Date of this Version
In 1976, we began a comprehensive evaluation of "Vexar" seedling protectors as a means of reducing damage to conifer seedlings by pocket gophers (Thomomys spp.). The protectors are cylinders of plastic netting that gradually decompose in sunlight. The evaluation is being conducted on four national forests in three western states. Three conifer species, lodgepole pine (Pinus contorta), ponderosa pine (P. ponderosa), and Shasta red fir (Abies magnifica var. shastensis), are under study. After two growing seasons, gophers have caused only 5 percent mortality among "Vexar"-enclosed seedlings compared to 20 percent mortality among unprotected seedlings. In addition, stocking and heights of protected seedlings are better than those of unprotected seedlings. Problems associated with the use of "Vexar" included compression of the protectors by snow, breakage of the plastic during subfreezing temperatures, and protrusion of seedling terminals through mesh openings; however, these problems have been minor thus far. Information on long-term effectiveness and cost efficiency is still needed before we can recommend operational use of "Vexar" protectors for pocket gopher damage control.