The relationship of tree height and crown class to the induced plant defenses of loblolly pine

1987 ◽  
Vol 65 (10) ◽  
pp. 2090-2092 ◽  
Author(s):  
T. D. Paine ◽  
F. M. Stephen

Loblolly pines, Pinus taeda L., were inoculated with a fungus associated with the southern pine beetle, Dendroctonus frontalis Zimm., at three heights to determine whether the trees responded to infection differently at each height. Loblolly pines responded to inoculation of this fungus by producing lesions of various dimensions. These were dissected and weighed. Lesions had the same weight at all three heights up the stem. However, the extent (or intensity) of reaction to fungal infection and wounding varied as a function of crown class of the tree. The influence of site quality on induced defenses may be assessed using this technique.

1976 ◽  
Vol 108 (4) ◽  
pp. 353-362 ◽  
Author(s):  
Robert N. Coulson ◽  
Adil M. Mayyasi ◽  
J. L. Foltz ◽  
F. P. Hain ◽  
W. C. Martin

AbstractThe process of resource utilization by Dendroctonus frontalis Zimmerman attacking loblolly pine, Pinus taeda L., was investigated. The quantitative relationship of attacking parent adult D. frontalis as a function of the normalized infested bole height is described by the model y = Ax(1−x)eBx. Greatest attack density occurs at the mid-bole of the tree and tapers toward the top and bottom. Gallery length (and hence eggs)/100 cm2 was independent of attack density. The relationship between gallery length (or eggs) per parent adult and parent adult density is described by the exponential decay curve y = AeBx, indicating that gallery length and egg population density are controlled by a density dependent compensatory feedback process operating instantaneously. Further support for the mechanism was obtained by analyzing the gallery length per parent adult at different locations on the infested bole. The relationship is described by the model y = [AeBx]/[x(1−x)] and indicates that gallery construction and egg population per attacking beetle increase in the upper and basal portion of the bole. The result is a uniform amount of food and space per individual of the developing population.


1986 ◽  
Vol 21 (2) ◽  
pp. 114-117 ◽  
Author(s):  
D. N. Kinn

A large infestation of southern pine beetle, (Dendroctonus frontalis Zimm.), located in central Louisiana, was surveyed for the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle. Pinewood nematodes were present in 4.2 percent of 94 loblolly pine (Pinus taeda L.) trees attacked by D. frontalis and were absent from 101 unattacked trees that surrounded the infestation. Monthly sampling of this infestation revealed an increase in the incidence of nematodes as the season progressed. Samples taken from different heights on beetle infested-boles did not differ significantly in the presence of nematodes.


1993 ◽  
Vol 3 (3) ◽  
pp. 169 ◽  
Author(s):  
DD Wade

The relationship between fire-caused stem girdling and groundline diameter (GLD) in loblolly pine (Pinus taeda L.) was determined. Results of 10 experimental prescribed bums conducted across a wide range of ambient temperature conditions during both the dormant and growing season demonstrate that low-intensity backing fires (< 346 KW/m) are an effective tool to eliminate loblolly pines less than 3.8 cm (1.5 in.) GLD. Wide differences in ambient temperature at time of burning did not affect stem kill of unscorched trees in this study. Virtually all fire-caused mortality took place within four months postburn. A predictive model that explained 92% of the variation in mortality was developed to facilitate the use of fire to thin young, overcrowded loblolly pine stands in the southeastern United States. Use of this model in conjunction with a preburn stand survey allows estimation of the number and distribution of survivors prior to ignition.


1980 ◽  
Vol 4 (4) ◽  
pp. 162-165 ◽  
Author(s):  
Peter L. Lorio

Abstract By comparison with any o several stocking standards, loblolly pine (Pinus taeda L.) stands infested with southern pine beetle (Dendroctonus frontalis Zimm.) on the Kisatchie National Forest, Louisiana, were frequently overstocked. Stocking levels associated with reduced stand and tree growth and frequent intermittent water deficits also enhance successful southern pine beetle attack. Charts that help determine how well existing stocking meets management objectives are also useful for judging stand vulnerability to the southern pine beetle.


2003 ◽  
Vol 38 (4) ◽  
pp. 576-582 ◽  
Author(s):  
Robert A. Tisdale ◽  
T. Evan Nebeker ◽  
John D. Hodges

The influence of total resin flow in loblolly pine, Pinus taeda L., on initial colonization by the southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae), was investigated. Resin flow of trees was manipulated mechanically so that it followed the same pattern of decrease and near cessation as seen in trees successfully attacked by southern pine beetle. There were also intermediate treatments where resin flow was allowed to recover after near cessation. Beetles were introduced by means of mesh cages attached to the mid-bole of trees and left until the end of the longest wounding treatment. In trees where resin flow was reduced, significant increases in number of attacks, total gallery length, and length of gallery free of resin occurred.


1988 ◽  
Vol 12 (1) ◽  
pp. 33-36 ◽  
Author(s):  
William H. McKee ◽  
Larry P. Wilhite

Abstract In three separate studies on the Lower Atlantic Coastal Plain, sites were sheared, root-raked, and bedded, and phosphorus was applied. Loblolly pine (Pinus taeda L.) seedlings were planted, and nitrogen fertilizer and preemergence herbicide were applied at several different times. In all three studies, loblolly pine responded positively in height, diameter, and aboveground biomass to herbicide applied in the spring following planting. Responses to nitrogen application were inconsistent. A pronounced increase in growth was found in only one study. There, a nitrogen and a herbicide treatment interacted to give a three-fold increase in aboveground seedling biomass after one growing season. The lack of response to nitrogen in the other two studies may be attributable to low rainfall in the spring after planting and mineralization of native nitrogen from soil organic matter. South. J. Appl. For. 12(1):33-36.


1998 ◽  
Vol 28 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Boris Zeide

A new method for estimating fractal characteristics (fractal dimension and foliage density) of a single crown or its portions is developed. The proposed method operates with volume and mass of natural units of the crown, such as shoots and branches, rather than with numbers of regular cubes. Fractal dimension alone is not sufficient to describe foliage distribution in the crown because it says nothing about the density of foliage at a given point. The density is defined as the ratio of foliage mass to fractal volume it occupies. Fortunately, the intercept of the regression, which contains fractal dimension as the slope, provides a measure of foliage density. Thus the method makes it possible to separate purely spatial factors represented by fractal dimension from ecophysiological effects characterized by foliage density. Application of the method showed that neither fractal dimension nor foliage density of the studied loblolly pines (Pinus taeda L.) correlates with current diameter increment. At the same time, there is a pronounced negative correlation between fractal dimension and crown size. These results suggest that as crowns become larger, the amount of foliage located at the crown periphery increases in proportion to the foliage amount inside the crown. As a spin-off of this analysis, a method for estimating relative foliage density (defined as the ratio of actual to maximal foliage mass for a given branch) is developed.


1981 ◽  
Vol 113 (9) ◽  
pp. 807-811 ◽  
Author(s):  
Richard A. Goyer ◽  
Michael T. Smith

AbstractUnder laboratory conditions, Corticeus glaber (LeConte) and C. parallelus (Melsheimer) adults were facultative predators of southern pine beetle, Dendroctonus frontalis Zimmermann, eggs and first and second instar larvae. Southern pine beetle frass and blue stain fungus, Ceratocystis minor (Hedgecock) Hunt were also suitable for survival for both species of Corticeus. Loblolly pine (Pinus taeda L.) phloem was not utilized as a food source by either species. Corticeus spp. larvae were predators of D. frontalis eggs.


1987 ◽  
Vol 17 (6) ◽  
pp. 569-571 ◽  
Author(s):  
T. D. Paine ◽  
F. M. Stephen

Even-aged loblolly pines growing in plantations on different sites were inoculated with Ceratocystisminor, a fungus associated with the southern pine beetle, to determine if the inducible defense system of the trees was affected by plant quality or growing conditions. Overtopped trees produced smaller hypersensitive lesions than dominant or codominant trees. There was no discernible effect of previous exposure to the fungi on the subsequent ability of the tree to respond to inoculation. A temporal effect was observed in trees growing on the better well-drained site but was not seen in trees on the poorer site with waterlogged soil.


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