Sheep Grazing Guidelines for Managing Vegetation in Forest Plantations in British Columbia.
Sheep grazing has recently been introduced to British Columbia as a vegetation management option. In 1984, sheep producers requested grazing permits from the British Columbia Ministry of Forests in 100 Mile House to graze clearcuts with high fireweed cover. The possibility of using sheep to reduce vegetation competition in conifer plantations became apparent and the first sheep grazing trial was initiated in 1985. The Clearwater Forest District also started a trial in that year. Both projects showed that sheep grazing could become an effective method of brushing plantations. By 1986, enough interest had been generated to establish a formal trial at Doreen Creek in the Horsefly Forest District. These three projects, which used approximately 4000 sheep to graze just under 1000 ha, continued in 1987 and 1988. In 1989, sheep grazing was accepted as an operational tool by the British Columbia Ministry of Forests. By 1992, approximately 26 700 sheep were grazing over a wide range of environmental conditions on 6000 ha throughout the province. Project monitoring has shown that sheep can effectively control some species of vegetation that compete with conifer seedlings (Ellen 1988; Lousier 1990; Bancroft 1gg2a, 1gg2b; Erickson 1992; Sutherland et al. 1992). The purpose of most grazing projects has been to brush established plantations, but grazing was also used as a site preparation tool.
Since sheep grazing is a relatively new management option in British Columbia, there are no data available yet that can demonstrate statistically significant increases in seedling growth response. In the United States, however, increases in seedling growth rates have been observed on plantations where sheep grazed competing vegetation for a number of years. Sharrow et al. (1989) found a 796 increase in Douglas-fir seedling height and a 5% increase in seedling diameter three years after grazing. Jaindl and Sharrow (198~) found that Douglasfir seedling growth increases were still apparent 20 years after grazing was completed.
All sheep grazing projects should consist of three components: planning, implementation, and evaluation. Adequate planning of a sheep grazing project is essential to ensure that grazing treatments are properly applied and that silvicultural objectives are accomplished. Prepare a flexible written plan several months before the projects will begin. Try to anticipate problems and develop contingency actions to address them. Ensure that the plan follows the British Columbia Ministry of Forests protocols for Pre-Harvest Silvicultural Prescriptions. Also make sure that the plan is referred to all appropriate agencies and interest groups. They should either be involved in the planning process or have an opportunity to review the plan. The British Columbia Mini stry of Environment, Lands and Parks must have an opportunity to view the site at least 1 year before the project begins. See Section 11 for a detailed summary of scheduling activities.
This handbook will assist forest managers to evaluate sheep grazing as a vegetation management option and to implement sheep grazing projects. Information was obtained by reviewing scientific literature and internal reports. Two questionnaires were also developed to collect information from government and industry personnel, sheep grazing contractors, and sheep producers. The first focused on the effects of sheep grazing on target vegetation, and crop tree response. The second questionnaire was directed toward sheep producers and dealt primarily with sheep management. Appendix 2 lists the individuals surveyed and interviewed. Survey information, literature, and the interviews were evaluated to develop a consensus on managing sheep to successfully achieve vegetation management goals. Also, the"Interim Guidelines for the Use of Domestic Sheep for Vegetation Management in British Columbia" (Schwantje 1992) iS frequently referenced in this handbook. A final version of this document should be available in 1995.
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