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effects of co2 enrichment on the photosynthetic light response of sun and shade leaves of canopy sweetgum (liquidambar styraciflua) in a forest ecosystem.to investigate whether sun and shade leaves respond differently to co2 enrichment, we examined photosynthetic light response of sun and shade leaves in canopy sweetgum (liquidambar styraciflua l.) trees growing at ambient and elevated (ambient + 200 microliters per liter) atmospheric co2 in the brookhaven national laboratory/duke university free air co2 enrichment (face) experiment. the sweetgum trees were naturally established in a 15-year-old forest dominated by loblolly pine (pinus taeda l.). ...199910562393
production efficiency of loblolly pine and sweetgum in response to four years of intensive management.we tested the hypothesis that productivity of intensively managed loblolly pine (pinus taeda l.) and sweetgum (liquidambar styraciflua l.) stands is dependent not only on leaf area, but also on foliar photosynthetic rate. effects of irrigation (irrigation treatment), irrigation with a fertilizer solution (fertigation treatment), and fertigation + pest control (loblolly pine only; fertigation + pest control treatment) on leaf physiology and growth were compared with control plots during the third ...200111282576
influence of elevated co2 and mycorrhizae on nitrogen acquisition: contrasting responses in pinus taeda and liquidambar styraciflua.an understanding of root system capacity to acquire nitrogen (n) is critical in assessing the long-term growth impact of rising atmospheric co2 concentration ([co2]) on trees and forest ecosystems. we examined the effects of mycorrhizal inoculation and elevated [co2] on root ammonium (nh4+) and nitrate (no3-) uptake capacity in sweetgum (liquidambar styraciflua l.) and loblolly pine (pinus taeda l.). mycorrhizal treatments included inoculation of seedlings with the arbuscular mycorrhizal (am) fu ...200111303652
nutritional ecology of the formosan subterranean termite (isoptera: rhinotermitidae): feeding response to commercial wood species.the feeding preferences of the formosan subterranean termite, coptotermes formosanus shiraki, were tested in three separate experiments on 28 different wood species. experiment 1 was a multiple-choice test designed to test relative preferences among 24 wood species commercially available in new orleans, la. experiment 2 was a similar study designed to test relative preferences among 21 wood species shown or reported to be unpalatable to the formosan subterranean termite. experiment 3 was a no-ch ...200111332848
insect herbivory in an intact forest understory under experimental co2 enrichment.human-induced increases in atmospheric co(2) concentration have the potential to alter the chemical composition of plant tissue, and thereby affect the amount of tissue consumed by herbivorous arthropods. at the duke forest free-air concentration enrichment (face) facility in north carolina (facts-1 research facility), we measured the amount of leaf tissue damaged by insects and other herbivorous arthropods during two growing seasons in a deciduous forest understory continuously exposed to ambie ...200414714173
long-term elevation of atmospheric co(2) concentration and the carbon exchange rates of saplings of pinus taeda l. and liquidambar styraciflua l.the relationship between carbon exchange rate (cer) and internal co(2) concentration was measured in leaves of saplings of liquidambar styraciflua l. (sweetgum) and pinus taeda l. (loblolly pine) grown from seed for more than 14 months at atmospheric co(2) concentrations of either 350 or 500 microl l(-1). an elevated concentration of co(2) during growth reduced cer at any given internal co(2) concentration in sweetgum, but not in loblolly pine. stomatal limitation of cer showed little response t ...198814972815
effects of quantum flux density on photosynthesis and chloroplast ultrastructure in tissue-cultured plantlets and seedlings of liquidambar styraciflua l. towards improved acclimatization and field survival.liquidambar styraciflua l. seedlings and tissue-cultured plantlets were grown under high, medium, or low (315, 155, or 50 microeinsteins per square meter per second photosynthetically active radiation) quantum flux densities. net photosynthesis, chlorophyll content, and chloroplast ultrastructure of leaves differentiated from these conditions were investigated. seedling photosynthetic rates at light saturation were positively related to light pretreatments, being 6.44, 4.73, and 2.75 milligrams ...198516664297
nitrogen uptake, distribution, turnover, and efficiency of use in a co2-enriched sweetgum forest.the progressive nitrogen limitation (pnl) hypothesis suggests that ecosystems in a co2-enriched atmosphere will sequester c and n in long-lived biomass and soil organic pools, thereby limiting available n and constraining the continued response of net primary productivity to elevated [co2]. here, we present a six-year record of n dynamics of a sweetgum (liquidambar styraciflua) stand exposed to elevated [co2] in the free-air co2 enrichment (face) experiment at oak ridge, tennessee, usa. we also ...200616634292
the leaf oil of liquidambar styraciflua.the leaf oil of liquidambar styraciflua was obtained by simultaneous distillation extraction and analysed by gc and gc-ms. thirty-six components, all ter-penoid, were identified, with the major constituents being terpinen-4-ol, alpha-pinene and sabinene. the high terpinen-4-ol and low 1,8-cineole content make the oil of some pharmacological interest.198917262429
phylogeny and biogeography of altingiaceae: evidence from combined analysis of five non-coding chloroplast regions.the altingiaceae consist of approximately 15 species that are disjunctly distributed in asia and north america. the genus liquidambar has been employed as a biogeographic model for studying the northern hemisphere intercontinental disjunctions. parsimony and bayesian analyses based on five non-coding chloroplast regions support that (1) liquidambar is paraphyletic; (2) the temperate liquidambar acalycina and liquidambar formosana are nested within a large tropical to subtropical asian clade; (3) ...200616439163
an isotopic method for testing the influence of leaf litter quality on carbon fluxes during decomposition.during microbial breakdown of leaf litter a fraction of the c lost by the litter is not released to the atmosphere as co(2) but remains in the soil as microbial byproducts. the amount of this fraction and the factors influencing its size are not yet clearly known. we performed a laboratory experiment to quantify the flow of c from decaying litter into the soil, by means of stable c isotopes, and tested its dependence on litter chemical properties. three sets of (13)c-depleted leaf litter (liquid ...200717665218
use of lipid composition and metabolism to examine structure and activity of estuarine detrital microflora.earlier studies have shown that the activity of the estuarine detrital microflora measured by various enzyme activities, muramic acid and adenosine 5'-triphosphate (atp) content, heterotrophic potentials, and respiratory activities correlates with the incorporation of c and p into the microbial lipids. in this study, these lipids were reproducibly fractionated into neutral lipid, glycolipid, and phospholipid classes. distinct differences between the active microflora of oak leaves, sweet gum lea ...197716345244
responses of floodplain forest species to spatially condensed gradients: a test of the flood-shade tolerance tradeoff hypothesis.previous work in southeastern us floodplains led to the hypothesis that a tradeoff between flood and shade tolerance underlies species-specific responses to flooding and light, which drive forest regeneration. in systems where community turnover can occur with small-scale environmental changes, testing this hypothesis requires recognizing that turnover of species along the two gradients can be large relative to the spatial distances involved. we test the tradeoff hypothesis in an old-growth bott ...200616187107
phloem loading. a reevaluation of the relationship between plasmodesmatal frequencies and loading strategies.the incidence of plasmodesmata in the minor vein phloem of leaves varies widely between species. on this basis, two pathways of phloem loading have been proposed: symplastic where frequencies are high, and apoplastic where they are low. however, putative symplastic-loading species fall into at least two categories. in one, the plants translocate raffinose-family oligosaccharides (rfos). in the other, the primary sugar in the phloem sap is sucrose (suc). while a thermodynamically feasible mechani ...200415516516
sucrose metabolic pathways in sweetgum and pecan seedlings.sucrose metabolism and glycolysis were studied in one- to two-year-old seedlings of sweetgum (liquidambar styraciflua l.) and pecan (curya illinoinensis (wangenh.) c. koch). the sucrose synthase pathway was identified as the dominant sucrose metabolic activity in sucrose sink tissues such as terminal buds and the root cambial zone. the sucrose synthase pathway was completely dependent on uridine diphosphate and pyrophosphate and it was activated by fructose 2,6-bisphosphate. both acid and neutra ...198914972997
responses of loblolly pine, sweetgum and crab grass roots to localized increases in nitrogen in two watering regimes.root responses to differences in availability of nitrogen and soil water were studied in loblolly pine (pinus taeda l.) seedlings grown in monoculture and in competition with sweetgum (liquidambar styraciflua l.) or crab grass (digitaria spp.). rhizotron cells were maintained at high soil water availability (approximately -0.1 mpa) or subjected to three dry-down cycles to low soil water availability (approximately -1.0 mpa), over two growing seasons. localized increases in nitrogen availability ...199614871786
pasteuria sp. parasitizing trophonema okamotoi in florida.two populations of trophonema okamotoi parasitized by pasteuria sp. were found on liquidambar styraciflua (sweetgum) and on an unidentified tropical grass in north-central florida. endospores of this pasteuria sp. attached to motile vermiform second-stage juveniles (j2) and males of t. okamotoi, but not to other developmental stages. sporangia and new endospores were produced only inside the bodies of swollen and sedentary third- and fourth-stage juveniles and females that developed in the host ...199219283199
effects of light, temperature and canopy position on net photosynthesis and isoprene emission from sweetgum (liquidambar styraciflua) leaves.in june 1993, net photosynthetic rates, stomatal conductance and isoprene emission rates of sweetgum leaves (liquidambar styraciflua l.) were measured at the top of the forest canopy (sun leaves) and within the canopy at a height of 8-10 m above ground level (shade leaves). large differences in net photosynthetic rates and stomatal conductance were found between sun and shade leaves. mean rates of isoprene emission, expressed on a leaf area basis, were significantly lower in shade leaves than in ...199614871744
isoprene emission, photosynthesis, and growth in sweetgum (liquidambar styraciflua) seedlings exposed to short- and long-term drying cycles.isoprene emissions were studied in one-year old sweetgum (liquidambar styraciflua l.) seedlings during nine drying-rewatering cycles extending over five months. each drying cycle lasted to the point of leaf wilting. growth was essentially stopped in response to the first drying cycle, though seedling survival and capacity to recover turgor on rewatering remained high throughout the entire nine cycles. photosynthetic rates of leaves were inhibited by the drying treatments. under severe drought, i ...199614871730
long- and short-term flooding effects on survival and sink-source relationships of swamp-adapted tree species.about 95% of swamp tupelo (nyssa sylvatica var. biflora (walt.) sarg.) and sweetgum (liquidambar styraciflua l.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (quercus michauxii nutt.) and cherrybark oak (q. falcata var. pagodifolia ell.) seedlings survived one year of flooding. death of oak seedlings occurred in phases associated with periods of major vegetative growth, e.g., after bud burst in spring, after summer stem elongation, a ...199614871716
liquidambar styraciflua. 200312839311
leaf dynamics of a deciduous forest canopy: no response to elevated co2.leaf area index (lai) and its seasonal dynamics are key determinants of terrestrial productivity and, therefore, of the response of ecosystems to a rising atmospheric co(2) concentration. despite the central importance of lai, there is very little evidence from which to assess how forest lai will respond to increasing [co(2)]. we assessed lai and related leaf indices of a closed-canopy deciduous forest for 4 years in 25-m-diameter plots that were exposed to ambient or elevated co(2) (542 ppm) in ...200312811536
combined effects of elevated co2 and natural climatic variation on leaf spot diseases of redbud and sweetgum trees.atmospheric co(2) concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. in this study conducted over five years, we assessed how elevated co(2) and interannual climatic variability affect cercospora leaf spot diseases of two deciduous trees. climatic data varied considerably between the five years and altered disease expression. disease incidence and severity for both species were gr ...201019679383
genotypic effects of fertilization on seedling sweetgum biomass allocation, n uptake, and n use efficiency.screening and selecting tree genotypes that are responsive to n additions and that have high nutrient use efficiencies can provide better genetic material for short-rotation plantation establishment. a pot experiment was conducted to test the hypotheses that (1) sweetgum ( liquidambar styraciflua l.) families have different patterns in biomass production and allocation, n uptake, and n use efficiency (nue), because of their differences in growth strategies, and (2) sweetgum families that are mor ...200112805877
thermal acclimation of photosynthesis: a comparison of boreal and temperate tree species along a latitudinal transect.common gardens were established along a approximately 900 km latitudinal transect to examine factors limiting geographical distributions of boreal and temperate tree species in eastern north america. boreal representatives were trembling aspen (populus tremuloides michx.) and paper birch (betula papyrifera marsh.), while temperate species were eastern cottonwood (populus deltoides bartr ex. marsh var. deltoides) and sweetgum (liquidambar styraciflua l.). the species were compared with respect to ...201020082671
isotopic evidences for microbiologically mediated and direct c input to soil compounds from three different leaf litters during their decomposition.we show the potentiality of coupling together different compound-specific isotopic analyses in a laboratory experiment, where (13)c-depleted leaf litter was incubated on a (13)c-enriched soil. the aim of our study was to identify the soil compounds where the c derived from three different litter species is retained. three (13)c-depleted leaf litter (liquidambar styraciflua l., cercis canadensis l. and pinus taeda l., delta(13)c(vspdb) approximately -43 per thousand), differing in their degradabi ...200920234880
regional assessment of ozone sensitive tree species using bioindicator plants.tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-atlantic regions of the united states. quantifying possible regional-scale impacts of ambient ozone on forest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. biomonitoring provides an approach to document direct foliar injury irrespective of direct measure of ozone uptake. we used bioindicator and field plot data from the usda forest ...200312691526
nutritional ecology of the formosan subterranean termite (isoptera: rhinotermitidae): growth and survival of incipient colonies feeding on preferred wood species.the wood of 11 plant species was evaluated as a food source significantly impacting the growth and survival of incipient colonies of the formosan subterranean termite, coptotermes formosanus shiraki (isoptera: rhinotermitidae). colonies of c. formosanus feeding on pecan, carya illinoensis (wangenh.), and red gum, liquidambar styraciflua l., produced significantly more progeny than colonies feeding on other wood species tested. progeny of colonies feeding on pecan and american ash, fraxinus ameri ...200312650352
leaf senescence and late-season net photosynthesis of sun and shade leaves of overstory sweetgum (liquidambar styraciflua) grown in elevated and ambient carbon dioxide concentrations.we examined the effects of elevated co2 concentration ([co2]) on leaf demography, late-season photosynthesis and leaf n resorption of overstory sweetgum (liquidambar styraciflua l.) trees in the duke forest free air co2 enrichment (face) experiment. sun and shade leaves were subdivided into early leaves (formed in the overwintering bud) and late leaves (formed during the growing season). overall, we found that leaf-level net photosynthetic rates were enhanced by atmospheric co2 enrichment throug ...200312533305
optical properties of intact leaves for estimating chlorophyll concentration.changes in leaf chlorophyll content can serve as relative indicators of plant vigor and environmental quality. this study identified reflectance, transmittance, and absorptance wavebands and band ratios within the 400- to 850-nm range for intact leaves that could be used to estimate extracted leaf chlorophyll per unit leaf area (areal concentration) with minimal error. leaf optical properties along with chlorophyll a, b, and a + b concentrations were measured for the planar-leaved sweetgum (liqu ...200212371158
coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms.a central question in lignin biosynthesis is how guaiacyl intermediates are hydroxylated and methylated to the syringyl monolignol in angiosperms. to address this question, we cloned cdnas encoding a cytochrome p450 monooxygenase (lsm88) and a caffeate o-methyltransferase (comt) from sweetgum (liquidambar styraciflua) xylem. mass spectrometry-based functional analysis of lsm88 in yeast identified it as coniferyl aldehyde 5-hydroxylase (cald5h). comt expressed in escherichia coli methylated 5-hyd ...199910430877
differential leaf resistance to insects of transgenic sweetgum (liquidambar styraciflua) expressing tobacco anionic peroxidase.leaves of transgenic sweetgum (liquidambar styraciflua) trees that expressed tobacco anionic peroxidase were compared with leaves of l. styraciflua trees that did not express the tobacco enzyme. leaves of the transgenic trees were generally more resistant to feeding by caterpillars and beetles than wild-type leaves. however, as for past studies with transgenic tobacco and tomato expressing the tobacco anionic peroxidase, the degree of relative resistance depended on the size of insect used and t ...19989711237
urbanization affects stream ecosystem function by altering hydrology, chemistry, and biotic richness.catchment urbanization can alter physical, chemical, and biological attributes of stream ecosystems. in particular, changes in land use may affect the dynamics of organic matter decomposition, a measure of ecosystem function. we examined leaf-litter decomposition in 18 tributaries of the st. johns river, florida, usa. land use in all 18 catchments ranged from 0% to 93% urban which translated to 0% to 66% total impervious area (tia). using a litter-bag technique, we measured mass loss, fungal bio ...200617069372
influence of bark ph on the occurrence and distribution of tree canopy myxomycete species.this study compares the occurrence and distribution of myxomycete species in the canopy of living trees and neighboring grapevines. corticolous myxomycetes of three temperate forests in southeastern usa were studied on six tree species (30 trees) and grapevines (30 vines) to determine distribution and occurrence of myxomycete species relating to geographic location, host species, and bark ph. the double-rope climbing technique was used to access the canopy and sample bark up to 16.5 m. bark samp ...200818592896
evaporation of intercepted precipitation from fruit litter of liquidambar styraciflua l. (sweetgum) in a clearing as a function of meteorological conditions.interception of precipitation by fruit litter is a poorly understood component of the hydrologic cycle in forested ecosystems. even less well understood is the effect of meteorological conditions on the evaporation of precipitation intercepted by forest litter. this study sought to examine the influence of meteorological conditions on the evaporation of intercepted precipitation by fruit litter from liquidambar styraciflua l. (sweetgum) by deriving and calibrating a regression model to estimate ...200415580361
the roles of seedling salt tolerance and resprouting in forest zonation on thewest coast of florida, usa.to determine whether the zonation of seven coastal tree species in north florida correlated with the relative abilities of their seedlings to tolerate soil salinity, we subjected seedlings of sabal palmetto, juniperus virginiana var. silicicola, quercus virginiana, celtis laevigata, ulmus spp., acer floridanum, and liquidambar styraciflua to a range of salinities (ôê+0, 2, 4, 8, 15, and 22 g synthetic sea salt/l; up to 63% full strength seawater salinity) in a 6-mo greenhouse experiment. pots wi ...199821680335
radiation-use efficiency and gas exchange responses to water and nutrient availability in irrigated and fertilized stands of sweetgum and sycamore.we investigated how water and nutrient availability affect radiation-use efficiency (epsilon) and assessed leaf gas exchange as a possible mechanism for shifts in epsilon. we measured aboveground net primary production (anpp) and annual photosynthetically active radiation (par) capture to calculate epsilon as well as leaf-level physiological variables (light-saturated net photosynthesis, asat; stomatal conductance, gs; leaf internal co2 concentration, ci; foliar nitrogen concentration, foliar [n ...200515574400
leaf respiratory acclimation to climate: comparisons among boreal and temperate tree species along a latitudinal transect.in common gardens along an ∼900 km latitudinal transect through wisconsin and illinois, u.s.a., tree species typical of boreal and temperate forests were compared with respect to the nature and magnitude of leaf respiratory acclimation to contrasting climates. the boreal representatives were trembling aspen (populus tremuloides michx.) and paper birch (betula papyrifera marsh.), while the temperate species were eastern cottonwood (populus deltoides bartr ex. marsh var. deltoides) and sweetgum (l ...201121990024
inhibitory effects of benzyl benzoate and its derivatives on angiotensin ii-induced hypertension.hypertension is a lifestyle-related disease which often leads to serious conditions such as heart disease and cerebral hemorrhage. angiotensin ii (ang ii) plays an important role in regulating cardiovascular homeostasis. consequently, antagonists that block the interaction of ang ii with its receptors are thought to be effective in the suppression of hypertension. in this study, we searched for plant compounds that had antagonist-like activity toward ang ii receptors. from among 435 plant sample ...200818672373
biology and management of insect pests in north american intensively managed hardwood forest systems.increasing demand for wood and wood products is putting stress on traditional forest production areas, leading to long-term economic and environmental concerns. intensively managed hardwood forest systems (imhfs), grown using conventional agricultural as well as forestry methods, can help alleviate potential problems in natural forest production areas. although imhfs can produce more biomass per hectare per year than natural forests, the ecologically simplified, monocultural systems may greatly ...200515355232
canopy conductance of pinus taeda, liquidambar styraciflua and quercus phellos under varying atmospheric and soil water conditions.sap flow, and atmospheric and soil water data were collected in closed-top chambers under conditions of high soil water potential for saplings of liquidambar styraciflua l., quercus phellos l. and pinus taeda l., three co-occurring species in the southeastern usa. responses of canopy stomatal conductance (g(t)) to water stress induced by high atmospheric water vapor demand or transpiration rate were evaluated at two temporal scales. on a diurnal scale, the ratio of canopy stomatal conductance to ...199812651370
long-term co2 enrichment of a forest ecosystem: implications for forest regeneration and succession.the composition and successional status of a forest affect carbon storage and net ecosystem productivity, yet it remains unclear whether elevated atmospheric carbon dioxide (co2) will impact rates and trajectories of forest succession. we examined how co2 enrichment (+200 microl co2/l air differential) affects forest succession through growth and survivorship of tree seedlings, as part of the duke forest free-air co2 enrichment (face) experiment in north carolina, usa. we planted 2352 seedlings ...200717555228
distribution, hosts, and morphological characteristics of tylenchulus palustris in florida and bermuda.studies on the geographical distribution and hosts of tylenchulus palustris were conducted over a 3-year period in florida and bermuda. tylenchulus palustris was found on aster elliottii and liquidambar styraciflua roots in swamps of northern and central florida. it was detected also on borrichia arborescens and b. frutescens roots in tidal marshes of northern florida and coastal rocklands of southern florida and bermuda. posterior bodies of t. palustris swollen females from bermuda did not diff ...199019287787
aldouronate utilization in paenibacillus sp. strain jdr-2: physiological and enzymatic evidence for coupling of extracellular depolymerization and intracellular metabolism.paenibacillus sp. strain jdr-2, an aggressively xylanolytic bacterium isolated from decaying sweet gum wood, secretes a multimodular glycohydrolase family gh10 endoxylanase (xyna1) anchored to the cell surface. the gene encoding xyna1 is part of a xylan utilization regulon that includes an aldouronate utilization gene cluster with genes encoding a gh67 alpha-glucuronidase (agua), a gh10 endoxylanase (xyna2), and a gh43 arabinofuranosidase/beta-xylosidase (xynb). here we show that this paenibacil ...200919395566
sweetgum (liquidambar styraciflua l.): extraction of shikimic acid coupled to dilute acid pretreatment.liquidambar styraciflua l., also known as sweetgum, is an understory hardwood species that has widespread distribution in the southeast usa, especially in pine plantations. in addition to being a possible biorefinery feedstock, sweetgum contains shikimic acid, which is a precursor for the drug tamiflu. sweetgum bark was extracted with 65 degrees c water and yielded 1.7 mg/g of shikimic acid, while sweetgum de-barked wood yielded 0.2 mg/g of shikimic acid. because shikimic acid can be extracted w ...201020506045
parasitic habits of trophotylenchulus floridensis (tylenchulidae) and its taxonomic relationship to tylenchulus semipenetrans and allied species.parasitism by trophotylenchulus floridensis raski, 1957 was studied on roots of sand pine (pinus clausa [chapm.] vasey). different life stages of the nematode were observed to be covered by dark, spherical, brittle, capsule-like structures which protruded from the root surface. the mature capsule enveloped a single sedentary female with a gelatinous matrix containing an average of 76 (44-117) eggs. the capsule was composed of a single layer of cells which appeared to be of plant origin. the ante ...198319295840
phytoremediation of chlorinated ethenes in seepline sediments: tree selection.phytoremediation of chlorinated ethene (ce)-contaminated water was investigated at the savannah river site in aiken, sc, usa. perchloroethylene (pce) and trichloroethylene (tce) are present where ce-contaminated groundwater currently outcrops in seepline soils. results of constructed and planted test cells, filled with soil from a noncontaminated seepline area and supplied with ce-contaminated groundwater (48 ppb) in the field for one season are presented. these test cells were planted with lobl ...200819260231
immunocytochemical characterization of tension wood: gelatinous fibers contain more than just cellulose.gelatinous fibers (g-fibers) are the active component of tension wood. g-fibers are unlike traditional fiber cells in that they possess a thick, nonlignified gelatinous layer (g-layer) internal to the normal secondary cell wall layers. for the past several decades, the g-layer has generally been presumed to be composed nearly entirely of crystalline cellulose, although several reports have appeared that disagreed with this hypothesis. in this report, immunocytochemical techniques were used to in ...200821632390
comparative infructescence morphology in altingia (altingiaceae) and discordance between morphological and molecular phylogenies.altingia (altingiaceae) is a tropical to subtropical asian genus of lowland trees for which 5-15 species have been recognized. morphological diversity, particularly of the mature infructescence, has been poorly known, especially for species with relatively localized and narrow distributions, and our understanding of altingia has lagged behind that of its close temperate relative liquidambar (sweet gum). in this contribution, mature infructescence structure, at the levels of anatomy, morphology, ...200721636478
leaf respiration at different canopy positions in sweetgum (liquidambar styraciflua) grown in ambient and elevated concentrations of carbon dioxide in the field.trees exposed to elevated co2 partial pressure ([co2]) generally show increased rates of photosynthesis and growth, but effects on leaf respiration are more variable. the causes of this variable response are unresolved. we grew 12-year-old sweetgum trees (liquidambar styraciflua l.) in a free-air co2 enrichment (face) facility in ambient [co2] (37/44 pa daytime/nighttime) and elevated [co2] (57/65 pa daytime/nighttime) in native soil at oak ridge national environmental research park. nighttime r ...200212414375
co2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest.* greater fine-root production under elevated [co2] may increase the input of carbon (c) and nitrogen (n) to the soil profile because fine root populations turn over quickly in forested ecosystems. * here, the effect of elevated [co)] was assessed on root biomass and n inputs at several soil depths by combining a long-term minirhizotron dataset with continuous, root-specific measurements of root mass and [n]. the experiment was conducted in a co(2)-enriched sweetgum (liquidambar styraciflua) pla ...200818537885
phylogeographical structure and temporal complexity in american sweetgum (liquidambar styraciflua; altingiaceae).eastern north american plant biogeography has traditionally focused on two primary issues: (i) the location of temperate pleistocene refugia and their proximity to the southern margin of the ice sheet during the last glacial maximum, and (ii) the origin of the temperate element of northern latin america. while numerous population genetic and phylogeographical studies have focused on the first issue, few (if any) have considered the second. we addressed these issues by surveying 117 individuals f ...200818662227
host compatibility of the cloud forest mistletoe psittacanthus schiedeanus (loranthaceae) in central veracruz, mexico.the consequences of the seed deposition of the parasitic mistletoe psittacanthus schiedeanus were evaluated in a 32-mo study. we conducted a field seed inoculation experiment to determine variation in seed adhesion, seed germination, seedling establishment, and plant survival to reproduction among five host species and to evaluate whether these post-dispersal processes explain mistletoe prevalence and specificity at the regional scale. seeds without an exocarp were inoculated onto branches of in ...200221669716
sweet tasting solutions for reduction of needle-related procedural pain in children aged one to 16 years.large numbers of studies have shown that oral sucrose or glucose, with or without non-nutritive sucking given prior to painful procedures result in a significant reduction in behavioral pain responses during or following painful procedures compared with placebo, no treatment or non-nutritive sucking alone, in newborns and infants up to 12 months of age. it is not known if these pain-reducing effects exist for older infants and children one year to 16 years of age.201121975781
variable conductivity and embolism in roots and branches of four contrasting tree species and their impacts on whole-plant hydraulic performance under future atmospheric co₂ concentration.anatomical and physiological acclimation to water stress of the tree hydraulic system involves trade-offs between maintenance of stomatal conductance and loss of hydraulic conductivity, with short-term impacts on photosynthesis and long-term consequences to survival and growth. here, we study the role of variations in root and branch maximum hydraulic specific conductivity (k(s-max)) under high and low soil moisture in determining whole-tree hydraulic conductance (k(tree)) and in mediating stoma ...201020566583
litterfall 15n abundance indicates declining soil nitrogen availability in a free-air co2 enrichment experiment.forest productivity increases in response to carbon dioxide (co2) enrichment of the atmosphere. however, in nitrogen-limited ecosystems, increased productivity may cause a decline in soil nitrogen (n) availability and induce a negative feedback on further enhancement of forest production. in a free-air co2 enrichment (face) experiment, the response of sweetgum (liquidambar styraciflua l.) productivity to elevated co2 concentrations [co2] has declined over time, but documenting an associated chan ...201121560683
comparative infructescence morphology in liquidambar (altingiaceae) and its evolutionary significance.the sweet gum genus liquidambar (altingiaceae) has two species in eastern asia, one in eastern north america, and one in western asia. mature infructescences are studied to provide anatomical, morphological, and micromorphological details, some of which are newly recognized. homology is suggested between extrafloral spinose processes of l. formosana and l. acalycina, braid-like ornamentation of l. styraciflua, and broad intercarpellate areas of l. orientalis. morphology, position, number, and th ...200521646145
genotoxic and cytotoxic effects of storax in vitro.the aim of this study is to investigate the effects of the storax balsam, which is a kind of sweet gum obtained from the liquidambar orientalis mill trees, on cell viability, cytotoxicity and genotoxicity in human lymphocyte in vitro. we studied the genotoxic effects of the extract of storax balsam (se) using sister chromatid exchange (sce) test system. also the cytotoxic and inhibitory effects on cell proliferation of se were evaluated using lactate dehydrogenase (ldh) assay and cell proliferat ...201122155886
[effects of phosphorus stress on the growth and nitrogen and phosphorus absorption of different formosan sweet gum provenances].aiming at the ecological value of formosan sweet gum (liquidambar formosana) as a pioneer species and the status of red soil phosphorus (p) deficiency, a sand culture experiment of split design was conducted to study the responses of three-leaf stage seedlings of seven formosan sweet gum provenances from yixing of jiangsu, jingxian of anhui, yongkang of zhejiang, nanchang of jiangxi, shaowu of fujian, yanping of fujian, and nandan of guangxi to four levels of p (p0, p1/2, p1, p2). with increasin ...200919565751
genetic engineering of enterobacter asburiae strain jdr-1 for efficient production of ethanol from hemicellulose hydrolysates.dilute acid pretreatment is an established method for hydrolyzing the methylglucuronoxylans of hemicellulose to release fermentable xylose. in addition to xylose, this process releases the aldouronate methylglucuronoxylose, which cannot be metabolized by current ethanologenic biocatalysts. enterobacter asburiae jdr-1, isolated from colonized wood, was found to efficiently ferment both methylglucuronoxylose and xylose in acid hydrolysates of sweet gum xylan, producing predominantly ethanol and ac ...200919617386
belowground fate of (15)n injected into sweetgum trees (liquidambar styraciflua) at the ornl face experiment.nitrogen (n) cycling can be an important constraint on forest ecosystem response to elevated atmospheric co(2). our objective was to trace the movement of (15)n, injected into tree sap, to labile and stable forms of soil organic matter derived partly from the turnover of tree roots under elevated (545 ppm) and ambient (394 ppm) atmospheric co(2) concentrations at the oak ridge national laboratory (ornl) face (free-air carbon dioxide enrichment) experiment. twenty-four sweetgum trees, divided equ ...200919705377
co2 enhancement of forest productivity constrained by limited nitrogen availability.stimulation of terrestrial plant production by rising co(2) concentration is projected to reduce the airborne fraction of anthropogenic co(2) emissions. coupled climate-carbon cycle models are sensitive to this negative feedback on atmospheric co(2), but model projections are uncertain because of the expectation that feedbacks through the nitrogen (n) cycle will reduce this so-called co(2) fertilization effect. we assessed whether n limitation caused a reduced stimulation of net primary producti ...201020974944
elevated co2 enhances leaf senescence during extreme drought in a temperate forest.in 2007, an extreme drought and acute heat wave impacted ecosystems across the southeastern usa, including a 19-year-old liquidambar styraciflua l. (sweetgum) tree plantation exposed to long-term elevated (e(co(2))) or ambient (a(co(2))) co(2) treatments. stem sap velocities were analyzed to assess plant response to potential interactions between co(2) and these weather extremes. canopy conductance and net carbon assimilation (a(net)) were modeled based on patterns of sap velocity to estimate in ...201121427157
[detecting leaf and twig temperature of some trees by using thermography].noninvasive detection of temperature with thermography from natural things has been used in many fields and it was attempted to detect the temperature for leaves and branches of trees in the present paper. leaf and twig temperatures were monitored during the increasing process of temperature under the direct sunshine heating. the difference of specific heat and latent heat from leaves and twigs caused by different water content and transpiration capacity were measured. not only the leaf temperat ...201021284152
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