IntensIve sIlvIculture - Forest Science Labs - Research Network ...

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had significantly more mycorrhizal types than those treated with DCPA or bifenox (but were
n.s.d. from controls).
619. Trofymow, J.A., H.J. Barclay and K.M. McCullough. 1991. Annual rates and elemental
concentrations of litter fall in thinned and fertilized Douglas-fir. Canadian-Journal-of-Forest-
Research 21(11): 1601-1615.
Keywords: fertilization
thinning
soil properties
Abstract: Overstorey litterfall (primarily needles) was collected for 15 years (1972-86)
within control and treated plots in a Douglas fir (Pseudotsuga menziesii) stand near Shawnigan
Lake, British Columbia. Treated plots were thinned or fertilized, or both. Thinned plots had twothirds
of their basal area removed; fertilized plots were treated with 448 kg N/ha of either urea or
ammonium nitrate, and the fertilized plots were refertilized at the same rate 9 years later. The
annual rate of litterfall in control plots averaged 1890 kg/ha. In control plots, significant yearly
variations were observed in litterfall mass and concentrations of K, Mg, and Ca but not N or P.
Thinning decreased rates of litterfall by 80%, but rates returned to control-plot levels after 13-15
years in unfertilized plots and after 8-10 years in fertilized plots. Fertilizer treatment without
thinning depressed litterfall in the year of treatment but increased the rate by 20-80% in
subsequent years. Litterfall N concentrations increased by 40-80% the year of fertilizer treatment
and then began decreasing 3-6 years later. Nitrogen fertilization reduced litterfall P, K and Mg
concentrations for 8, 4 and 1 year(s), respectively, following fertilizer treatment. The effects were
greater in ammonium nitrate plots than in urea plots. Rates of litterfall correlated poorly with
stand density but well with basal area and stemwood increment. Correlations with the latter two
variables varied with time and treatment.
620. Trotter, D.B. and G.M. Shrimpton. 1989. Oxyfluorfen (Goal) trials with bareroot forest seedlings
in British Columbia 1987. B.C. Ministry of Forestry FRDA Report 092. vi + 22 p.
Keywords: nursery operations
tree/stand health
stand conditions
Abstract: Oxyfluorfen was evaluated at various rates for weed control and crop tolerance
on 1+0 and 2+0 bare rooted seedlings of Douglas fir (Pseudotsuga menziesii) and lodgepole pine
(Pinus contorta) at Surrey Nursery, British Columbia.
621. Tung, C.H., J. Batdorff and D.R. DeYoe. 1986a. Survival and growth of Douglas-fir seedlings
with spot-spraying, mulching and root-dipping. Western-Journal-of-Applied-Forestry 1(4): 108-
111.
Keywords: nursery operations
release treatments
chemical release
manual release
tree/stand health
growth