Showing papers on "Bark published in 1984"

Variations in beech bark disease and its effects on species composition and structure of northern hardwood stands in central New England

Abstract: The extent of beech bark disease was examined on 41 permanent inventory plots in western Massachusetts and on 25 plots in Bartlett Experimental Forest in New Hampshire. The amounts of disease-cause...

Aggregation in Bark Beetles

Abstract: Bark beetles belong to the family Scolytidae, many species of which aggregate on their host trees and then breed in the host tissues. Aggregation is mediated by pheromones in combination with other stimuli. Some species colonize living trees, some, weakened or dying trees, and others, recently fallen timber.

Intracellular Suberin: Occurrence and Detection in Tree Bark

Abstract: A protocol is outlined for histochemical detection of intracellular suberin linings on the inner surface of the cell walls in impervious tissues of wounded and infected bark, and in bark forming rhytidome. Thin intracellular suberin linings (circa 0.5 µm) were detected in all 15 woody angiosperms examined. Intracellular suberisation was strongly associated with individual cells or cell layers (boundary zone) that displayed imperviousness with fluid diffusion tests. Tests inc1ude use of phloroglucinol + HCl and Sudan black B to selectively quench autofluorescence of lignin and suberin, respectively. Blue-violet excitation is used to enhance the Sudan IV test for suberin, cutin, and waxes.

Lignans from bark of the Olea plants. I.

Abstract: Four new lignans, (+)-1-acetoxypinoresinol [(1S, 2R, 5R, 6S)-1-acetoxy-2, 6-bis (4-hydroxy-3-methoxyphenyl)-3, 7-dioxabicyclo [3. 3. 0] octane] (1), (+)-1-hydroxypinoresinol (2), (+)-1-acetoxypinoresinol 4"-O-methyl ether (3) and (+)-1-hydroxypinoresinol 4"-O-methyl ether (4), and two known lignans, (-)-olivil (5) and (+)-cyclo-olivil (6), were isolated from the bark of Olea europaea L. (Oleaceae). Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. The lignans 1, 2 and 3 were also isolated from the bark of Olea africana MILL. (Olea europaea L. subsp. africana (MILL.) GREEN), and lignans 5 and 6 from the bark of Olea capensis L.

Discussion: Response of bark tissues to injury and infection

Abstract: Research of nonspecific defense processes in woody plants has focused on xylem. From these studies the concept of compartmentalization sensu Shigo was developed. Responses of bark to injury and inf...

Colonization of elm bark by Phomopsis oblonga.

Abstract: The high frequency of Phomopsis oblonga in elm outer bark in the north and west compared with southern Britain, enhances its potential to act as a biological control of the beetle vectors of Dutch elm disease in these areas. It is also more prevalent in the outer bark and a more active coloniser of the inner bark of wych elm than English and Wheatley elm. Thus potential disease control by P. oblonga is further increased in Wales, north and west England and Scotland where wych elm is most abundant.

Peeled Ponderosa Pine Trees: A Record of Inner Bark Utilization by Native Americans

Abstract: References by explorers, ethnologists and others to the utilization of pine (Pinus spp.) inner bark as a food indicate that some cultural groups of North American Indians may have used inner bark regularly, perhaps on an annual basis, while other groups may have used it primarily as an emergency food, such as during famine. The peeling dates and historical circumstances of one group of trees in the Gila Wilderness, New Mexico sug­ gest that these trees were probably peeled by the Gila Apache when they were very hungry. Inventory of surviving peeled trees, and dendrochronological dating of the peeling scars may help answer remaining questions about the importance and utilization patterns of pine inner bark as a food source.

Boundary-zone formation in peach bark in response to wounds and Cytospora leucostoma infection

Abstract: Seedlings of peach (Prunus persica (L.) Batsch cv. Halford) were mechanically wounded or inoculated with mycelium of Cytospora leucostoma (Pers.) Fr. Bark samples for histological study were taken from margins of visibly affected areas at varying times after treatment. Histological examination revealed that host responses to wounding and pathogen colonization were basically similar, differing only in timing and extent of responses examined. Nonspecific host responses included gum production, changes in cell wall polysaccharides, cell wall lignification, and formation of suberized impervious tissues as part of the process of necrophylactic periderm formation. The presence of the fungus was associated with inhibited differentiation of living tissues; and, as a result, host processes responsible for impervious tissue and necrophylactic periderm formation were affected adversely.

Effect of species and wood to bark ratio on pelleting of southern woods

Abstract: Six common southern hardwoods and loblolly pine were pelleted in a laboratory pellet mill. The pellet furnishes were blended to test the effect of different wood to bark ratios on pellet durability and production rate. Included was a ratio chosen to simulate the wood to bark ratio found in whole-tree chips. This furnish produced good quality pellets for all species tested. Pelleting of the pure wood of hardwoods was not successful; furnish routinely blocked the pellet mill dies. Pure pine wood, however, did produce acceptable pellets. It was noted that, as lignin and extractive content increased above a threshold level, the precentage of fines produced in a pellet durability test increased. Thus, all pine and tupelo wood/bark mixes produces high fines. This reduces the desirability of the pellets in the marketplace. Further research is necessary to confirm this relationship. This study suggests that both tree species and wood/bark ratio affect the durability of pellets and the rate with which they can be produced in a laboratory pellet mill. 9 references.

Suppressed buds embedded in the bark across the bole and the occurrence of their circular vessels in ficus religiosa

Abstract: A B S T R A C T A latitudinal suppressed bud which is embedded in the outer bark across the bole of Ficus religiosa is described. It might be very long and extend over half of the bole's circumference. The suppressed bud contains cambium which forms secondary xylem and phloem. Circular vessels and circular sieve tubes were frequently observed in the base of the bud as well as above its constriction areas. FICUS SPECIES have smooth and thick bark (Pundir, 1975;Roth, 1981).However,wehave observed latitudinal swellings on the bark surface of old trees of F. religiosa. From some of these latitudinal swellings epicormic branches sprouted. We have examined these transverse patterns across the trunk and found that the lateral swellings are suppressed buds which are embedded in the outer bark. Accordingly, the present paper describes their structure and their unusual vascular system.

Naphthoquinones of Diospyros usambarensis; their Molluscicidal and Fungicidal Activities

Abstract: The molluscicidal and fungicidal properties of DIOSPYROS USAMBARENSIS root bark have been attributed to the naphthoquinone 7-methyljuglone. In addition, the dimeric naphthoquinones isodiospyrin and mamegakinone and 2 artefacts, 2-methoxy- and 3-methoxy-7-methyljuglone have been isolated.

The biology of the oak bark beetle, Scolytus intricatus (Ratzeburg) (Coleoptera: Scolytidae), in southern England

Abstract: Scolytus intricatus (Ratz.) is a potential vector of oak wilt and is distributed throughout Europe wherever oak (Quercus) occurs. Its biology was studied in England in Monks Wood National Nature Reserve, Cambridgeshire, Alice Holt Forest, Surrey, and the New Forest, Hampshire, in 1977–83. S. intricatus was univoltine. Oviposition occurred from June to September in the bark of cut or weakened oak (Q. robur) over 5 cm in diameter. Eggs were laid in a single batch in maternal galleries cut across the grain of the cambium and phloem. The mean egg batch size was 17–36. Eggs hatched after 10–14 days, and the larvae ate the phloem and underwent five, or occasionally six, instars. The beetle overwintered as third-fifth-instar larvae, which were cold hardy and were located in cells in the phloem or outer xylem. Pupation occurred in spring, in cells in the bark or outer xylem. Emergence occurred between mid-May and mid-July and spanned a period of 3–4 weeks. The sex ratio was 1:1. Males and females differed externally by the presence of a tuft of setae on the frontal-clypeal suture of the head of the male. Newly emerged adults fed on twigs of live oak, but twig feeding was not obligatory for sexual maturation. Mating was observed during attacks on new hosts, which occurred in June-September. The eulophid Entedon ergias Wlk. was an endoparasite of larvae while larvae of the dolichopodids Medetera and Dolichopus and woodpeckers were predators.

Nitrogen-Fixing Bacteria from Warty Lenticellate Bark of a Mangrove Tree, Bruguiera gymnorrhiza (L.) Lamk

Abstract: Detached warty lenticellate bark of a mangrove tree species, Bruguiera gymnorrhiza (L.) Lamk. from Iriomote Island, Okinawa, a subtropical region of Japan, showed development of acetylene reduction activity when incubated in a mineral nutrient solution lacking nitrogen under an atmosphere consisting of 5% O(2), 90% N(2), and 5% C(2)H(2). The bacteria responsible for nitrogen fixation were isolated from the bark, and their capacity for acetylene reduction and the incorporation of N(2) into the bacterial cells was confirmed. Four representative strains of the isolates were subjected to taxonomic classification. Two strains were similar to Enterobacter cloacae, and another resembled Enterobacter aerogenes. The characteristics of the fourth strain were similar to those of Klebsiella planticola (Bagley et al., Curr. Microbiol. 6:105-109, 1981). The results of this investigation suggest that the acetylene reduction activity of lenticellate warts of mangrove trunk bark is due to the presence in the warts of nitrogen-fixing bacteria belonging to the family Enterobacteriaceae.

Bicyclic Ketals in the chemical communication of European bark beetles

Abstract: Our results confirm former observations that uncomplexed AA and analogs in the solid state adopt one and the same flat molecular shape favorized by the two strong 5 ~ 1 type hydrogen bonds and some intramolecular Hbonded water molecules regardless of the nature o f solvent and a high water content wherein the compact conformarion seems to predominate by far [10]. The conformation of AA at its carrier protein in liver cell membranes has yet to be solved.

Variation in density and moisture content of wood and bark among twenty Eucalyptus grandis progenies

Abstract: Variation in density and moisture content of Eucalyptus grandis wood and bark is described utilizing the trees established for a half-sib progeny test in southern Florida. Differences in density and moisture content among progenies were significant. Variations in wood properties were largely due to the genetic differences. No relationship was found between wood density and wood moisture content. Implications for genetic manipulation of wood quality for this species were discussed.

Root Diseases and Blister Rust Associated with Bark Beetles (Coleoptera: Scolytidae) in Western White Pine in Idaho

Abstract: Root systems of western white pine, Pinus monticola Douglas, were excavated with explosives and examined for pathogens Data were also recorded on portions of the crown killed by blister rust caused by Cronartium ribicola Fisch Statistical tests revealed a significant association between the bark beetles Dendroctonus ponderosae Hopkins and Pityogenes fossifrons (LeConte), and the root pathogen Armillariella mellea (Vahl ex Fr) Karst and between beetles and all root diseases Ninety-two percent of the trees attacked by bark beetles had root diseases, and 97% had either root diseasesor blister rust A discriminant analysis correctly classified 88% of the sample trees into two categories, trees infested with D ponderosae or trees not infested with D ponderosae, using the variables age (stump), diameter at 13 m in height, and percentage of the primary roots infected with pathogens Major pathogenic organisms isolated from the roots included A mellea, Phaeolus schweinitzii (Fr) Pat, Resinicium bicolor (Fr) Parm, Verticicladiella spp, and a Europhium strain A hypothetical sequence of host tree invasion by blister rust, followed by infection by root diseases, and finally attacks by bark beetles, is postulated

Cytotoxic Quassinoids from Odyendyea gabonensis Stem Bark: Isolation and High-Field NMR

Abstract: The stem bark of ODYENDYEA GABONENSIS Engl. (Simaroubaceae) has yielded five quassinoids, identified as ailanthinone ( 1), 2′-acetoxyglaucarubinone ( 2), glaucarubinone ( 4), 2′-acetoxyglaucarubin ( 5) and excelsin ( 6), the simple coumarin scopoletin and the alkaloid 8-hydroxycanthin-6-one ( 3). Highfield 1 H- and 13 C-NMR spectra were recorded where possible and results are tabulated.

Bark phenolics of American beech (Fagus grandifolia) in relation to the beech bark disease

Abstract: The amount of total extractable phenols was determined for bark sections obtained from behind cankers naturally induced by Nectria coccinea var. faginata and from behind mechanically inflicted wounds on stems of American beech. Healthy bark from susceptible trees was found to contain a similar level of phenolics as bark from trees determined to be resistant to the beech bark disease. Six months after wounding, wound-altered bark from susceptible trees was found to be lower in phenols than woundaltered bark from resistant trees. Inoculation of wounds with N. coccinea var. faginata resulted in decreased phenolic levels in bark sections nearest the wound surface, and increased phenolic levels in sections nearest the vascular cambium, several mm distant. Phenolic levels in injured or infected bark appear to follow similar patterns as those resulting from injury or infection of xylem tissues.

Evaluation of Possible Effects of Acid Rain on Scleroderris Canker of Red Pine in New York

Abstract: The possible affects of acid rain on Scleroderris canker of red pine were evaluated through two procedures. In the first, red pine seedling field plots, protected and unprotected from natural rain, were exposed to natural inoculum and treated with either deionized distilled water (pH 5.6), artificial acid rain (pH 3.5), or lime. Acid rain treatments did not increase disease infection levels over distilled water or lime treatments. Soil pH was slightly lowered by acid rain treatments. The second procedure evaluated pH and buffering capacity of red pine bark and buds from twelve plantations in the Adirondack region of New York. In addition, soil pH and soil cation content of the stands were determined and evaluated in relation to bark pH and natural Scleroderris canker disease increase rates. The effect of acid rain on red pine bark is probably minimal since bark surfaces were generally more acidic than acid rain. Buffering capacity against acid was small. Soil pH and spring bark surface pH were found to be inversely correlated with disease increase. These two procedures generated contrasting interpretations: (1) Scleroderris canker disease did not increase in response to artificial acid rain treatment of seedlings; (2) Scleroderris canker disease increase rate in red pine stands was somewhat related to soil pH. None of these relationships are very strong, and, therefore, it would appear that the various interacting factors of acid rain on the system generate a neutral minor impact on the Scleroderris disease problem in New York.