Proceedings of the Vertebrate Pest Conference

A combination of factors are responsible for mortality in conifer plantations. Ponderosa pine (Pinus ponderosa) were planted on 3 transitory ranges in northern and central Idaho. These plantations were followed closely (sampling up to 7 times per year) for 6 years recording the causes of mortality and damage to the tree seedlings. Pocket gophers (Thomomys spp.) killed the most trees (71%) while nonanimal causes killed 21%. Elk (Cervus elaphus) and deer (Odocoileus spp.) killed a maximum of 9%, and cattle (Bovine spp.) killed a maximum of 4%. Pocket gophers caused the most reduction in height growth. The combination of factors caused excessive damage and mortality at all study locations, completely destroying one plantation.