Land use and conservation values of farmland forests : outcomes of livestock grazing on the aspen forest understorey in the greater Riding Mountain region, Manitoba
Newman, Karin E.
The past 125 years of agricultural settlement in North America has resulted in extremely fragmented habitats. In farming landscapes, small patches of remaining native vegetation on private land are generally intermixed with agriculture or are actively grazed by livestock. This study takes place in the primarily agricultural rural municipalities surrounding Riding Mountain National Park (RMNP), Manitoba, Canada. Even as the critical necessity to engage in conservation beyond borders is recognized, the importance of native vegetation habitats on private land, including forest, is too often overlooked. Although livestock are widely perceived as adversely affecting natural habitat, relatively little is known about the impacts of livestock grazing on these remnant forest habitats. To examine the effects of cattle grazing on forests, the understorey diversity was compared across sites with different livestock grazing histories and intensities. Patch- and landscape-level environmental factors were measured at sites both in and around RMNP. The diversity of the matrix (non-forest) habitat of privately owned sites was invariably adversely affected by the intensity of agricultural land use, while forests showed more resilience. In forests, grazing intensity played a strong role in determining understorey composition. While livestock grazing tended to be associated with exotic species, only heavy grazing was significantly associated with increased cover of certain grazing tolerant exotic species. Other native perennials were associated with non- grazed or moderately grazed sites. Furthermore, moderate grazing had no effect on the native understorey diversity, as compared to non-grazed and past grazed landscapes. These results suggest that both protected forests and moderately grazed forests act as important refuges for native species in agricultural landscapes. A diversity of land uses, including moderate forest grazing, can be compatible with the protection of regional forests. Although National Parks are increasingly surrounded by intense human land uses, often very little is known about the conservation goals of neighbouring local communities. Management ideals, attitudes and values that local landowners held about privately owned forests were collected through a series of structured interviews and a mail-out questionnaire in communities within the Riding Mountain Biosphere Reserve, surrounding RMNP. Because knowledge in the farming culture is often passed down from previous generations, each individual farmer holds decades of personal observations about this environment. Thus, survey participants were an important source of local knowledge and observations on the conservation and use of native vegetation in their environment. Landowners in the study area are managers of a substantial amount of native vegetation, much of which was used for cattle production. Conservation motivations for maintaining relatively undisturbed land were often associated with function and environmental services, including erosion, water retention and habitat protection. Forest cover also represented a significant proportion of native vegetation on private land. Participating landowners voiced the importance of maintaining non-production land on their farms. Despite financial reliance on the land base, stewardship and conservation reasons were the main motivation plans to revitalise and preserve forested fragments in the greater Riding Mountain region will necessarily rely heavily on the knowledge experience and resources of local landowners.