Showing papers on "Bark published in 1982"

Studies of mineral cycling in a montane rain forest in new guinea iii. the distribution of mineral elements in the above-ground material

Abstract: SUMMARY (1) As a preliminary to studies on mineral cycling in a lower montane rain forest at about 2500 m altitude in New Guinea, estimates have been made of the amounts of six elements (N, P, K, Na, Ca and Mg) in the various fractions of above-ground material. (2) Analyses have been performed on material from nineteen fractions on a single ridge-top plot 20 x 20 m; trees of gbh > 30 cm (trunk wood, trunk bark, branches, twigs, leaves), trees of gbh 4m tall (stems, leaves), saplings and shrubs 1-4 m tall (stems, leaves), plants 1 m tall (stems, leaves), epiphytes (stems, leaves), epiphytic soil, litter and dead trunks and branches. About 2300 analyses have been carried out. (3) The concentrations of N, Ca and Mg generally increased toward the centre of the trunks of large trees, while that of P decreased; K and Na were variable. The concentrations of N, P and Mg in the wood tended to increase with height, but there were no significant trends in the bark. Intraspecific differences were considerable, and interspecific ones large. The mean concentrations of N, P, K and Mg generally increased along the series: trunk wood < branches < trunk bark < twigs < leaves. For Ca they increased along the series trunk wood < branches < leaves < twigs < trunk bark. (4) The concentrations of N, P and K in leaves fell with increasing age, but that of Ca increased and those of Na and Mg were variable. The concentrations of N, P, K and Na were not consistently different in saplings and trees of the same species, but those of Ca and Mg were higher in sapling leaves. (5) The concentrations of all six elements in small trees, saplings, seedlings and climbers varied greatly between species, but the mean values for leaves, or for stems of similar girth, were similar in all these life-forms. The vascular epiphytes differed in their consistently low foliar concentrations of N. (6) The concentrations in the epiphytic bryophytes and lichens were similar to those in epiphytic soil derived largely from them, and the concentration of N was not as low as in the vascular epiphytes. (7) Amounts in the various fractions were first calculated for the 20 x 20 m plot and, after a consideration of the likely errors, for the whole forest, for which the above-ground capital was estimated to be (in kg ha-') 850 N, 49 P, 700 K, 31 Na, 1500 Ca and 210 Mg. The distribution in four major fractions was similar for N and P, and for Ca and Mg. The relative importance of the dead material and epiphytic material with respect to N and P was much greater than suggested by their dry weight contributions. (8) The correlations between the concentrations of particular elements in different parts of the tree, and between different elements in each part of the tree have been considered for eighteen species, and possible explanations are discussed. There was no significant correlation between the leaf concentration and the trunk wood or bark concentration for N, P or K.

Phenolic glycosides of Paulownia tomentosa bark.

Abstract: The isolation of acteoside and coniferin from Paulownia tomentosa bark along with the previously reported phenolic glucoside syringin is described. The structure of both, acteoside and coniferin, have been assigned by (1)H- and (13)C-NMR spectroscopy.

Effects of pine-produced chemicals on selected understory species in aPinus ponderosa community.

Abstract: Pinus ponderosa accounted for more than 98% of all tree and shrub stratum stems in a climax community with low herb coverage and aboveground biomass, 35% and 60 g/m(2), respectively. Because of our previous report that nitrification and nitrifying bacteria in the same community were allelopathically inhibited, we speculated that the pine-produced allelochemics might also directly influence the development and growth of the herb stratum. In most cases decaying needles, needle leachate, and field soils significantly reduced germination and radicle growth ofAndropogon gerardii andA. scoparius, pine-associated herbaceous species. Additionally, growth ofAndropogon scoparius seedling radicles was reduced 28-56% by pine needle extracts, 33% by pine bark extracts, and 67% by soil hydrolysate extracts.Andropogon seed germination was reduced 20-25% by pine needles and soil. Phytotoxins identified in various plant parts and associated soils were caffeic acid, chlorogenic acid, quercetin, and condensed tannins. Pine needle water and soil hydrolysate extracts were most inhibitory to the radicle growth of the test species. Thus it appears that the limited growth of the herbaceous stratum in the pine community may be accounted for, in part, by allelopathy. Such allelopathic interactions may have an adaptive ecological significance in various forest and other plant communities.

Loss of mass and nutrient changes of decaying woody roots in lodgepole pine forests, southeastern Wyoming

Abstract: Woody root decomposition was studied in two lodgepole pine (Pinuscontorta Dougl. ex Loud. ssp. latifolia (Engelm.) Critchfield) stands in the Medicine Bow Mountains, Wyoming, from samples obtained beneath stumps that remained following: (i) partial cuttings 1–2, 5–7, 12–15, and 45 years ago, and (ii) fires that originated in the present stands 80 and 110 years ago. The specific gravity of root wood declined exponentially (mean k = 0.0415 year−1) during the first 15 years of decay. Mass-loss rates were faster for smaller (0.5–1.0 cm) than larger (2.6–5.0 cm) size classes of material, and rates were slightly faster on the site with fine textured soil than on the site with gravelly soil. Bark decay rates were not calculated due to a number of errors associated with estimating bark specific gravity. Nitrogen and calcium concentrations increased in both root wood and bark after 80 years of decay. Rapid decreases in potassium and phosphorous concentration occurred in the first 15 years of decay; however, conten...

Tissue chemistry of Abiesbalsamea and Betulapapyrifera var. cordifolia from subalpine forests of northeastern United States

Abstract: The concentrations of N, P, Ca, Mg, K, and Na are reported for leaf, twig, wood, bark, and root tissues for balsam fir (Abiesbalsamea (L.) Mill.) and heart-leaved paper birch (Betulapapyrifera var....

Bark extractives from spruce as constituents of plywood bonding agents

Abstract: The principles of the use of tannins and resins extracted from wood bark have been known since the 1950's. But only in recent years research on tannins has become lively. The literature review at the beginning of this paper concentrates mainly on the latest investigations in this field. The experimental part investigates the amount and quality of spruce bark extracts and their suitability as extenders in plywood adhesives. The use of chemically treated bark (bark dispersion) in plywood gluing is studied in the last part. If spruce bark is extracted with distilled water, the extract yield is 11.2% at the most, but when 10% of NaOH is added the yield increases to 40.0%. The extract content of drum-debarked pulpwood bark was clearly lower than that of unfloated logs, debarked in the sawmill. The results obtained reinforce the earlier belief that spruce bark extract can substitute Quebracho as an extender for plywood adhesives. Bark dispersion can also be used for this purpose. Exterior-grade birch plywood can be manufactured, using glues which contain spruce bark extract and dispersion. The extract and dispersion can also substitute part of the phenolic resin in the glue mixture, up to 20% at best, without any deterioration in the quality of gluing.

Analysis of carbohydrates in the jute plant (Corchorus capsularis)

Abstract: Jute plants (Corchorus capsularis) were fractionated into bark and stick. Jute fibre was produced from the bark by retting in water. Polysaccharides and lignin (estimated as Klason lignin) were the major constituents of the three jute fractions. Glucose, fructose, sucrose, six low-molecular weight sugar alcohols (glycerol, erythritol, threitol, rhamnitol, arabinitol, and mannitol), and two inositols (myo-inositol and scyllitol) were identified and quantified in the bark; all these compounds, except rhamnitol were also measured in the stick. Cellulose, xylans and pectins were major polysaccharide constituents in the three jute fractions. During fibre production by retting, extractives and pectic polysaccharides were solubilised or degraded, producing a fibre material enriched in cellulose and xylans.