Coastal broadleaf tree breeding program
Broadleaf trees grow rapidly and provide valuable wood to value-added mills for finishing products, veneer, cabinetry, flooring and pulp. Two coastal broadleaf genetics programs were initiated in British Columbia in 1995.
B.C.'s black cottonwood genetics program started with a collection of 900 clones. The clones came from 180 provenances across the entire range of the species in B.C., Washington and Oregon.
In 2005, two field provenance-clonal trials were established with materials from the Surrey common-garden test. One site is located near Terrace and another at Red Rock, near Prince George. The two northern trials will be phased out in 2016, with the last assessment done in 2015.
A southern site at Harrison Mills was established in the spring of 2007. About 450 clones from 120 provenances were tested. The trial at Harrison Mills was abandoned in 2011 due to serious river erosion and beaver damage.
A clone bank with about 100 clones has been established at the Saanich Seed Orchard. The clones were selected based on four-year performance at Harrison Mills.
The main objectives of the initial bigleaf maple studies were to test the species’ genetic variability and potential as a plantation species.
In 1995, seeds were collected from 14 natural populations, each represented by 8 to 14 trees, throughout the species’ natural distribution in B.C. A short-term common garden test was established at the Surrey Nursery in 1996. Two long-term field tests were also established near Duncan on Vancouver Island in 1997. Severe drought at the Cowichan Valley site and heavy vegetative competition at the Crofton site resulted in high mortalities at both sites and the two trials were abandoned in 2005.
In 2008, a new test program was initiated with 43 provenances:
- 30 located in B.C.
- Four in Washington
- Four in Oregon
- Five in California
The test program has three test sites:
- Southern Vancouver Island
- Northern Vancouver Island
- Sunshine Coast
Assessments of growth and condition were conducted in 2010 and 2013. The next assessment will be done in 2017 and forward selections will be made based on the 10-year test results. A clone bank will be established at Saanich Seed Orchard with the selected materials.
- C.-Y. Xie, C. C. Ying, A. D. Yanchuk and D. L. Holowachuk. 2009. Ecotypic mode of regional differentiation caused by restricted gene migration: a case in black cottonwood (Populus trichocurpa) along the Pacific Northwest coast. Can. J. For. Res. 39: 519-526.
- C.-Y. Xie, M. R. Carlson and C. C. Ying. 2012. Ecotypic mode of regional differentiation of black cottonwood (Populus trichocurpa) due to restricted gene migration: further evidence from a field test on the northern coast of British Columbia. Can. J. For. Res. 42: 400-425.