Population studies of white spruce. II. Natural inbreeding and relatedness among neighboring trees

1984 ◽  
Vol 14 (6) ◽  
pp. 909-913 ◽  
Author(s):  
Y. S. Park ◽  
D. P. Fowler ◽  
J. F. Coles

Natural inbreeding and relatedness among neighboring trees were studied in several central New Brunswick populations of white spruce (Piceaglauca (Moench) Voss). Coefficients of relationship (r) were estimated by comparing the self-, neighbor-, open-, and unrelated-pollination effects on percent full seed. The estimates were 0.29 and 0.28 for neighbor and open pollinations, respectively. The effects of natural inbreeding on juvenile traits, e.g., germination and early growth, were slight while the effect on height growth increased with age at least to age 7 years. Neighboring white spruce trees growing in natural stands appear to be related at about the half-sib level (r = 0.25). Based on percent full seed, open-pollination approximates a level of inbreeding expected from trees related at a level well above that of half-sibs. Differential selection at the pre-embryo to early seedling stages results in progenies again related at the half-sib level. It is suggested that an inbreeding equilibrium exists in natural stands of white spruce and that this equilibrium approximates that expected from half-sib matings (F = 0.125). The inbreeding equilibrium is controlled, at least in part, by the frequency of lethal genes in the populations.

1984 ◽  
Vol 14 (5) ◽  
pp. 644-651 ◽  
Author(s):  
A. N. Burdett ◽  
L. J. Herring ◽  
C. F. Thompson

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.


1991 ◽  
Vol 21 (10) ◽  
pp. 1466-1474 ◽  
Author(s):  
I. S. Alemdag

Based on stem analyses, national site-index equations and height-growth equations for white spruce (Piceaglauca (Moench) Voss) were developed covering an area from the Yukon to Newfoundland. The objective was to construct a single set of curves for each relationship by combining all regions, instead of separate curves for individual provinces or regions. The results of these tests indicated that the objective could be reached without any significant loss of accuracy. In developing the equations a modified form of the Chapman–Richards function was employed, and results are presented in tabular and graphical forms.


2010 ◽  
Vol 86 (4) ◽  
pp. 444-454 ◽  
Author(s):  
Darwin Burgess ◽  
Greg Adams ◽  
Ted Needham ◽  
Craig Robinson ◽  
Rolland Gagnon

Scarification, fertilization and herbicide responses were investigated within nine years of planting black, Norway and white spruce, and jack pine seedlings in a clearcut in a mixedwood forest in New Brunswick, Canada. The study was designed as a complete, randomized block split-plot design with three replicates. Tree survival overall was 84%. Only jack pine survival improved significantly, with silvicultural treatment increasing from 51% to 78% with operational and to 82% with intensive herbicide applications, and to 84% after scarification alone. As expected, jack pine had greater early growth than spruce. Herbicide reduced competition and dramatically increased early growth of all four tree species, and scarification generally interacted with herbicide to further increase growth. Mean height at age nine increased with silvicultural treatments from 1.6 m to 4.0 m for jack pine, 1.2 m to 2.8 m for black spruce and 0.8 m to 2.2 m for Norway and white spruce. Foliar NPK nutrient concentrations generally increased after fertilization and herbicide applications, as did soil NPK availability when examined using ion exchange resins. Major plant competitors were trembling and largetooth aspen, red maple, beaked hazel and white birch. Higher competition after treatment at the New Brunswick site under more operational conditions was a key factor in lowering its tree productivity compared with a similar research study with much more aggressive competition control in northern Ontario involving both jack pine and black spruce.Key words: vegetation management, early plantation performance, seedling growth and nutrient uptake, Pinus banksiana, Picea mariana, Picea glauca, Picea abies, intensive silviculture


2007 ◽  
Vol 73 (20) ◽  
pp. 6577-6583 ◽  
Author(s):  
Josyanne Lamarche ◽  
Richard C. Hamelin

ABSTRACT Nitrogen fixation is one of the most important roles played by soil bacterial communities, as fixation supplies nitrogen to many ecosystems which are often N limited. As impacts on this functional group of bacteria might harm the ecosystem's health and reduce productivity, monitoring that particular group is important. Recently, a field trial with Bt white spruce, which constitutively expresses the Cry1Ab insecticidal toxin of Bacillus thuringiensis, was established. The Bt white spruce was shown to be resistant to spruce budworm. We investigated the possible impact of these genetically modified trees on soil nitrogen-fixing bacterial communities. The trial consisted of untransformed controls, GUS white spruce (transformed with the β-glucuronidase gene), and Bt/GUS white spruce (which constitutively expresses both the Cry1Ab toxin and β-glucuronidase) in a random design. Four years after planting, soil samples from the control and the two treatments from plantation as well as from two natural stands of white spruce were collected. Diazotroph diversity was assessed by extracting soil genomic DNA and amplifying a region of the nitrogenase reductase (nifH) gene, followed by cloning and sequencing. Analysis revealed that nitrogen-fixing communities did not differ significantly among the untransformed control, GUS white spruce, and Bt/GUS white spruce. Nevertheless, differences in diazotroph diversity were observed between white spruce trees from the plantation site and those from two natural stands, one of which grew only a few meters away from the plantation. We therefore conclude, in the absence of evidence that the presence of the B. thuringiensis cry1Ab gene had an effect on diazotroph communities, that either site and/or field preparation prior to planting seems to be more important in determining diazotroph community structure than the presence of Bt white spruce.


2001 ◽  
Vol 31 (6) ◽  
pp. 1038-1045 ◽  
Author(s):  
Jessica J Roberts ◽  
Janusz J Zwiazek

The study examined the effects of different relative humidity conditions at germination, early growth, and following cold storage on morphological and physiological characteristics of white spruce (Picea glauca (Moench) Voss) seedlings. Seedlings that were grown for 18 weeks following seed germination at the lower, 30% RH (RHinitial) treatments were shorter and had smaller stem diameters, shorter needles with more epicuticular wax, and a greater density of needles per centimetre stem, compared with the 80% RHinitial seedlings. After 18 weeks of growth under 30, 50, and 80% RH, the seedlings were hardened off, stored for 8 weeks at 3°C and planted in pots in growth chambers under 42 and 74% relative humidity (RHsubsequent). Under 74% RHsubsequent conditions, the lower RHinitial seedlings flushed sooner and had higher growth rates compared with the higher RHinitial seedlings. When the higher RHinitial seedlings were placed under 42% RHsubsequent conditions, their bud flush was delayed, and subsequent growth rates were lower compared with the lower RHinitial seedlings. When measured at 40% RH, seedlings subjected to lower RHinitial had higher net assimilation rates and stomatal conductance compared with the seedlings acclimated to higher RHinitial humidity. It was concluded that the humidity conditions present during early seedling growth following germination significantly affect their morphological and physiological characteristics during the second growth season.


1987 ◽  
Vol 11 (2) ◽  
pp. 73-76 ◽  
Author(s):  
J. W. Stringer ◽  
L. Shain ◽  
R. F. Wittwer

Abstract Nine clones of eastern cottonwood (Populus deltoides Bartr.) from different geographic sources were grown on two sites for height growth and survival percentage after 5 to 10 years. Several clones ranked as superior in Mississippi also performed well during the first 5 years of growthin Kentucky. The survival and diameter growth of some of these "superior" clones, however, was significantly less than others at 10 years. These same clones also exhibited low crown vigor and an abundance of stem cankers associated largely with Fusarium solani. Early growth induces must thereforebe used cautiously for determining long-term planting schedules. South. J. Appl. For. 11(2):73-76.


2007 ◽  
Vol 24 (4) ◽  
pp. 296-300 ◽  
Author(s):  
Yuhui Weng ◽  
Kathy Tosh ◽  
Yill Sung Park ◽  
Michele S. Fullarton

Abstract Polycross-pollinated white spruce (Picea glauca [Moench] Voss) families were evaluated in field and retrospective nursery tests in 1989, 1991, and 1992, respectively. Height growth was measured at age 10 for the field tests and at ages 1 to 6 for the retrospective nursery tests. Except for a few cases, the family mean correlations between nursery and field heights were significant for the 1989 and 1992 series, and their corresponding genetic correlations ranged from low to medium (from 0.37 to 0.74). Because of heavy noncrop competition, height growth in the 1991 nursery series showed consistently lower heritabilities and correlations with field performance compared with those of the other two series. Early nursery selection by theoretical prediction was generally efficient for the 1989 and 1992 series. Rank classification analysis indicated that application of early nursery selection should be used with caution for identifying elite families but could be used to cull inferior families or clones, apply multiple-stage selection, or perform positive assortative mating.


1973 ◽  
Vol 3 (4) ◽  
pp. 589-593 ◽  
Author(s):  
D. F. W. Pollard

Rates of needle initiation in lateral branch terminal buds averaged about six primordia per day between mid-May and mid-September in 10 provenances of white spruce. Variation among the provenances was not apparent until late September; a correlation then emerged between accumulated primordia and height growth. The correlation became increasingly strong in October. Slower growing provenances did not increase their primordia after early September.


2016 ◽  
Vol 376 ◽  
pp. 158-165 ◽  
Author(s):  
Andrew S. Nelson ◽  
Robert G. Wagner ◽  
Michael E. Day ◽  
Ivan J. Fernandez ◽  
Aaron R. Weiskittel ◽  
...  

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