© 2004 Heron Publishing—Victoria, Canada
Growth response and sapwood hydraulic properties of young lodgepole pine following repeated fertilization
Isaac G. Amponsah (1, 2, 3), Victor J. Lieffers (1), Philip G. Comeau (1) and Robert P. Brockley (4)
1. Centre for Enhanced Forest Management, Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building,
Edmonton, AB, T6G 2E3, Canada / 2. Corresponding author (iamponsa@nrcan.gc.ca) / 3. Canadian Forest Service, Natural Resources Canada, Great Lakes Forestry Centre, Sault Ste. Marie, ON, P6A 2E5, Canada / 4. British Columbia Ministry of Forests, 3401 Reservoir Road, Vernon, BC, V1B 2C7, Canada / Received August 13, 2003; accepted February 15, 2004; published online August 2, 2004
Summary
We examined how tree growth and hydraulic properties of branches and boles are influenced by periodic (about 6 years) and
annual fertilization in two juvenile lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stands in the interior of British Columbia, Canada. Mean basal area (BA), diameter at breast height (DBH) and height
increments and percent earlywood and sapwood hydraulic parameters of branches and boles were measured 7 or 8 years after the
initial treatments at Sheridan Creek and Kenneth Creek. At Sheridan Creek, fertilization significantly increased BA and DBH
increments, but had no effect on height increment. At Kenneth Creek, fertilization increased BA, but fertilized trees had
significantly lower height increments than control trees. Sapwood permeability was greater in lower branches of repeatedly
fertilized trees than in those of control trees. Sapwood permeabilities of the lower branches of trees in the control, periodic
and annual treatments were 0.24 × 10–12, 0.35 × 10–12 and 0.45 × 10–12 m2 at Kenneth Creek; and 0.41 × 10–12, 0.54 × 10–12 and 0.65 × 10–12 m2 at Sheridan Creek, respectively. Annual fertilization tended to increase leaf specific conductivities and Huber values of
the lower branches of trees at both study sites. We conclude that, in trees fertilized annually, the higher flow capacity
of lower branches may reduce the availability of water to support annual growth of the leader and upper branches.
Keywords:
basal area increment, diameter increment, earlywood, height increment, leaf specific conductivity, Pinus contorta, sapwood permeability.
