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
Tree of Life (craft) luxurious pieces began to be produced. This type of work is typified by the tree of life, especially those that are not religious in function. These non-religious trees have themes such as death or spring. The construction of clay tree sculptures with the Biblical theme of the Garden of Eden began in Izucar de Matamoros in Puebla State and spread to other areas, particularly to Metepec, Mexico State, which distinguished their trees by painting them in bright colors. The tree sculptures have become emblematic of this municipality, and are part of a clay sculpture tradition found only here. Other common