Christmas tree pests and weeds required restrictions and requirements to be placed upon Christmas tree growers with plantations in "gypsy moth regulated areas". The restrictions and requirements included ongoing site monitoring, active moth eradication by the grower, accurate record keeping, and government directed moth eradication programs. Failure to abide by the rules could result in revocation of the "approved grower" status from the Canadian Food Inspection Agency. The major types of conifers cultivated, pines, Douglas-firs, true firs, and spruce trees, are all affected by some types of insect pests. Douglas-firs are most vulnerable to the Cooley spruce gall adelgid. The true firs are most susceptible
Douglas Ranges flows along the southeast flank of the range. East of the Douglas Ranges, across Harrison Lake, are the Lillooet Ranges, while to the west and northwest are the Garibaldi Ranges. Southeast across the Fraser River is the Canadian portion of the Cascade Range. Because of the warmer climate (relative to the rest, even, of the British Columbia coastal lowlands), there were forests of immense trees throughout the Douglas Ranges, which were logged relatively early on in British Columbia's history. A network of logging railroads ran throughout the basin of the Chehalis River, which drains the core of the ranges to