Phenotypic variation in cone and needle characters of Pinus banksiana (jack pine) in northwestern Ontario

1993 ◽  
Vol 71 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Madeline L. Maley ◽  
William H. Parker

To investigate the pattern of natural variation of jack pine (Pinus banksiana Lamb.), 64 natural stands from northwestern Ontario were compared based on phenotypic variation of cone and needle morphology. Cone and needle traits were determined for 10 trees from each stand. Vegetation and soil data for the stands were determined following the procedures established by the Ontario Ministry of Natural Resources Forest Ecosystem Classification program. Climatic data for each stand were interpolated using a geographic information system based on 1951 to 1980 data for Ontario and Minnesota weather stations. Nested analyses of variance indicated that most of the variation was expressed between trees and within trees, with relatively little (1.6 – 18.9% depending on the trait) expressed between sampled populations. Discriminant analysis of cone and needle data indicated that the 64 populations generally varied longitudinally with a steep cline in the Nipigon area (ca. 88°15′W) apparent for cone data. A corresponding irregularity in the pattern of needle variation suggested that the modern pattern may be the result of separate lineages, i.e., descendents from two migration routes along eastern and western shores of Lake Superior or from two refugia. However, temperature data follows a similar pattern in this area of Ontario, and multiple regression of the discriminant analysis score means for the 64 sampled populations against elevation, climatic, and soil data indicated that much of the cone and needle variation expressed between populations could be accounted for by the regressions. Thus, the observed patterns of phenotypic variation may simply be the result of local adaptations to a variable environment. Key words: jack pine, Pinus banksiana, phenotypic variation, cone traits, needle traits, northwestern Ontario.

1995 ◽  
Vol 71 (4) ◽  
pp. 422-425 ◽  
Author(s):  
I. K. Morrison ◽  
N. W. Foster

In the spring of 1969, an experiment to test response (mean DBH, BA, BA%, and total and merchantable volume increments) to nitrogen (N), phosphorus (P) and magnesium (Mg) fertilizers, singly and in combination, was established in a semimature jack pine (Pinus banksiana Lamb.) forest on a Site Class III sandy site in the Dryden-Sioux Lookout area of northwestern Ontario, Canada. Analysis of variance of 10-year increments revealed highly significant (P = 0.01) responses of mean DBH increment, BA and percent BA increments, and total and merchantable volume increments to N, but no response to either P or Mg. An interaction between N and P was noted, however, in relation to BA and to total and merchantable volume increments. The best treatment in terms of total volume increment over that of the control was 151 kg N ha−1 plus 62 kg Mg ha−1, which produced ca. 16 m3 ha−1 of extra wood over 10 years. Key words: forest fertilization, nitrogen, phosphorus, magnesium fertilizers, jack pine growth response


1994 ◽  
Vol 70 (6) ◽  
pp. 788-794 ◽  
Author(s):  
S. C. Hills ◽  
D. M. Morris ◽  
C. Bowling

Jack pine (Pinus banksiana Lamb.) is one of the most important commercial species in northwestern Ontario and is the principal host of one of the most serious stem rusts, western gall rust (WGR) caused by Endocronartium harknessii (J.P. Moore) Y. Hirat. In 1986 a trial was established to determine, in part, effects of precommercial thinning on the distribution and occurrence of WGR in jack pine. A 9 year-old aerially seeded jack pine stand was thinned to square spacings of 1 m, 1.5 m, 2 m, 2.5 m, 3 m and a control. Fifth-year results indicated that a significant quadratic trend (p = 0.014) existed between spacing and stem gall infection rate. The incidence of WGR (stem galls) increased as stand density decreased to a maximum at 1.5 m spacing, and then declined to roughly the infection rate of the control at the lowest density (3 m). A significant relationship (0.084) between crown class and the rate of branch gall infection rate was also detected. The branch gall infection rate decreased from 6.2% year−1 for dominant trees to 2.8% year−1 for trees categorized as suppressed. Based on these results, pre-commercial thinning operations should target those trees with main stem galls and/or numerous branch galls, regardless of size and crown position, and then focus on the removal of suppressed trees to meet the desired density target. This strategy should not only enhance growth of the remaining trees, but also reduce WGR inoculum levels and reduce future WGR-related mortality. Key words: jack pine (Pinus banksiana Lamb.), western gall rust (Endocronartium harknessii (J.R Moore) Y. Hirat.), pre-commercial thinning, white pine weevil (Pissodes strobi Peck.)


1981 ◽  
Vol 57 (5) ◽  
pp. 208-211 ◽  
Author(s):  
I. K. Morrison ◽  
N. W. Foster ◽  
H. S. D. Swan

Results are reported from the third in a series of three industry-sponsored forest fertilization field trials established in an approximately 55-year-old jack pine (Pinus banksiana Lamb.) stand in the Dryden-Sioux Lookout area of northwestern Ontario. The experiment was of randomized block design and tested various combinations of N plus P and N plus K. The experiment was unique in that fertilizers were applied in the fall on approximately 5 cm of early snow. Significant increases over control for several parameters after both five and ten years were noted for several treatments. Best response in relation to total volume increment over ten years was to N at 112 kg/ha plus K at 93 kg/ha where 21.72 m3/ha of extra wood was produced.


1983 ◽  
Vol 59 (6) ◽  
pp. 308-311 ◽  
Author(s):  
H. L. Gross

The height and diameter of galled and unaffected jack pine (Pinus banksiana Lamb.) were compared for five stands in northwestern Ontario. The severity of infection by globose gall rust (Endocronartium harknessii [J.P. Moore] Y. Hirat.) was rated as the total number of galls per tree and the number of stem galls per tree.Comparison of galled with unaffected trees in all stands showed essentially no size difference. Tree size increased relative to the number of galls per tree in one of the stands. This relationship was interpreted as reflecting that large individuals had more sites susceptible to infection. Trees were more uniform in size for the other stands and no size difference associated with numbers of galls was apparent.Galls were observed on the branches but not on the main stem of trees studied in mature stands. Hence, defect associated with the merchantable portion of the bole was nil. Both stem galls and branch galls were fairly common in young stands, an indication that jack pines with stem galls usually die as stands mature. Observations in other jack pine stands indicate that galled tissue and associated tree parts frequently do die.


1977 ◽  
Vol 53 (3) ◽  
pp. 142-146 ◽  
Author(s):  
I. K. Morrison ◽  
N. W. Foster ◽  
D. A. Winston ◽  
H. S. D. Swan

Two fertilization experiments were established in a 55-year-old, relatively pure jack pine (Pinus banksiana Lamb.) stand on a Site Class III sandy site in northwestern Ontario. In both the following response variables were estimated after 10 years: mean DBH increment, BA increment (absolute and per cent) and total and merchantable volume increment. Data were analyzed by analysis of variance and Duncan's New Multiple Range Test. In the first experiment urea and ammonium nitrate at two levels of application were tested against controls. Significant increases over controls, in terms of BA and total and merchantable volume increments, occurred only with urea at 336 kg N/ha. With this treatment response was good; approximately 20 m3/ha extra merchantable wood over controls was produced over 10 years. In the second experiment N, P, and K were applied in fixed mixture, with and without lime, at five levels of application plus control. Response was generally poor with no treatment producing a statistically significant increase over control in relation to any variable. The best treatment, NPK at 1 120 kg/ha of fertilizer plus lime, produced an increase in merchantable volume over controls of less than 8 m3/ha over 10 years.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 370
Author(s):  
Holly D. Deighton ◽  
Frederick Wayne Bell ◽  
Nelson Thiffault ◽  
Eric B. Searle ◽  
Mathew Leitch ◽  
...  

We assessed 27 indicators of plant diversity, stand yield and individual crop tree responses 25 years post-treatment to determine long-term trade-offs among conifer release treatments in boreal and sub-boreal forests. This research addresses the lack of longer-term data needed by forest managers to implement more integrated vegetation management programs, supporting more informed decisions about release treatment choice. Four treatments (untreated control, motor-manual brushsaw, single aerial spray, and complete competition removal) were established at two jack pine (Pinus banksiana Lamb.) sites in Ontario, Canada. Our results suggest that plant diversity and productivity in boreal jack pine forests are significantly influenced by vegetation management treatments. Overall, release treatments did not cause a loss of diversity but benefitted stand-scale yield and individual crop tree growth, with maximum benefits occurring in more intensive release treatments. However, none of the treatments maximized all 27 indicators studied; thus, forest managers are faced with trade-offs when choosing treatments. Research on longer term effects, ideally through at least one rotation, is essential to fully understand outcomes of different vegetation management on forest diversity, stand yield, and individual crop tree responses.


1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.


1950 ◽  
Vol 82 (2) ◽  
pp. 34-43 ◽  
Author(s):  
R. R. Lejeune

The jack-pine budworm, Ohoristoneura sp., was first recorded by Graham (5, 6) as a new variety or race on jack pine. Subsequent studies by Graham (6 showed that in the early stages of their development the larvae of this insect prefer jack-pine staminate flowers as a habitat. Population records from Manitoba and northwestern Ontario indicate that infestations of the jack-pine budworm are invariably associated with an abundance of staminate flowers.


2010 ◽  
Vol 86 (6) ◽  
pp. 775-779 ◽  
Author(s):  
Alice Verrez ◽  
Dan Quiring ◽  
Thibaut Leinekugel Le Cocq ◽  
Greg Adams ◽  
Yill Sung Park

White pine weevil (Pissodes strobi Peck) damage was evaluated in one white pine (Pinus strobus L.) and four jack pine(Pinus banksiana Lamb) half-sib family test sites to determine the role of tree genotype in resistance to the weevil. Halfsibfamily explained a significant proportion of the variation in weevil attack at all sites. Estimates of family (0.16-0.54)and individual (0.09-0.24) heritabilities of jack pine resistance to white pine weevil were moderate. Estimates of family(0.37) and individual (0.22) heritability of resistance of white pine to the weevil were also moderate when the percentageof test trees damaged by the weevil was relatively low, but were insignificant four years later when more than three-quartersof trees were damaged. Significant positive correlations between mean tree height and mean incidence of trees damagedby the weevil were observed for four of seven site-years but relationships were weak, suggesting that any cost, withrespect to height growth, to breeding weevil resistant trees may be small.Key words: Pinus, Pissodes strobi, trade-offs, tree improvement, tree resistance, white pine weevil.


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