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

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growth
Abstract: Organic matter and N were added to humus pools of the LINKAGES simulator
of forest growth and N cycling at a range of application rates to investigate long-term effects of
biosolids (sewage sludge) on forest productivity. The simulation was done for 2 conifer
plantations (Douglas fir, Pseudotsuga menziesii var. menziesii on the coast range of Washington
state, USA; and loblolly pine, Pinus taeda on the Piedmont soils of Georgia) and a northern
hardwood forest located in New Hampshire. Single applications of biosolids were given at 0, 5,
10, 20, and 40 Mg/ha, and multiple applications on 7 occasions at 3-yr intervals at rates of 5 and
10 Mg/ha. Highly significant increases in aboveground phytomass and net primary productivity
of Douglas fir plantations were obtained in a 100-yr simulation with increasing biosolids
application rates. Results for loblolly pine from a 50-yr simulation produced about half the
growth response of Douglas fir. Long-term simulations of northern hardwoods showed modest
growth responses and small increases in NPP (net primary productivity) with added biosolids.
The phytomass of one overstorey and 3 understorey species in the hardwood forest changed in
response to different biosolids applications and varying species sensitivity to N supply. It is
concluded that biosolids are a significant resource for enhancing forest productivity, particularly
in conifer plantations. Estimates of N leaching losses from simulated forest sites combined with a
literature review of leaching losses suggest that biosolids applications at 3-yr intervals with rates
less than 8.5 Mg/ha (0.4 Mg N/ha) during active forest growth may pose little off-site
contamination risk to ground water or surface waters.
353. MacDonald, J.E. 1996. Early development of bud dormancy in conifer seedlings. In Plantdormancy:-physiology,-biochemistry-and-molecular-biology
Ed. G.A. Lang. Wallingford, UK:
CAB INTERNATIONAL. pp. 193-199.
Keywords: nursery operations
tree phenology
Abstract: A study is reported on 1-yr-old coastal Douglas fir (Pseudotsuga menziesii var.
menziesii) nursery seedlings on Vancouver Island, British Columbia, with the aim of determining
whether there was a difference in dormancy development in response to short-day or moderate
moisture stress treatments. Successful dormancy induction was obtained during the first week of
both types of treatment, but the phenology of dormancy development was different, being earlier
in the short-day treatment. Of the short-day treatments tested (3-6 wk), dormancy development
was earliest for the 4-wk duration.
354. Magnussen, S. and F.C. Sorensen. 1991. Outliers in forest genetics trials: an example of analysis
with truncated data. Scandinavian-Journal-of-Forest-Research 6(3): 335-352.
Keywords: genetic tree improvement
genetic relationships
Abstract: Previously published data for distribution of height in a Douglas fir (Pseudotsuga
menziesii) progeny trial in the Oregon Cascades with open (wind) pollinated (OP) and control
pollinated (CP) progenies showed an excess of short trees, especially in OP (inbred) progeny,
compared with a normally distributed population. Short trees had a disproportionate influence on
variance components and heritability estimates. Data truncation of potential outliers was carried
out with varying intensity in order to investigate its influence on genetic parameter estimates.
Truncation was done by either fixed threshold values or by a proportional elimination of trees
from below. Truncated data was analysed either directly or subsequent to a maximum likelihood