Height growth components in inter- and intra-provenance jack pine families

1989 ◽  
Vol 19 (8) ◽  
pp. 962-972 ◽  
Author(s):  
S. Magnussen ◽  
C. W. Yeatman

Duration (D), rate of shoot elongation (RSE), number of stem units (NSU), and mean stem unit lengths (MSUL) of current year's (1987) leaders were analyzed in 18 jack pine (Pinusbanksiana Lamb.) full-sib progenies from nine inter- and nine intra-provenance crosses. The parent material consisted of selected "plus" trees from Ontario, Quebec, Wisconsin, and Michigan provenances. The average within-family variance (phenotypic) of D was on the average 186 days or twice as large as the among-family variance of 90 days. Duration was positively correlated with the number of growing degree-days at the place of parental origin. Tree height and height growth of several crosses significantly exceeded a local check lot, and the provenance effects on heights were predominantly additive (but not the luxuriance of hybrids). In determining annual height growth, it was discovered that D and RSE were roughly equally important, but large differences in RSE were observed among families with almost equal growth duration. The superior height growth of two interprovenance families was attributed to higher growth rates rather than a longer growth period. Although NSU was more important than MSUL in determining final shoot length, a negative correlation between NSU and MSUL complicated the overall significance of NSU. It was concluded that jack pine had sufficient variation in the examined height growth components to facilitate genetic improvement in height growth without adverse effects on periodicity. The provenance hybrids produced sufficiently promising results and additional exploitable phenotypic variation to warrant continued hybridization efforts.

2015 ◽  
Vol 45 (8) ◽  
pp. 970-977 ◽  
Author(s):  
Y.H. Weng ◽  
P. Lu ◽  
Q.F. Meng ◽  
M. Krasowski

Developing resistance to western gall rust (WGR) is important for maintaining healthy and productive jack pine plantations. In this study, we estimated genetic parameters of resistance to WGR and its relationship with tree height growth, based on data collected from three second-generation full-sib progeny testing series of jack pine planted in New Brunswick, Canada. Results indicated that (i) resistance to WGR in jack pine was controlled by both additive and dominance gene effects, with the latter playing a greater role; (ii) narrow-sense heritability estimates for resistance to WGR were low (mean = 0.05; series range = 0.00∼0.09), and broad-sense heritability estimates were moderate on an individual-tree basis (mean = 0.53) and considerably higher on the full-sib family mean basis (mean = 0.87); (iii) additive genetic correlation between tree height growth and WGR incidence was low (≤0.06) in two series and only slightly higher and favorable (–0.19) in one series, suggesting that selection on growth traits would not negatively affect WGR resistance; and (iv) mid-parental additive genetic and dominance effects on WGR were empirically correlated (>0.65), indicating that incorporating breeding for WGR resistance into current jack pine tree improvement programs with a seed orchard approach could partly capture the benefit from dominance effects. Although genetic gains in WGR resistance could be realized through various breeding and deployment schemes, it appeared that rapid improvement could be achieved through backward selection on full-sib family means.


1988 ◽  
Vol 18 (9) ◽  
pp. 1145-1151 ◽  
Author(s):  
S. Magnussen ◽  
C. W. Yeatman

Controlled pollinations with provenances from Petawawa (Ontario), Fife Lake (Michigan), and Big River (Saskatchewan) were made in all possible combinations, with the ensuing offspring planted at three sites along a north-south transect in Ontario. Survival at age 8 decreased with increased boreal character at the site. Survival of provenance hybrids was intermediate to that of their intraprovenance counterparts. Statistically significant heterosis (departure from midvalue of associated intraprovenance performances) was observed in tree height at two locations. At the northern-most site, growth was poor, with no significant differentiation among any of the tested full-sib families. Within-block microsite quality was unevenly distributed at two sites, which resulted in a low blocking efficiency and a highly significant among-plot variation. However, with five full-sib families per provenance cross, the impact on the statistical analysis of crosses was negligible.


1981 ◽  
Vol 11 (3) ◽  
pp. 654-661 ◽  
Author(s):  
Thomas D. Rudolph

After 4 years, inbreeding depression in tree height of jack pine (Pinusbanksiana Lamb.) was from 18 to 24% in S2 (second selfed generation) progenies compared with S0 (original female parents) open-pollinated progenies. This indicates a high degree of dominance for height growth. Crosses between S1 (first selfed generation) lines and open-pollinated progenies from S1 trees showed heterosis and relief from inbreeding depression so that vigor was restored to at least the level of the ancestral S0 parents. Genetic variance among S2 progenies was greatly increased indicating that inbreeding increased heritability of height growth.


1962 ◽  
Vol 40 (2) ◽  
pp. 273-280 ◽  
Author(s):  
L. C. O'Neil

Young jack pine (Pinus banksiana Lamb.) were defoliated manually to measure the effects of defoliation on growth of this species, and to determine the relative efficiency of foliage of different ages with respect to growth. The removal of 2-year-old or 3-year-old foliage had no appreciable effect on tree growth, but their joint removal reduced height growth. Height growth was also reduced by the removal of 1-year-old foliage. Current foliage was found essential for the maintenance of normal height, diameter, and shoot growth; in addition, its removal induced high bud mortality, the production of profuse adventitious growth, and a reduction in the rate of shoot elongation. Trees deprived of all but current foliage showed marked reductions in height, diameter, and shoot growth. Complete defoliation resulted in tree death shortly thereafter. Growth reductions resulting from some of the treatments approximated that following defoliation by the Swaine jack-pine sawfly (Neodiprion swainei Midd.). Also, the present results are compared with those obtained by several other workers in this field.


1989 ◽  
Vol 19 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Willard H. Carmean ◽  
Daniel J. Lenthall

Height-growth patterns for jack pine (Pinusbanksiana Lamb.) were studied using stem analyses from dominant and codominant trees on 141 plots in north central Ontario. All plots were in natural, well-stocked, even-aged stands 50 years of age or older. Data from 32 of the 141 plots were randomly selected to confirm results, the remaining 109 plots were used for computing the curves. Height-growth curves were developed using a five-parameter Chapman–Richards nonlinear regression that expressed height as a function of age and site index. A site-index prediction equation was also computed using a similar model that expressed site index as a function of age and tree height. Estimated site index using height-growth curves based on the 109 computation plots agreed closely with site index observed from stem analyses on the 32 confirmation plots. Major results were as follows: (i) height-growth curves based on breast-height age were more accurate than curves based on total age; (ii) polymorphic height-growth patterns were related to site index, becoming more curvilinear as site index increased; (iii) average height-growth patterns were similar for jack pine growing on four glacial landforms: shallow and deep moraines, outwashed glacial sands, and lacustrine clays and silts; and (iv) height-growth patterns for ages less than 50 years were very similar to patterns of the commonly used Plonski curves for jack pine site classes in Ontario, but after 50 years, height growth was somewhat better for all sites than predicted by the Plonski curves.


Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Olivier Fradette ◽  
Charles Marty ◽  
Pascal Tremblay ◽  
Daniel Lord ◽  
Jean-François Boucher

Allometric equations use easily measurable biometric variables to determine the aboveground and belowground biomasses of trees. Equations produced for estimating the biomass within Canadian forests at a large scale have not yet been validated for eastern Canadian boreal open woodlands (OWs), where trees experience particular environmental conditions. In this study, we harvested 167 trees from seven boreal OWs in Quebec, Canada for biomass and allometric measurements. These data show that Canadian national equations accurately predict the whole aboveground biomass for both black spruce and jack pine trees, but underestimated branches biomass, possibly owing to a particular tree morphology in OWs relative to closed-canopy stands. We therefore developed ad hoc allometric equations based on three power models including diameter at breast height (DBH) alone or in combination with tree height (H) as allometric variables. Our results show that although the inclusion of H in the model yields better fits for most tree compartments in both species, the difference is minor and does not markedly affect biomass C stocks at the stand level. Using these newly developed equations, we found that carbon stocks in afforested OWs varied markedly among sites owing to differences in tree growth and species. Nine years after afforestation, jack pine plantations had accumulated about five times more carbon than black spruce plantations (0.14 vs. 0.80 t C·ha−1), highlighting the much larger potential of jack pine for OW afforestation projects in this environment.


2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.


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