scholarly journals Root Deformation Reduces Tolerance of Lodgepole Pine to Attack by Warren Root Collar Weevil

2010 ◽  
Vol 39 (2) ◽  
pp. 476-483 ◽  
Author(s):  
Jeanne A. Robert ◽  
B. Staffan Lindgren
1982 ◽  
Vol 12 (4) ◽  
pp. 865-875 ◽  
Author(s):  
R. van den Driessche

Nursery sowings of coastal and interior varieties of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), Sitka spruce (Piceasitchensis (Bong) Carr), and lodgepole pine (Pinuscontorta Dougl.) were thinned to different spacings 5 weeks after germination. Spacings in the drills, which were 15 cm apart, were 1, 2, 4, 8, and 12 cm, with the nursery sowing rate (about 0.6-cm spacing) as control. Spacings were applied factorially with three levels of N fertilizer: 60, 140, and 235 kg N ha−1. Two-year-old seedlings were planted out at Campbell River (coastal Douglas-fir) and Port Alice (Sitka spruce), both on Vancouver Island, and at Lyne Creek (interior Douglas-fir) in the Cariboo region and at Fulton Lake (lodgepole pine) in the Prince Rupert region of British Columbia. Wider spacing and greater N supply increased 2-0 seedling dry weight, root-collar diameter, and shoot height and also affected distribution of dry matter between needles, stems, and roots. Wider spacing increased survival of outplanted interior Douglas-fir by 12%. Survival of coastal Douglas-fir and Sitka spruce species was high and only increased 4 to 7% due to wide spacing after one season, but after three seasons wide spacing increased survival 17 – 19%. Compared with control, 12-cm spacing increased first-season shoot growth 53% for coastal Douglas-fir, 82% for interior Douglas-fir, and 71% for Sitka spruce. Second-season shoot growth of lodgepole pine was increased 92% by the widest spacing. Much of the improved growth was explained in terms of increased seedling size. At the highest level of N supply, increasing spacing to 4 cm did not greatly reduce yield of seedlings with root-collar diameters greater than 3 mm, except for interior Douglas-fir. Thus moderate increase in spacing improved quality without materially reducing yield of seedlings per unit area of nursery. Nursery fertilization at 235 kg N ha−1 increased new-shoot growth one season after planting by 36–58% compared with the 60 kg N ha−1 level. After three seasons the effect of higher N supply was reduced to 0–42%. High N level increased survival of coastal Douglas-fir and Sitka spruce slightly, but decreased survival of interior Douglas-fir.


1974 ◽  
Vol 4 (3) ◽  
pp. 312-320 ◽  
Author(s):  
H. F. Cerezke

Leader growth and radial increment on the stem and main lateral roots during three consecutive years following partial girdling treatment were analyzed on 25- to 30-year-old lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) from a natural stand in west-central Alberta. Simulation of the larval feeding wounds of the weevil, Hylobiuswarreni Wood, consisted of the removal of a 7-mm-wide band of bark from 0% (control), 20%, 40%, 60%, 80%, and 90% of the root-collar circumference of 58 sample trees.Partial girdling reduced leader elongation and radial increment of the leader and lateral roots. Leader height decreased with increased girdling of the root-collar during each of the three post-treatment years. Below the leader, partial girdling of the root-collar did not affect radial increment in the first year, caused an increase during the second year, and a decrease in the third year. At 2 cm above the partial girdles, radial growth above the girdled side of stems was always less than that on the nongirdled side and showed a trend of increase with increased girdling on both girdled and nongirdled sides of the stem. Radial increment was considerably reduced on lateral roots extending below girdle wounds during the three post-treatment years. Two graphs are prepared which can be used to estimate height and radial increment losses in young pine stands infested by H. warreni.


1999 ◽  
Vol 131 (6) ◽  
pp. 825-827 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton ◽  
T.L. Shore

Lodgepole pines, Pinus contorta var. contorta Engelmann, killed by mountain pine beetle, Dendroctonus ponderosae Hopkins, are often subsequently infested by other scolytid species (Safranyik et al. 1996). Ips pini (Say) breeds in the phloem region of the main bole and larger branches in areas not occupied by mountain pine beetle. Adults emerge in the fall and drop to overwinter in the duff near the bases of their brood trees (Safranyik et al. 1996). Hylurgops porosus (LeConte) infests lodgepole pine (Keen 1952; Bright 1976) stumps or severely weakened trees near the root collar and in large roots (Wood 1982). We examined the pattern of emergence of I. pini and H. porosus from the duff around infested trees to describe changes in density over distance from the trees.


1991 ◽  
Vol 21 (1) ◽  
pp. 20-24 ◽  
Author(s):  
H. W. Klein-Gebbinck ◽  
P. V. Blenis ◽  
Y. Hiratsuka

Juvenile lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) were excavated at three sites near Hinton, Alberta. In all cases in which Armillariaostoyae (Romagn.) Herink had become established in the root collar or taproot, it was also able to colonize lateral roots. In cases in which only lateral roots were infected, subsequent colonization generally was primarily distal to the point of infection. Rhizomorphs were associated with 89% of 21 infected roots, whereas only 19% of 70 roots with no associated rhizomorphs were infected. Stumps, roots, and debris from the previous generation of trees were the inoculum sources for 78% of 36 infected juvenile trees, and infected regeneration served as the inoculum source for the remaining trees. Rhizomorphs occasionally were attached to the roots or rhizomes of plants other than pine, especially fireweed (Epilobiumangustifolium L.). There was no spatial relationship between stumps and symptomatic trees. Nearest neighbor analysis indicated that the likelihood of an individual tree developing symptoms was dependent on whether trees within 0.15 m were dead or dying but independent of the apparent health of trees at greater distances.


1979 ◽  
Vol 55 (3) ◽  
pp. 88-90
Author(s):  
A. K. Helium

Lodgepole pine seedlings in eight plantations established between 1972 and 1976 in west central Alberta had very similar early height growth compared with natural wildlings or seedlings which have grown on site from seed.Smaller root collar diameters, lighter seedlings, less root extension and growth, and possible development of shoot/root ratios exceeding 8.0 in planted stock later than seven years from seed germination, are the only measures to suggest that planted stock might be developing non-normal growth patterns in later years.The study showed that the planted stock maintained and increased its height-growth-lead over natural wildlings for at least four years after outplanting because of the head start in the nursery. This advantage represented an ever-decreasing part of the total seedling height and was estimated to have virtually no long-term significance because natural wildlings grew more rapidly in height than planted seedlings, year for year.


1992 ◽  
Vol 22 (2) ◽  
pp. 206-209 ◽  
Author(s):  
D.J. Bergvinson ◽  
J.H. Borden

The herbicide glyphosate was administered into the sapwood around the root collar of lodgepole pine trees, Pinuscontorta var. latifolia Engelm., to determine its effect on invasion by the blue stain fungus Ophiostomaclavigerum (Robinson-Jeffrey & R.W. Davidson) T.C. Harrington. In two experiments, lesions in the sapwood were longer and wider in trees treated with glyphosate before inoculation with O. clavigerum than in untreated, control trees. Ophiostomaclavigerum was recovered in a third experiment at seven times the distance from the point of inoculation in trees treated with glyphosate 3 weeks before inoculation as in untreated, control trees. We conclude that previously observed enhancement of brood development of the mountain pine beetle, Dendroctonusponderosae Hopk., was caused by glyphosate--induced inhibition of the trees' secondary defense response to invasion by the beetle's symbiotic fungi.


2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Sharleen L Balogh ◽  
Niklas Björklund ◽  
Dezene P W Huber ◽  
B Staffan Lindgren

Abstract Hylobius warreni Wood (Coleoptera: Curculionidae) is a pest of conifers, especially lodgepole pine (Pinus contorta var. latifolia Douglas ex Loudon) (Pinales: Pinaceae) in the Interior of British Columbia. The larvae feed on the roots and root collars and cause girdling damage, resulting in mortality or growth reductions. Previous research has suggested the adult weevils locate potential host trees by using random movements and vision, but likely not chemosensory cues. The purpose of this study is to determine if adult H. warreni respond to particular tree characteristics versus encounter potential hosts at random. Study A was a capture–mark–recapture experiment where weevils were captured on mature pine trees, while Study B was a tracking experiment within a young pine plantation. Weevils showed a preference for larger trees, and for trees that were closer to the weevil’s last known location. In Study A, weevils also avoided climbing trees in poor health, while in Study B, the weevils’ preference for taller trees increased as their distance from the weevil increased, as well as when taller trees were closer to other trees. Movement rates were similar to those observed in previous studies, were positively correlated with the average spacing of trees, and declined with time after release. This confirms previous findings that H. warreni may locate host trees by both vision and random movements, and that their movements are determined primarily by the size and distribution of potential host trees within their habitat.


1973 ◽  
Vol 3 (4) ◽  
pp. 599-601 ◽  
Author(s):  
H. F. Cerezke

Some patterns of bark thickness and bark resin cavity size, density, and their proportionate area in the inner bark on lateral roots, root-collar, and lower stem of 20–25-year-old lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) are described in relation to the oviposition and larval feeding-zone of the weevil, Hylobiuswarreni Wood. The oviposition and feeding-zone occurred where bark thickness was maximal, but where the density of cavities and their proportionate area occupied in the bark were low.


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