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

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respectively. Only seedlings with large mulches were significantly larger than seedlings on small
scalps or control areas.
379. McDonald, P.M. and O.T. Helgerson. 1990. Mulches aid in regenerating California and Oregon
forests: past, present, and future. Pacific-Southwest-Research-Station, USDA-Forest-Service
General-Technical-Report PSW-GTR-123. ii + 19 p.
Keywords: release treatments
manual release
growth
Abstract: A discussion of the effects of various types of mulches for controlling seedling
environment in plantations, mostly of Pseudotsuga menziesii and Pinus ponderosa.
380. McKay, H.M. 1994. Frost hardiness and cold-storage tolerance of the root system of Picea
sitchensis, Pseudotsuga menziesii, Larix kaempferi and Pinus sylvestris bare-root seedlings.
Scandinavian-Journal-of-Forest-Research 9(3): 203-213.
Keywords: nursery operations
tree/stand protection
tree physiology
tree/stand health
Abstract: During the winter of 1990-91, fine roots of 2-year-old, undercut and wrenched
Pseudotsuga menziesii, Larix kaempferi [L. leptolepis], Pinus sylvestris, and Picea sitchensis
(Alaskan, Queen Charlotte Islands and Oregon provenances) were tested using electrolyte leakage
for frost hardiness and tolerance to storage at +1 degrees C for 30 and 90 days as excised roots.
Pseudotsuga menziesii and Pinus sylvestris showed only minor changes in root frost hardiness
with a maximum of -4 degrees C and -7 degrees C respectively. Larix leptolepis and Picea
sitchensis developed much greater root frost hardiness; L. leptolepis had a maximum hardiness of
-12 degrees C while Picea sitchensis (Queen Charlotte Islands) reached -13 degrees C during the
winter. The root frost hardiness of Picea sitchensis increased with the provenance's latitude. There
were clear species and provenance differences in the level of long-term cold-storage tolerance
attained, increasing in the order Pseudotsuga menziesii, Pinus sylvestris and Picea sitchensis
(Oregon), L. leptolepis, Picea sitchensis (Queen Charlotte Islands), and Picea sitchensis
(Alaskan). In spite of highly significant correlations between root electrolyte leakage after coldstorage
and frosting tests, root frost hardiness did not accurately indicate all aspects of long-term
cold tolerance and has limitations as a means of determining safe cold-storage dates.Tr.
381. McKay, H.M. and A.D. Milner. 2000. Species and seasonal variability in the sensitivity of
seedling conifer roots to drying and rough handling. Forestry-Oxford 73(3): 259-270.
Keywords: planting operations
tree physiology
tree/stand health
tree phenology
Abstract: The ability of the fine root system of 2-year-old bare-rooted planting stock of
Picea sitchensis of Queen Charlotte Islands (British Columbia, Canada), Oregon and Alaskan
(USA) provenances, Pseudotsuga menziesii, Larix kaempferi and Pinus sylvestris to withstand
standard drying and rough handling treatments was tested at regular intervals from September