Forty-five full-sib families of Scotch pine (Pinus sylvestris L.) from an incomplete factorial mating design were planted in northeastern Kansas in 1981. The trees were evaluated in 1986 for survival, height growth, crown width, taper (crown width/height), number of stems per tree, the presence or absence of stem crooks, and the number of full faces. Needle length and needle color were measured at a consistent location on each tree in December 1987. Individual tree heritabilities were high; 49.68% for taper, 61.64% for crown width, 66.83% for height, and 71.46% for needle length. Estimated genetic gains showed that rapid improvements through selection are possible for these four traits. Combined selection consistently had the highest percentage gain and is the recommended selection procedure. Genetic correlation indicated that taper is negatively correlated with height (-0.651). Therefore, because of the commercial importance of form, selection for rapid height growth should not be the emphasis in future breeding efforts. West. J. Appl. For. 7(3):82-86.
Fractal geometry is a simple method of quantifying and describing complex shapes often found in nature (Mandelbrot 1983). The spatial arrangement of pine seedling roots is complex and not easily quantified. In this paper we report on a method for quantifying seedling roots based on concepts of fractal geometry.
Ten 1+0 bareroot seedlings of each of three grades of loblolly pine (Pinus taeda L.) were obtained from two Virginia Department of Forestry nurseries. The fractal dimension (D) was estimated for seedling roots using a computer-based box-count method. The results show that pine seedling roots have a fractal dimension, and the fractal dimension is highly correlated with root morphological traits. We propose that fractal geometry may be a new and efficient method to describe tree seedling root morphology. South. J. Appl. For. 17(3):130-134.
Germination value, seed weight, cotyledon number, cone length, date of bud set, and height growth were examined on 75 single-tree Colorado sources of blue spruce (Picea pungens Engelm.) grown under accelerated conditions in a greenhouse. The 75 sources were grouped according to seed zone of origin; and nested analysis of variance indicated significant differences between zones for all traits except cotyledon number and date of bud set. No differences were found among families (grouped according to subregions) within seed zones. Trees in families from low elevations and southern latitudes set bud later than trees of other origins. Variation in date of bud set conformed to local altitudinal clinal patterns. West. J. Appl. For. 2(4):106-109, October 1988.
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