Modeling lodgepole pine silvopastures in south central British Columbia

Silvopasture systems within lodgepole pine stands in British Columbia are not widely implemented because knowledge is lacking on profitability, appropriate tree and cattle stocking standards, and the suitability and potential of understory forage species in silvopasture systems. In order to compare total timber and forage production values of single-crop tree plantations with those of silvopasture systems, this study consists of: 1) a theoretical economic model (the Lodgepole pine Silvopasture Economic Model) that predicts revenues expected for tree-only, pasture-only, and both uniform- and clumped-tree distribution silvopasture systems, and 2) a screening of native and agronomic forage species under simulated shade conditions to compare forage quantity and quality for grazing beef cattle. The Lodgepole pine Silvopasture Economic Model relies on a constant supply of mean production values projected into the future to estimate and compare the yield and value of resource commodities. The objectives of the forage screening component were to compare agronomic and native grass biomass production and forage quality, and study the effects of shading, clipping, and their interaction, on pinegrass and rough fescue, two species native to British Columbia, and the agronomic forages orchardgrass and perennial ryegrass. Some morphological changes under shade were noticed in this study, but the effects were minimal in comparison to differences in biomass production between species. The study clearly demonstrated the high productivity of orchardgrass compared to pinegrass and rough fescue as orchardgrass plants produced a total of 11 and 9 times more total biomass than pinegrass and rough fescue under ambient sunlight, but the differences between species factors tended to decrease with increasing shade. The benefit of improved forage production using agronomic species in clumped distribution lodgepole pine silvopasture systems has the potential to provide sizeable benefits to the ranching industry while diversifying resource commodities in lodgepole pine stands.