserve native grasslands.
Native upland grasslands are biologically diverse both within and among remnants and support both rare plant species and communities. Native grasslands in the Peace region also provide habitat for many animal species including several butterfly species that are dependent on specific grassland host plants. In fact, my data suggests that eight disjunct grassland dependent butterflies appear to have a strong affinity for native habitats. During this study, the known ranges for a number of plant, butterfly, and moth species were extended. Continued habitat disturbance and fragmentation represents an ongoing threat to the persistence of these and other species.
During the study period, baseline information was collected on upland native grasslands, and related data used by other agencies to support conservation of native prairie habitat. The availability of these baseline data means that more projects can, and are, being developed to address specific questions related to native grasslands, their management and their conservation.