| spiroplasmas: serological grouping of strains associated with plants and insects. | spiroplasma strains from plant and arthropod hosts, and from surfaces of flowers, were classified into three serological groups (designated i, ii, and iii) based on results from growth-inhibition tests. no significant cross reactions were observed among groups. the groupings were confirmed by ring-interface precipitin and microprecipitin tests, using membrane preparations as test antigens, and by organism-deformation tests. serogroup i contained three subgroups: subgroup a (spiroplasma citri str ... | 1979 | 93504 |
| spiroplasma associated with flowers of the tulip tree (liriodendron tulipifera l.). | spiroplasmas were isolated and cultivated from nonsurface-sterilized petals and bracts excised from flowers of liriodendron tulipifera l. (tulip tree) in anne arundel, charles, and prince george's counties in maryland, and east lyme county, connecticut. all isolates grew at 30 and at 37 degrees c. morphology of colonies on solid agar (1%) medium containing serum differed among isolates: some isolates formed highly diffuse, barely visible colonies; others formed distinct colonies with granular ce ... | 1978 | 688103 |
| two antimicrobial alkaloids from heartwood of liriodendron tulipifera l. | alcoholic extracts of the heartwood of liriodendron tulipifera have demonstrated antimicrobial activity against staphylococcus aureus, mycobacterium smegmatis, candida albicans, and aspergillus niger. the antimicrobial activity was associated only with the alkaloidal fraction. separation of the active alkaloidal fraction by chromatography led to the isolation and identification of dehydroglaucine and liriodenine as the active components. several other alkaloidal derivatives were prepared and tes ... | 1975 | 807704 |
| [liriodenine in tissue culture of liriodendron tulipifera l. ii. quantitative analysis and antifungal effect]. | | 1985 | 3913280 |
| dna homology among diverse spiroplasma strains representing several serological groups. | deoxyribonucleic acid (dna) homology among 10 strains of spiroplasma associated with plants and insects was assessed by analysis of dna-dna hybrids with single strand specific s1 nuclease. based on dna homology, the spiroplasmas could be divided into three genetically distinct groups (designated i, ii, and iii), corresponding to three separate serogroups described previously. dna sequence homology between the three groups was less than or equal to 5%. based on dna homology, group i could be divi ... | 1980 | 7214225 |
| [white wood allergy (liriodendron tulipifera, magnoliaceae (author's transl)]. | | 1980 | 7439036 |
| plant calreticulin is specifically and efficiently phosphorylated by protein kinase ck2. | calreticulin isolated from spinach leaves has been specifically phosphorylated in vitro by protein kinase ck2 while animal calreticulin from rabbit liver is not a substrate of this kinase under the same conditions. phosphoserine is the only phosphoamino acid detected. high affinity binding (km = 4.4 microm) and a nearly stoichiometric incorporation of phosphate was determined. partially purified spinach calreticulin is phosphorylated at the same site(s) by a copurifying protein kinase sharing bi ... | 1996 | 8629990 |
| visualization of the cytoskeleton within the secondary vascular system of hardwood species. | a single fixation technique has been devised to demonstrate localization of alpha-tubulin (for microtubules) and f-actin (for microfilaments) within the secondary vascular system of hardwood trees by indirect immunofluorescence microscopy using butyl-methylmethacrylate-embedded material. application of this technique to problems of cytomorphogenesis during secondary growth and its versatility are demonstrated with the hardwood species aesculus hippocastanum l., salix viminalis l., s. burjatica n ... | 1997 | 9316269 |
| characterization and heterologous expression of laccase cdnas from xylem tissues of yellow-poplar (liriodendron tulipifera). | four closely related cdna clones encoding laccase isoenzymes from xylem tissues of yellow-poplar (ltlacc2.1-4) were identified and sequenced. the inferred yellow-poplar laccase gene products were highly related to one another (79-91% at the amino acid level) and showed significant similarity to other blue copper oxidases, especially with respect to the copper-binding domains. the encoded proteins had n-terminal signal sequences and 17-19 potential n-linked glycosylation sites. the mature protein ... | 1999 | 10394942 |
| foliar temperature-respiration response functions for broad-leaved tree species in the southern appalachians. | we measured leaf respiration in 18 eastern deciduous forest tree species to determine if there were differences in temperature-respiration response functions among species or among canopy positions. leaf respiration rates were measured in situ and on detached branches for acer pensylvanicum l., a. rubrum l., betula spp. (b. alleghaniensis britt. and b. lenta l.), carya glabra (mill.) sweet, cornus florida l., fraxinus spp. (primarily f. americana l.), liriodendron tulipifera l., magnolia fraseri ... | 1999 | 10562404 |
| simulating the response of mature yellow poplar and loblolly pine trees to shifts in peak ozone periods during the growing season using the tregro model. | multiple tregro simulations were conducted with meteorological data files containing different growing season peak ozone (o(3)) episodes at o(3) exposures of 1.0 and 2.0 x ambient o(3) to assess the relationship between o(3) response and the phenology of mature yellow poplar (liriodendron tulipifera l.) and loblolly pine (pinus taeda l.) trees. regardless of o(3) exposure and peak o(3) episode occurrence, a peak o(3) episode in august caused the greatest reduction in carbon (c) gain in yellow po ... | 1997 | 14759902 |
| growth and photosynthetic responses of four virginia piedmont tree species to shade. | to determine the effects of shade on biomass, carbon allocation patterns and photosynthetic response, seedlings of loblolly pine (pinus taeda l.), white pine (pinus strobus l.), red maple (acer rubrum l.), and yellow-poplar (liriodendron tulipifera l.) were grown without shade or in shade treatments providing a 79 or 89% reduction of full sunlight for two growing seasons. the shade treatments resulted in less total biomass for all species, with loblolly pine showing the greatest shade-induced gr ... | 1996 | 14871684 |
| estimates of net photosynthetic parameters for twelve tree species in mature forests of the southern appalachians. | leaf gas exchange, temperature, and incident radiation were measured in situ for 20 mature trees of 12 deciduous species spanning a range of heights from 7.9 to 30.1 m and growing in the southern appalachian mountains. air temperature, water vapor pressure, total radiation, photosynthetically active radiation, and carbon dioxide concentration were also measured. estimated mean, light-saturated net assimilation rates ( micro mol m(-2) s(-1)) were: quercus coccinea muenchh. (10.3), q. prinus l. (9 ... | 1996 | 14871725 |
| variation in seedling hydraulic architecture as a function of species and environment. | northern red oak (quercus rubra l.) and yellow-poplar (liriodendron tulipifera l.) were grown for two years in full sunlight (unshaded) or 20% of full sunlight (shaded) under either well-watered or drought conditions. there was a close association between evaporative flux (in situ) and leaf-specific conductivity (lsc) in stem segments of both species. shaded, drought-stressed seedlings of both species had significantly reduced leaf area, evaporative flux, volume flow rate in xylem, flow velocity ... | 1993 | 14969933 |
| carbon budgets of temperate forest ecosystems. | a summary of carbon-budget data from 30 forest stands is presented together with information on both above- and belowground ecosystem components. only 10 of the stands had complete biomass data, 21 had complete productivity data and six had heterotrophic, or autotrophic respiration data, or both. the most comprehensive stand-level data have been collected for pinus spp., pseudotsuga menziesii, abies amabilis and liriodendron tulipifera. only incomplete carbon budgets are available for most ecosy ... | 1991 | 14972857 |
| ferroxidase activity in a laccase-like multicopper oxidase from liriodendron tulipifera. | ferroxidase activity was detected in a laccase-like multicopper oxidase (lmco) produced in transgenic tobacco cells expressing an lmco cdna (ltlacc2.2) cloned from yellow-poplar (liriodendron tulipifera). this marks the first report of ferroxidase activity associated with a plant laccase and suggests that some members of this plant enzyme family may have physiological functions based on activities other than their more widely recognized phenoloxidase activity. recent work with lmcos from bacteri ... | 2004 | 15061081 |
| does predation contribute to tree diversity? | seed and seedling predation may differentially affect competitively superior tree species to increase the relative recruitment success of poor competitors and contribute to the coexistence of tree species. we examined the effect of seed and seedling predation on the seedling recruitment of three tree species, acer rubrum (red maple), liriodendron tulipifera (yellow poplar), and quercus rubra (northern red oak), over three years by manipulating seed and seedling exposure to predators under contra ... | 2005 | 15719246 |
| how are leaves plumbed inside a branch? differences in leaf-to-leaf hydraulic sectoriality among six temperate tree species. | the transport of water, sugar, and nutrients in trees is restricted to specific vascular pathways, and thus organs may be relatively isolated from one another (i.e. sectored). strongly sectored leaf-to-leaf pathways have been shown for the transport of sugar and signal molecules within a shoot, but not previously for water transport. the hydraulic sectoriality of leaf-to-leaf pathways was determined for current year shoots of six temperate deciduous tree species (three ring-porous: castanea dent ... | 2005 | 15983007 |
| potential tree species for use in the restoration of unsanitary landfills. | given that they represent the most economical option for disposing of refuse, waste landfills are widespread in urban areas. however, landfills generate air and water pollution and require restoration for landscape development. a number of unsanitary waste landfills have caused severe environmental problems in developing countries. this study aimed to investigate the colonization status of different tree species on waste landfills to assess their potential for restoring unsanitary landfills in s ... | 2005 | 16132448 |
| variations in organic acid exudation and aluminum resistance among arbuscular mycorrhizal species colonizing liriodendron tulipifera. | aluminum (al) in acidic soils is toxic to plants, affecting growth, water uptake and nutrient assimilation. aluminum resistance in some plant species and genotypes has been ascribed to organic acid exudation from roots and arbuscular mycorrhizal (am) fungal symbiosis. we investigated variation among several am species in altering al resistance of liriodendron tulipifera l. and evaluated am influence on organic acid production as a potential al resistance mechanism. growth, nutritional responses ... | 2007 | 17472937 |
| 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 ... | 2007 | 17555228 |
| effect of scoparone on neurite outgrowth in pc12 cells. | the neurite outgrowth-promoting effects of scoparone isolated from the stem bark of liriodendron tulipifera were investigated in pc12 cells. at a concentration of 200 microm, scoparone markedly induced neurite outgrowth from pc12 cells. scoparone at 200 microm also enhanced the outgrowth of neurites from cells in the presence of nerve growth factor (ngf, 2 ng/ml). the levels of intracellular cyclic amp and concentration of ca2+ were also increased by 200 microm scoparone. in addition, scoparone ... | 2008 | 18547723 |
| 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 ... | 2008 | 18592896 |
| biodegradation and saccharification of wood chips of pinus strobus and liriodendron tulipifera by white rot fungi. | degradation and glucose production from wood chips of white pine (pinus strobus) and tulip tree (liriodendron tulipifera) by several white rot fungi were investigated. the highest weight losses from 4 g of wood chips of p. strobus and l. tulipifera by the fungal degradation on yeast extractmalt extract-glucose agar medium were 38% of irpex lacteus and 93.7% of trametes versicolor mrp 1 after 90 days, respectively. when 4 g of wood chips of p. strobus and l. tulipifera biodegraded for 30 days wer ... | 2008 | 19047827 |
| nematodes parasitic on forest trees: iii. reproduction on selected hardwoods. | the host-parasite relationships of 13 species of plant parasitic nematodes and five species of hardwoods native to the southeastern united states were tested on greenhouse-grown tree seedlings for 6-10 months. criteria for parasitism were completion o f life cycle and population increase of nematodes. belonolaimus longicaudatus, helicotylenchus dihystera, scutellonema brachyurum and tylenchorhynchus claytoni parasitized and reproduced on three or more of the species tested. hoplolaimus galeatus ... | 1971 | 19322363 |
| hardwood tree survival in heavy ground cover on reclaimed land in west virginia: mowing and ripping effects. | current west virginia coal mining regulations emphasize reforestation as a preferred postmining land use on surface mined areas. some mined sites reclaimed to pasture are being converted to forests. in the spring of 2001, we compared the establishment and growth of five hardwood tree species on a reclaimed west virginaia surface mine with compacted soils and a heavy grass groundcover. we planted 1-yr-old seedlings of five species (black cherry [prunus serotina ehrh.], red oak [quercus rubra l.], ... | 2009 | 19465715 |
| seasonal variation and bioactivity in the leaf oil of liriodendron tulipifera growing in huntsville, alabama. | the seasonal variation in the chemical composition of the leaf essential oil of liriodendron tulipifera has been analyzed by gc-ms. two individual trees were sampled five times during the course of the growing season. twenty components were identified in the leaf oils, which were dominated by sesquiterpene hydrocarbons, principally germacrene d and beta-elemene, in the early part of the season (42-44% and 18-23%, respectively,) but monoterpene hydrocarbons, largely (z)-beta-ocimene, dominated th ... | 2009 | 19634333 |
| survival and growth of hardwoods in brown versus gray sandstone on a surface mine in west virginia. | surface mining in west virginia removes the eastern deciduous forest and reclaiming the mined land to a productive forest must consider soil depth, soil physical and chemical properties, soil compaction, ground cover competition, and tree species selection. our objective was to evaluate tree survival and growth in weathered brown sandstone and in unweathered gray sandstone. brown and gray sandstone are often substituted when insufficient native topsoil is available for replacement. three 2.8-ha ... | 2009 | 19643747 |
| rapid characterization of biomass using near infrared spectroscopy coupled with multivariate data analysis: part 1. yellow-poplar (liriodendron tulipifera l.). | this paper is the first of a two series papers on the use of near infrared (nir) coupled with multivariate data analysis (mvda) as a process analytical technology (pat) tool for the rapid characterization of physical and chemical properties of two common west virginian hardwood species, northern red oak (quercus rubra) and yellow-poplar (liriodendron tulipifera l.). these two wood species are potential feed stock for the bio-refinery industry. in part 1, we report our results on yellow-poplar. t ... | 2010 | 20163955 |
| hardwood seedling growth on different mine spoil types with and without topsoil amendment. | the goal of many owners of reclaimed mined land in the appalachian region is to restore the diverse native hardwood forest for environmental, economic, and cultural reasons. however, native hardwoods often grow poorly on mined sites because they are planted in unsuitable spoils devoid of native topsoil. in a greenhouse experiment, we examined the suitability of four growth media available for use on many mined sites in the central appalachians-forest topsoil (ft), weathered sandstone (ws), unwea ... | 2010 | 20176821 |
| reconstructing holocene fire history in a southern appalachian forest using soil charcoal. | lacking long-term dendrochronological and lake sediment data, little is known regarding the history of fire in southern appalachian forests through the holocene. here we used 82 radiocarbon ages for soil charcoal collected from local depositional sites along a topographic gradient from mixed hardwood (liriodendron tulipifera and quercus spp.) to oak-pine (quercus prinus and pinus rigida) forest to provide a coarse-grained picture of changes in fire frequency within a 10-ha area during the holoce ... | 2010 | 20426326 |
| contrasting the morphology, anatomy and fungal colonization of new pioneer and fibrous roots. | • not all roots born as first-order branches are the same and this has important consequences for overall function. we hypothesized that, compared with fibrous roots, pioneer roots are built to live longer at the expense of absorptive capacity. • we tested this hypothesis by investigating pioneer and fibrous roots in their first 14 d of life in the arbuscular mycorrhizal tree species: acer negundo, acer saccharum, juglans nigra, liriodendron tulipifera and populus tremuloides. root observations ... | 2011 | 21210817 |
| hydraulic patterns and safety margins, from stem to stomata, in three eastern u.s. tree species. | adequate water transport is necessary to prevent stomatal closure and allow for photosynthesis. dysfunction in the water transport pathway can result in stomatal closure, and can be deleterious to overall plant health and survival. although much is known about small branch hydraulics, little is known about the coordination of leaf and stem hydraulic function. additionally, the daily variations in leaf hydraulic conductance (k(leaf)), stomatal conductance and water potential (+¿(l)) have only bee ... | 2011 | 21724585 |
| def- and glo-like proteins may have lost most of their interaction partners during angiosperm evolution. | deficiens (def)- and globosa (glo)-like proteins constitute two sister clades of floral homeotic transcription factors that were already present in the most recent common ancestor (mrca) of extant angiosperms. together they specify the identity of petals and stamens in flowering plants. in core eudicots, def- and glo-like proteins are functional in the cell only as heterodimers with each other. there is evidence that this obligate heterodimerization contributed to the canalization of the flower ... | 2014 | 24902716 |
| effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay ambrosia beetle and granulate ambrosia beetle (coleoptera: curculionidae: scolytinae). | the redbay ambrosia beetle, xyleborus glabratus eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family lauraceae. this study assessed the relative attractiveness and suitability of cut bolts of several tree species to x. glabratus. in 2009, female x. glabratus were equally attracted to traps baited with swampbay (persea palustris (rafinesque) sargent) and camphortree (cinnamomum camphora (l.) j. presl), which were more attr ... | 2012 | 22606816 |
| foraging strategies in trees of different root morphology: the role of root lifespan. | resource exploitation of patches is influenced not simply by the rate of root production in the patches but also by the lifespan of the roots inhabiting the patches. we examined the effect of sustained localized nitrogen (n) fertilization on root lifespan in four tree species that varied widely in root morphology and presumed foraging strategy. the study was conducted in a 12-year-old common garden in central pennsylvania using a combination of data from minirhizotron and root in-growth cores. t ... | 2013 | 24128849 |
| insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps. | insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. we conducted a three-year experiment (2012-2014) deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in maryland. during this ... | 2017 | 28344904 |
| foliar damage beyond species distributions is partly explained by distance dependent interactions with natural enemies. | plant distributions are expected to shift in response to climate change, and range expansion dynamics will be shaped by the performance of individuals at the colonizing front. these plants will encounter new biotic communities beyond their range edges, and the net outcome of these encounters could profoundly affect colonization success. however, little is known about how biotic interactions vary across range edges and this has hindered efforts to predict changes in species distributions in respo ... | 2016 | 27859086 |
| drought enhances symbiotic dinitrogen fixation and competitive ability of a temperate forest tree. | general circulation models project more intense and frequent droughts over the next century, but many questions remain about how terrestrial ecosystems will respond. of particular importance, is to understand how drought will alter the species composition of regenerating temperate forests wherein symbiotic dinitrogen (n2)-fixing plants play a critical role. in experimental mesocosms we manipulated soil moisture to study the effect of drought on the physiology, growth and competitive interactions ... | 2014 | 24337710 |
| future species composition will affect forest water use after loss of eastern hemlock from southern appalachian forests. | infestation of eastern hemlock (tsuga canadensis (l.) carr.) with hemlock woolly adelgid (hwa, adelges tsugae) has caused widespread mortality of this key canopy species throughout much of the southern appalachian mountains in the past decade. because eastern hemlock is heavily concentrated in riparian habitats, maintains a dense canopy, and has an evergreen leaf habit, its loss is expected to have a major impact on forest processes, including transpiration (e(t)). our goal was to estimate chang ... | 2013 | 23865229 |
| nonadditive effects of leaf litter species diversity on breakdown dynamics in a detritus-based stream. | since species loss is predicted to be nonrandom, it is important to understand the manner in which those species that we anticipate losing interact with other species to affect ecosystem function. we tested whether litter species diversity, measured as richness and composition, affects breakdown dynamics in a detritus-based stream. using full-factorial analyses of single- and mixed-species leaf packs (15 possible combinations of four dominant litter species; red maple [acer rubrum], tulip poplar ... | 2007 | 17536403 |
| a six-year study of sapling and large-tree growth and mortality responses to natural and induced variability in precipitation and throughfall. | global climatic change may cause changes in regional precipitation that have important implications for forest growth in the southern united states. in 1993, a stand-level experiment was initiated on walker branch watershed, tennessee, to study the sensitivity of forest saplings and large trees to changes in soil water content. soil water content was manipulated by gravity-driven transfer of precipitation throughfall from a dry treatment plot (-33%) to a wet treatment plot (+33%). a control plot ... | 2001 | 11282574 |
| photosynthetic sunfleck utilization potential of understory saplings growing under elevated co2 in face. | few studies have evaluated elevated co2 responses of trees in variable light despite its prevalence in forest understories and its potential importance for sapling survival. we studied two shade-tolerant species (acer rubrum, cornus florida) and two shade-intolerant species (liquidambar styraciflua, liriodendron tulipifera) growing in the understory of a pinus taeda plantation under ambient and ambient+200 ppm co2 in a free air carbon enrichment (face) experiment. photosynthetic and stomatal res ... | 2000 | 28308370 |
| leaf litter processing and exoenzyme production on leaves in streams of different ph. | we examined microbial colonization, exoenzyme activity, and processing of leaves of yellow poplar (liriodendron tulipifera), red maple (acer rubrum), and white oak (quercus alba) in three streams on the allegheny plateau of west virginia, united states. leaf packs were placed in streams that varied in their underlying bedrock geology, and therefore in their sensitivity to the high level of acidic precipitation that occurs in this region. the mean ph of the streams was 4.3 in the south fork of re ... | 1995 | 28306889 |
| allelochemicals in foliage of unfavored tree hosts of the gypsy moth,lymantria dispar l. : 1. alkaloids and other components ofliriodendron tulipifera l. (magnoliaceae),acer rubrum l. (aceraceae), andcornus florida l. (cornaceae). | early theories on plant chemical defense against herbivory emphasized that apparent and unapparent plants were primarily defended by different types of compounds. more and more evidence suggests that both quantitative and qualitative defenses are found in apparent plants and that they can play a defensive role against herbivores. a survey of the literature on the gypsy moth suggests not only that there is a large variety of qualitative compounds, as well as the expected quantitative ones, but th ... | 1990 | 24263840 |
| seasonal patterns of leaf water relations in four co-occurring forest tree species: parameters from pressure-volume curves. | leaf water relationships were studied in four widespread forest tree species (ilex opaca ait., cornus florida l., acer rubrum l., and liriodendron tulipifera l.). the individuals studied all occurred on the same site and were selected to represent a range of growth forms and water relationships in some of the principal tree species of the region. the water relations of the species were analyzed using the concept of the water potential-water content relationship. the pressure-volume method was us ... | 1980 | 28310040 |
| comparative photosynthesis of three gap phase successional tree species. | photosynthesis was measured in situ on trees growing in an open, gap-like site and under a closed canopy. photosynthetic responses also were monitored on trees grown in the laboratory under either a high or low light regime or on those trees transferred from a low to a high light regime. all three species studied, liriodendron tulipifera, acer rubrum and cornus florida, were able to acclimate to a high light environment as evidenced by their higher photosynthetic rates. this acclimation was achi ... | 1980 | 28309559 |
| components of water potential estimated from xylem pressure measurements in five tree species. | pressure volume curves were measured with a pressure bomb in leaves collected in the field from ilex opaca, acer rubrum, liquidambar styraciflua, liriodendron tulipifera and cornus florida. water potential components were calculated from the curves. the species differed in the relationships measured. in all species the trends from summer to fall were toward lower (more negative) osmotic potentials, lower matric potentials more rapid loss of turgor with increasing leaf water deficit, and the occu ... | 1977 | 28309017 |
| allelopathic effects of juglone on germination and growth of several herbaceous and woody species. | laboratory experiments were conducted to determine juglone sensitivity of 16 species (trifolium incarnatum, coronilla varia, vicia villosa, lespedeza stipulacea, l. cuneata, acer ginnala, caragana arbor-escens, elaegnus angustifolia, e. umbellata, lonicera maackii, quercus alba, fraxinus americana, liriodendron tulipifera, alnus glutinosa, pinus strobus, andp. sylvestris) being considered for mixed plantings withjugions nigra (black walnut). all species were sensitive to juglone, but seed germin ... | 1983 | 24407348 |
| development of transgenic yellow poplar for mercury phytoremediation. | we examined the ability of yellow poplar (liriodendron tulipifera) tissue cultures and plantlets to express modified mercuric reductase (mera) gene constructs. mercury-resistant bacteria express mera to convert highly toxic, ionic mercury, hg(ii), to much less toxic, elemental mercury, hg(o). expression of mera in transgenic plants might provide an ecologically compatible approach for the remediation of mercury pollution. because the alteration of the bacterial mera gene sequence is necessary fo ... | 1998 | 9788347 |
| calcium and aluminum cycling in a temperate broadleaved deciduous forest of the eastern usa: relative impacts of tree species, canopy state, and flux type. | ca/al molar ratios are commonly used to assess the extent of aluminum stress in forests. this is among the first studies to quantify ca/al molar ratios for stemflow. ca/al molar ratios in bulk precipitation, throughfall, stemflow, litter leachate, near-trunk soil solution, and soil water were quantified for a deciduous forest in northeastern md, usa. data were collected over a 3-year period. the ca/al molar ratios in this study were above the threshold for aluminum stress (<1). fagus grandifolia ... | 2015 | 26100445 |
| meteorological influences on stemflow generation across diameter size classes of two morphologically distinct deciduous species. | many tree species have been shown to funnel substantial rainfall to their stem base as stemflow flux, given a favorable stand structure and storm conditions. as stemflow is a spatially concentrated flux, prior studies have shown its impact on ecohydrological and biogeochemical processes can be significant. less work has been performed examining stemflow variability from meteorological conditions compared to canopy structural traits. as such, this study performs multiple regressions: (1) to exami ... | 2014 | 24615637 |
| leaf litter species evenness influences nonadditive breakdown in a headwater stream. | species loss directly affects the magnitude and stability of various ecosystem processes, and species composition can drive this phenomenon. much of the evidence that species loss affects ecosystem processes comes from experiments where species richness was manipulated while holding abundance/biomass of individual species constant. given that species rarely coexist in equal proportions, neglecting evenness might under/overestimate the role of important species combinations. we examined leaf litt ... | 2009 | 19569379 |
| a community classification system for forest evaluation: development, validation, and extrapolation. | a community classification system integrating vegetation and landforms was developed for the 8,054-ha cheatham wildlife management area (cwma), located on the western highland rim of tennessee, usa, to obtain information on which to base multiresource land management decisions. a subjective procedure (synthesis tables) and several objective techniques (factor analysis, cluster analysis, and canonical discrimination) were used to evaluate importance values of overstory and midstory species, cover ... | 1996 | 24198012 |