Realized genetic gain trials
Progeny tests are conducted on tree breeds in British Columbia by measuring the quality of a tree’s offspring.
One significant problem with progeny testing is that as the test matures, trees suffer from competitive effects. This makes biased estimates of tree family differences over time, as slower growing families will continually be outcompeted.
Realized genetic gain trials have been established in B.C. to help corroborate estimates from progeny test designs with volume yields on a per-hectare basis. Many institutions working with fast-growing species, such as Douglas-fir and radiata pine, now have very good measures of yield-per-hectare from commercially well-known clones or families.
In B.C., realized genetic gain trials currently exist for Douglas-fir, western hemlock, western larch, lodgepole pine and interior spruce. These trials range from seven to 20 years in age. Results for age 12 in Douglas-fir have been reported, but more meaningful results from these trails will occur when the trees start to compete with more mortality, over age 20.