SIZES, DISTRIBUTIONS, AND NUMBERS OF VERTICAL RESIN DUCTS IN LODGEPOLE PINE

1966 ◽  
Vol 44 (4) ◽  
pp. 519-525 ◽  
Author(s):  
R. W. Reid ◽  
J. A. Watson
Keyword(s):  
Radial Growth ◽  
Photographic Method ◽  
Direct Relation ◽  
Growth Rings ◽  
Resin Ducts ◽  
Resin Duct ◽  
Large Numbers ◽  
Summer Temperatures ◽  
One Year ◽  
Pinns Contorta

Methods are described for easy detection of vertical resin ducts in Pinns contorta Dougl. var. latifolia Engelm. Also a photographic method for determining the area and circumference of growth rings is described. The time of vertical resin duct formation was the same in both slow- and fast-growing trees. Vertical ducts seldom occurred in radial alignment in consecutive years. The diameters of vertical ducts varied from 60 to 105 μ and were least near the pith; lengths ranged from 3.8 to 43.2 cm in a 75-year-old tree and 1.2 to 12.0 cm in a 30-year-old tree. Wide variations occurred in the abundance of vertical ducts between years. Their presence in large numbers in one year appeared to influence their abundance in the following year. The fluctuations in number occurred simultaneously in all trees examined. Radial growth was not associated with these fluctuations. There was circumstantial evidence for a direct relation between high summer temperatures, large cone crops, and large numbers of vertical ducts.

Effects of Weevil Feeding on Resin Duct Density and Radial Increment in Lodgepole Pine

1972 ◽  
Vol 2 (1) ◽  
pp. 11-15 ◽  
Author(s):  
H. F. Cerezke
Keyword(s):  
Radial Growth ◽  
Lodgepole Pine ◽  
Radial Increment ◽  
Resin Ducts ◽  
Resin Duct ◽  
Traumatic Resin Ducts

Wood discs cut from 23-year-old lodgepole pine (Pinuscontorta Dougl. var. lalifolia Engelm.) stems were analyzed for vertical and radial resin duct densities adjacent to basal injuries caused by the weevil, Hylobiuswarreni Wood. The injury from single attacks continued for at least 2 years and was characterized by reduced radial growth and an abundance of vertical 'traumatic' resin ducts above the wounds. No increase in radial duct density was detected above the wounds.

Public Policy Administration

1985 ◽  
Vol 47 ◽  
pp. 1-16
Author(s):  
Richard A. Brumback
Keyword(s):  
Rhode Island ◽  
General Level ◽  
American Government ◽  
Introductory Course ◽  
The Past ◽  
Business Colleges ◽  
Business College ◽  
Large Numbers ◽  
The Subject ◽  
One Year

The teaching of an introductory course in American Government can be a difficult and frustrating endeavor under even the best of circumstances. Given the general level of cynicism and/or lack of interest by large numbers of Americans regarding politics and politicians, the task of generating student enthusiasm, or even mild interest, toward the subject matter can indeed be an arduous one. When the teaching of such a course takes place in a business college, and when the student audience is “captive” to a college requirement that all students must take the course, the task can be rendered considerably more formidable.For the past six years I have been teaching such courses at business colleges — one year at Bryant College in Rhode Island, and the following five years at Bentley College in Massachusetts.

Impacts of fire radiative flux on mature Pinus ponderosa growth and vulnerability to secondary mortality agents

2017 ◽  
Vol 26 (1) ◽  
pp. 95 ◽  
Author(s):  
Aaron M. Sparks ◽  
Alistair M. S. Smith ◽  
Alan F. Talhelm ◽  
Crystal A. Kolden ◽  
Kara M. Yedinak ◽  
...  
Keyword(s):  
Dose Response ◽  
Pinus Ponderosa ◽  
Radial Growth ◽  
Unit Area ◽  
Radiative Energy ◽  
Fire Intensity ◽  
Response Relationship ◽  
Fire Behaviour ◽  
Dose Response Relationship ◽  
Resin Duct

Recent studies have highlighted the potential of linking fire behaviour to plant ecophysiology as an improved route to characterising severity, but research to date has been limited to laboratory-scale investigations. Fine-scale fire behaviour during prescribed fires has been identified as a strong predictor of post-fire tree recovery and growth, but most studies report these metrics averaged over the entire fire. Previous research has found inconsistent effects of low-intensity fire on mature Pinus ponderosa growth. In this study, fire behaviour was quantified at the tree scale and compared with post-fire radial growth and axial resin duct defences. Results show a clear dose–response relationship between peak fire radiative power per unit area (W m–2) and post-fire Pinus ponderosa radial growth. Unlike in previous laboratory research on seedlings, there was no dose–response relationship observed between fire radiative energy per unit area (J m–2) and post-fire mature tree growth in the surviving trees. These results may suggest that post-fire impacts on growth of surviving seedlings and mature trees require other modes of heat transfer to impact plant canopies. This study demonstrates that increased resin duct defence is induced regardless of fire intensity, which may decrease Pinus ponderosa vulnerability to secondary mortality agents.

THE SUPPRESSION OF GROWTH RINGS IN JACK PINE IN RELATION TO DEFOLIATION BY THE SWAINE JACK-PINE SAWFLY

1963 ◽  
Vol 41 (2) ◽  
pp. 227-235 ◽  
Author(s):  
L. C. O'Neil
Keyword(s):  
Pinus Banksiana ◽  
Radial Growth ◽  
Jack Pine ◽  
Growth Rings ◽  
Cross Sectional ◽  
Pine Sawfly ◽  
Young Stand ◽  
The Dead ◽  
Dense Stand

An investigation of the radial growth of jack pine (Pinus banksiana Lamb.) defoliated by the Swaine jack-pine sawfly (Neodiprion swainei Midd.) disclosed that growth rings were discontinuous and missing in cross-sectional disks from severely damaged trees. In young and open-grown trees with dead tops, the incidence of such deficiencies in radial growth was especially high in disks from upper regions of the stems, in the vicinity of the dead tops; radial growth was suspended for 1 year and subsequently resumed in disks from the lower regions of some stems. Cambial inactivity was more generalized in trees from an old and dense stand and it was detected in disks representing major portions of some of the stems sampled; the death of some trees followed 2 to 6 years of cambial inactivity in disks cut at various heights along their entire stems. Growth deficiencies in the young stand were clearly effects of severe sawfly defoliation. Data from the old, dense stand indicated that sawfly defoliation had perhaps merely hastened the gradual deterioration of the stand in which intertree competition was intense.

scholarly journals Is the Responsiveness to Light Related to the Differences in Stem Straightness among Populations of Pinus pinaster?

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 383
Author(s):  
Rosario Sierra-de-Grado ◽  
Valentín Pando ◽  
Pablo Martínez-Zurimendi ◽  
Bruno Moulia
Keyword(s):  
Cross Sections ◽  
Pinus Pinaster ◽  
Radial Growth ◽  
Wood Quality ◽  
Secondary Growth ◽  
Natural Populations ◽  
Ecological Features ◽  
Stem Straightness ◽  
One Year ◽  
Stem Curvature

Stem straightness is related to wood quality and yield. Although important genetic differences in stem straightness among the natural populations of Pinus pinaster are well established, the main drivers of these differences are not well known. Since the responses of trees to light are key ecological features that induce stem curvature, we hypothesized that populations with better straightness should exhibit lower photomorphogenetic and phototropic sensitivity. We compared three populations to identify the main processes driven by primary and secondary growth that explain their differences in response to light. One-year-old seedlings were grown under two treatments—direct sunlight and lateral light plus shade—for a period of 5 months. The length and the leaning of the stems were measured weekly. The asymmetry of radial growth and compression wood (CW) formation were analyzed in cross-sections. We found differences among the populations in photomorphogenetic and phototropic reactions. However, the population with straighter stems was not characterized by reduced sensitivity to light. Photo(gravi)tropic responses driven by primary growth and gravitropic responses driven by secondary growth explained the kinetics of the stem leaning and CW pattern. Asymmetric radial growth and CW formation did not contribute to the phototropic reactions.

scholarly journals Dwarf Mistletoe Infection Interacts with Tree Growth Rate to Produce Opposing Direct and Indirect Effects on Resin Duct Defenses in Lodgepole Pine

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 222 ◽  
Author(s):  
Scott Ferrenberg
Keyword(s):  
Growth Rate ◽  
Natural Enemies ◽  
Indirect Effects ◽  
Annual Ring ◽  
Annual Growth ◽  
Tree Age ◽  
Direct And Indirect Effects ◽  
Dwarf Mistletoe ◽  
Resin Ducts ◽  
Resin Duct

Research Highlights: I sought to disentangle the influences of tree age, growth rate, and dwarf mistletoe infection on resin duct defenses in lodgepole pine, Pinus contorta Douglas ex Loudon, revealing the presence of direct positive and indirect negative effects of mistletoe on defenses. Background and Objectives: For protection against natural enemies, pines produce and store oleoresin (resin) in ‘resin ducts’ that occur throughout the tree. Dwarf mistletoe, Arceuthobium americanum Nutt. ex Engelm. (hereafter “mistletoe”), is a widespread parasitic plant affecting the pines of western North America. Infection by mistletoe can suppress pine growth and increase the probability of insect attack—possibly due to a reduction in resin duct defenses or in the potency of chemical defenses at higher levels of mistletoe infection, as reported in Pinus banksiana Lamb. However, the influence of mistletoe infection on defenses in other pine species remains unclear. I hypothesized that mistletoe infection would induce greater resin duct defenses in P. contorta while simultaneously suppressing annual growth, which was expected to reduce defenses. Materials and Methods: Using increment cores from P. contorta trees occurring in a subalpine forest of Colorado, USA, I quantified tree age, annual growth, annual resin duct production (#/annual ring), and cross-sectional area (mm2 of resin ducts/annual ring). Results: Mistletoe infection increased with tree age and had a direct positive relationship with resin duct defenses. However, mistletoe infection also had an indirect negative influence on defenses via the suppression of annual growth. Conclusions: Through the combined direct and indirect effects, mistletoe infection had a net positive impact on resin duct production but a net negative impact on the total resin duct area. This finding highlights the complexity of pine defense responses to natural enemies and that future work is needed to understand how these responses influence overall levels of resistance and the risk of mortality.

scholarly journals Site and Stand Conditions Associated with Pine False Webworm Populations and Damage in Mature Eastern White Pine Plantations

2007 ◽  
Vol 24 (3) ◽  
pp. 168-176 ◽  
Author(s):  
Albert E. Mayfield ◽  
Douglas C. Allen ◽  
Russell D. Briggs
Keyword(s):  
New York ◽  
Radial Growth ◽  
New York State ◽  
Fine Sand ◽  
White Pine ◽  
Eastern White Pine ◽  
Growth Rings ◽  
Soil Carbon Content ◽  
Pine False Webworm ◽  
Stand Conditions

Abstract The influence of site and stand conditions on pine false webworm (Acantholyda erythrocephala [L.], Hymenoptera: Pamphiliidae) population densities and host damage was evaluated in 22 eastern white pine (Pinus strobus L.) stands in northern New York State. Mean pine false webworm density was positively related to stand size (ha) and inversely related to soil silt content (A-horizon) after holding stand size constant. Percent radial growth loss (during the first five years after defoliation began) was inversely related to soil carbon content (B-horizon) and inversely related to fine sand content (A-horizon) after holding B-horizon carbon constant. Severe radial growth suppression (missing or discontinuous growth rings) and white pine mortality were inversely related to live crown ratio. The frequency of trees with missing growth rings was inversely related to soil nitrogen (A-horizon) after holding live crown ratio constant. Stands located on sandy glacial lake shoreline/delta deposits had more coarsely textured soils with lower levels of organic matter and nitrogen and had slower height growth rates, lower tree diversity, greater relative dominance of white pine, and higher levels of pine false webworm defoliation than stands on adjacent landforms. These results may be useful to foresters managing eastern white pine stands in areas where similar site and stand conditions predominate and pine false webworm occurs.

Relationship between leader morphology and resistance or susceptibility of Sitka spruce to the white pine weevil

1994 ◽  
Vol 24 (4) ◽  
pp. 810-816 ◽  
Author(s):  
E.S. Tomlin ◽  
J.H. Borden
Keyword(s):  
Resistance Mechanism ◽  
Selection Criterion ◽  
Sitka Spruce ◽  
White Pine ◽  
Pine Weevil ◽  
Resin Ducts ◽  
Queen Charlotte Islands ◽  
Large Numbers ◽  
Low Incidence ◽  
White Pine Weevil

Sitka spruce, Piceasitchensis (Bong.) Carr., from 27 provenances and five sites in British Columbia, were examined for traits of leader morphology that might be involved in resistance to the white pine weevil, Pissodesstrobi (Peck). Trees from the Usk Ferry provenance at Head Bay and the Kitwanga provenance at Nass River both had low incidence of weevilling, and had needles pressed more closely against the stems by up to 20° than trees from other provenances. At Fair Harbour, trees from the two most resistant provenances, Haney and Cedarvale, had inner resin ducts that were approximately twice the diameter of those in trees from the most susceptible provenances. Resistant trees from these two provenances also had significantly more outer resin ducts than those from any other provenance planted at any of the five sites. Values ranged from 28 outer ducts per centimetre for Haney trees, to <1 per centimetre for very susceptible trees from the Masset Sound provenance in the Queen Charlotte Islands, where the absence of weevils could have eliminated any selection for trees with a high density of resin ducts. We hypothesize that trees from the Haney and Cedarvale provenances may have large numbers of outer resin ducts as an important resistance mechanism, which could be used as a selection criterion for resistance. Resistant trees from other provenances such as Big Qualicum, Kitwanga, and Green Timbers, which have fewer outer resin ducts than those from Haney and Cedarvale, must rely heavily on mechanisms other than those associated with the resin system morphology.

Ontogenèse des canaux sécréteurs d'origine primaire dans la jeune plante de Pinus pinaster

1990 ◽  
Vol 68 (10) ◽  
pp. 2119-2126
Author(s):  
J. Charon ◽  
E. Vindt-Balguerie ◽  
J. Launay
Keyword(s):  
Key Words ◽  
Pinus Pinaster ◽  
Cotyledonary Node ◽  
Long Distance ◽  
Resin Ducts ◽  
Resin Duct ◽  
Pinus Pinaster Ait ◽  
Adult Plants

An ontogenic study of the primary resin ducts was carried out from the embryo to the 2-month-old seedlings stage in Pinus pinaster Ait. and revealed two separate systems, the hypocotyl-radicular ducts and the epicotylar ducts. In the first system, each one of the resin ducts, which are numerically equal to the protoxylem strands of the radicle, is formed by vertical juxtaposition of two canals initiated partly in the hypocotyl and in the radicle. This system is closed at the level of the cotyledonary node. The second system consists of the anastomosis of the resin ducts initiated in the base of euphylls. This system is closed at the level of the base of the epicotyl and is not correlated with the first one. The primary resin ducts are formed on a schizolysigenous pattern. In the epicotylar bud, the schizogenous and lysigenous processes are described and they occur over a long distance. This schizolysigenous process of primary resin ducts is compared in young and adult plants. Key words: resin duct, ontogenesis, schizogeny, lysigeny, seedling, Pinus pinaster.

Missing growth rings at the trunk base in suppressed balsam fir saplings

2002 ◽  
Vol 32 (10) ◽  
pp. 1776-1783 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Radial Growth ◽  
Adventitious Roots ◽  
Abies Balsamea ◽  
Dry Mass ◽  
Balsam Fir ◽  
Leaf Biomass ◽  
Growth Rings ◽  
Terminal Bud ◽  
Below Ground ◽  
Age Estimates

Numerous researchers have suggested a causal relationship between low leaf biomass in suppressed trees and the lack of radial growth at the base of the trunk. The objective of this study was to verify this relationship with suppressed balsam fir (Abies balsamea (L.) Mill.) saplings found growing in an old-growth fir stand. A total of 29 saplings varying in height from 67 to 183 cm were uprooted. All saplings had adventitious roots. All terminal bud scars (TBS) found between the apex of the terminal leader and the trunk base (first adventitious root) as well as those found below ground were localized, and rings were counted between TBS along the aboveground trunk. Various morphological traits and the ratio of photosynthetic tissue dry mass (P, needles) to non-photosynthetic tissue dry mass (nP, aboveground stem) were used as an indicator of tree vigour. Between 3 and 33 rings counted along the aboveground trunk were missing at the trunk base. The number of missing rings at the base of the trunk was correlated with total height (r = 0.41), height growth (r = –0.51), radial growth (r = –0.44), the P/nP ratio (r = –0.73), and the proportion of live crown (r = –0.62). Moreover, from 2 to 35 additional rings, missing at the trunk base, were found in the belowground section of trunk and these missing rings were associated with the adventitious roots phenomenon. In conclusion, suppressed firs had missing rings at the base of the trunk. When all of the missing rings were added to the number of rings counted at the base of the trunk, age estimates provided a different temporal pattern of recruitment compared with that obtained by solely counting rings at the base of the trunk. Stem analysis on the entire trunk is the best aging method for suppressed balsam fir saplings.

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