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

102
growth
tree morphology
Abstract: Transplant stock was induced by applying a range of soil water contents (6, 12,
18 or 24%) to unstored and cold-stored 2-yr-old (2 + 0) bareroot Douglas fir (Pseudotsuga
menziesii) seedlings graded by root volume. Moisture stress had the greatest influence on
morphological characteristics that express transplant shock. Seedling terminal shoot growth, stem
diameter growth, and needle length increased with increased soil moisture content. In addition,
number of needles per centimeter on the terminal shoot greatly increased with increasing drought
stress. Under high drought stress, seedlings with relatively high root volumes tended to exhibit
reduced early growth, but later showed significantly increased overall growth regardless of soil
water content. In every case, seedlings grown in the driest soil had the lowest dry weight
components. Similarly, seedlings with the smallest initial root volumes had the lowest dry
weights, and those with the largest root volumes had the greatest dry weights. The results indicate
that drought stress is a cause of transplant shock, and that increased seedling root volume may
enable seedlings to avoid shock following outplanting to a specific site.
228. Haase, D.L. and R. Rose. 1994. Effects of soil water content and initial root volume on the
nutrient status of 2+0 Douglas-fir seedlings. New-Forests 8(3): 265-277.
Keywords: nursery operations
tree/stand protection
tree physiology
growth
tree morphology
Abstract: Two-year-old bareroot Douglas fir (Pseudotsuga menziesii) seedlings from a NW
Oregon provenance were graded on the basis of four root-volume categories - 5 to 8, 9 to 10, 11
to 13, and 14 to 20 cmsuperscript 3 - and transplanted into pots and subjected to one of four
moisture-stress treatments (6, 12, 18, and 24% soil water content) for 16 weeks. Macronutrient
concentrations and contents of both old (i.e. nursery-grown) and new (i.e. grown during moisture
stress treatment) foliar tissue were determined. A reduction in soil water content resulted in high
concn of phosphorus, potassium, and particularly nitrogen in both old and new foliar tissue. This
was attributed to reduced growth, translocation, metabolic activity, and nutrient requirement in
response to moisture stress. Seedlings with relatively greater root volumes exhibited higher
nutrient concn and contents, as well as increased growth. Thus, increased total root biomass per
unit of soil area with increasing seedling root volume may have resulted in greater nutrient use,
supply, uptake, and storage. It is suggested that relations between initial root volume and water
stress can be applied to nursery cultural practices in order to increase seedling adaptation to a
specific stress.
229. Haase, D.L. and R. Rose. 1998. Ten years of herbicide testing in PNW forest nurseries. In
Proceedings of the Annual Meeting of the Western Society of Weed Science, Waikoloa, Hawaii,
10-12 March, 1998. pp. 50-52.
Keywords: nursery operations
tree/stand health
Abstract: Nursery trials were conducted in Oregon in 1987-96 to investigate the level of
weed control and phytotoxicity of herbicides applied to Douglas fir (Pseudotsuga menziesii),
noble fir (Abies procera), lodgepole pine (Pinus contorta), ponderosa pine (P. ponderosa), western