| metabolism of atrazine by spartina alterniflora. 1. chloroform-soluble metabolites. | | 1977 | 881505 |
| carbon metabolism in model microbial systems from a temperate salt marsh. | the metabolism of a saltwater leachate of 14c-labeled spartina alterniflora was examined in laboratory systems using mixed, salt marsh microbial communities and, by addition of appropriate antibiotics, communities with bacteria or eukaryotes inhibited. label uptake was more rapid in the systems with bacteria alone and with the mixed microbial community than with fungi alone. mineralization of the added label was more extensive in the mixed and bacterial systems, whereas the fungi appear more eff ... | 1976 | 938043 |
| effects of cucl2 on the germination response of two populations of the saltmarsh cordgrass, spartina alterniflora. | | 1990 | 2344482 |
| stable carbon isotope analysis of nucleic acids to trace sources of dissolved substrates used by estuarine bacteria. | the natural abundance of stable carbon isotopes measured in bacterial nucleic acids extracted from estuarine bacterial concentrates was used to trace sources of organic matter for bacteria in aquatic environments. the stable carbon isotope ratios of pseudomonas aeruginosa and nucleic acids extracted from cultures resembled those of the carbon source on which bacteria were grown. the carbon isotope discrimination between the substrate and total cell carbon from bacterial cultures averaged 2.3% +/ ... | 1990 | 2389930 |
| tight coupling of root-associated nitrogen fixation and plant photosynthesis in the salt marsh grass spartina alterniflora and carbon dioxide enhancement of nitrogenase activity. | the coupling of root-associated nitrogen fixation and plant photosynthesis was examined in the salt marsh grass spartina alterniflora. in both field experiments and hydroponic assay chambers, nitrogen fixation associated with the roots was rapidly enhanced by stimulating plant photosynthesis. a kinetic analysis of acetylene reduction activity (ara) showed that a five-to sixfold stimulation occurred within 10 to 60 min after the plant leaves were exposed to light or increased co2 concentrations ( ... | 1986 | 3089156 |
| relationship between nitrogen-fixing sulfate reducers and fermenters in salt marsh sediments and roots of spartina alterniflora. | a combination of inhibitors and carbon substrates was used to determine the relative contribution of sulfate-reducing bacteria (srb) and fermenting bacteria to nitrogen fixation in a salt marsh sediment and on the roots of spartina alterniflora. because a lag period precedes acetylene-reducing activity (ara) in amended sediments, an extensive analysis was done to be sure that this activity was due to the activation of dormant cells, not simply to cell proliferation. since ara was not affected by ... | 1988 | 3178210 |
| degradation of polysaccharides and lignin by ruminal bacteria and fungi. | bermudagrass (cynodon dactylon) leaf blades and whole cordgrass (spartina alterniflora) fiber were evaluated for degradation of cell walls by microbial groups in ruminal fluid. the groups were selected by the addition of antibiotics to the inoculum as follows: (i) whole ruminal fluid (wrf), no antibiotics; (ii) cycloheximide (c) to inhibit fungi, thus showing potential bacterial activity; (iii) streptomycin and penicillin (s,p) to inhibit fiber-degrading bacteria, showing potential fungal activi ... | 1988 | 3389808 |
| evidence for nh4+ switch-off regulation of nitrogenase activity by bacteria in salt marsh sediments and roots of the grass spartina alterniflora. | the regulatory effect of nh4+ on nitrogen fixation in a spartina alterniflora salt marsh was examined. acetylene reduction activity (ara) measured in situ was only partially inhibited by nh4+ in both the light and dark after 2 h. in vitro analysis of bulk sediment divided into sediment particles, live and dead roots, and rhizomes showed that microbes associated with sediment and dead roots have a great potential for anaerobic c2h2 reduction, but only if amended with a carbon source such as manno ... | 1986 | 3456738 |
| distribution of larval tabanidae (diptera) in a spartina alterniflora salt marsh. | | 1974 | 4828349 |
| investigation of selective uptake of polychlorinated biphenyls by spartina alterniflora loisel. | | 1981 | 6796156 |
| an improved gas chromatographic method for measuring glucosamine and muramic acid concentrations. | a method of simultaneously measuring glucosamine and muramic acid concentrations in marsh grass litter was developed. spartina alterniflora samples were preextracted with acetone to remove lipids containing amino sugars and then hydrolyzed in 6 n hcl (100 degrees c, 4.5 h). amino sugars in the hydrolysates were isolated by ion-exchange chromatography, which gave good recoveries (greater than 90%) and reproducibility (cv less than 5%). isolated amino sugars were converted to o-methyloxime acetate ... | 1983 | 6846818 |
| isolation of a nitrogen-fixing campylobacter species from the roots of spartina alterniflora loisel. | a microaerophilic nitrogen-fixing bacterium was isolated from surface-sterilized roots of spartina alterniflora loisel growing in a nova scotian salt marsh. it is a small curved rod and is motile with a single polar flagellum. metabolism is respiratory. organic and amino acids, but not carbohydrates, serve as carbon and energy sources. the guanine + cytosine content of its deoxyribonucleic acid is 32.1 +/- 1.0 mol%. based upon morphological and biochemical characteristics this organism is assign ... | 1980 | 6936066 |
| accumulation of polychlorinated terphenyls in aquatic biota of an estuarine creek. | aroclor 5432, a mixture of polychlorinated terphenyls (pct), was detected in several biological compartments including saltmarsh cordgrass (spartina alterniflora), american oysters (crassostrea virginica), red-jointed fiddler crabs (uca minax), wharf crabs (sesarma reticulatum), and mummichogs (fundulus heteroclitus) collected from tabbs creek. this tidal creek is located in the southern chesapeake bay region and contains sediments with high concentrations of pct. samples were collected at four ... | 1993 | 7507821 |
| [effects of bio-mineral food additive on health]. | spartina alterniflora, one kind of bio-mineral food additive and special nutrient liquid, rich in bioactive materials, was extracted from a marsh plant grown in beach. it can enhance immune function of animals and human bodies, increase the tolerance to hypoxia in rats, prolong life span of fruit flies, and increase activity of human serum superoxide dismutase. | 1995 | 7600885 |
| differential metabolism of dimethylsulfoniopropionate and acrylate in saline and brackish intertidal sediments | in anoxic spartina alterniflora-dominated sediments along a naturally occuring salinity gradient (the cooper river estuary, south carolina, u.s.a.), dimethylsulfoniopropionate (dmsp) was metabolized to dimethyl sulfide (dms) and acrylate by sediment microbes. the rate of dmsp degradation and acrylate mineralization by sediment microbes was similar at all sites along this 25-km transect. however, sediments amended with acrylate (or dmsp) showed significantly higher rates of n2 fixation (measured ... | 1996 | 8661536 |
| enhanced biodegradation of diesel fuel through the addition of particulate organic carbon and inorganic nutrients in coastal marine waters. | diesel fuel pollution in coastal waters, resulting from recreational boating and commercial shipping operations, is common and can adversely affect marine biota. the purpose of this study was to examine the effect of additions of particulate organic carbon (poc) in the form of naturally-occurring marsh grass (spartina alterniflora), inorganic nutrients (nitrogen and phosphorus), inert particles, and dissolved organic carbon (doc) on diesel fuel biodegradation and to attempt to formulate an effec ... | 1996 | 8782394 |
| lignocellulolysis by ascomycetes (fungi) of a saltmarsh grass (smooth cordgrass). | lignocellulose (lc) makes up greater than 70% of the mature shoots of the prodigiously photosynthetically productive saltmarsh grass spartina alterniflora. naturally decaying shoots of this cordgrass were examined by transmission electron microscopy (after high-pressure freezing and freeze-substitution) as a means of directly detecting lysis of the lc-rich tissues. portions of the cordgrass were selected that contained ascomata (sexual reproductive structures) of only one of each of four species ... | 1996 | 8820663 |
| seasonal changes in the relative abundance of uncultivated sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of spartina alterniflora. | phylogenetic diversity and community composition of sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of spartina alterniflora were investigated. uncultivated desulfobacteriaceae family-related phylotypes were studied by selectively amplifying 16s rrna gene fragments from dna extracted from salt marsh rhizosphere samples. two novel phylotypes were retrieved from rhizosphere samples, with a01 having 89.1% sequence similarity with desulfococcus multivorans and 4d19 having 9 ... | 1997 | 9327553 |
| dimethylsulfoniopropionate biosynthesis in spartina alterniflora1. evidence that s-methylmethionine and dimethylsulfoniopropylamine are intermediates. | the osmoprotectant 3-dimethylsulfoniopropionate (dmsp) occurs in gramineae and compositae, but its synthesis has been studied only in the latter. the dmsp synthesis pathway was therefore investigated in the salt marsh grass spartina alterniflora loisel. leaf tissue metabolized supplied [35s]methionine (met) to s-methyl-l-met (smm), 3-dimethylsulfoniopropylamine (dmsp-amine), and dmsp. the 35s-labeling kinetics of smm and dmsp-amine indicated that they were intermediates and, consistent with this ... | 1998 | 9576797 |
| physiological diversity of the rhizosphere diazotroph assemblages of selected salt marsh grasses. | rhizosphere diazotroph assemblages of salt marsh grasses are thought to be influenced by host plant species and by a number of porewater geochemical parameters. several geochemical variables can adversely affect plant productivity and spatial distributions, resulting in strong zonation of plant species and growth forms. this geochemically induced stress may also influence the species compositions and distributions of rhizosphere diazotroph assemblages, but little is currently known about these o ... | 1998 | 9797277 |
| phylogenetic and physiological diversity of sulphate-reducing bacteria isolated from a salt marsh sediment. | the phylogenetic and physiological diversity of sulphate-reducing bacteria inhabiting a salt marsh rhizosphere were investigated. sulphate-reducing bacteria were isolated from a salt marsh rhizosphere using enrichment cultures with electron donors thought to be prevalent in the rhizosphere of spartina alterniflora. the relationship between phylogeny and nutritional characteristics of 10 strains was investigated. none of the isolates had 16s rrna sequences identical to other delta subclass sulpha ... | 1998 | 9924824 |
| evolution of a new ecotype of spartina alterniflora (poaceae) in san francisco bay, california, usa. | we report the discovery and spread of a dwarf ecotype of spartina alterniflora in san francisco bay. relative to typical s. alterniflora, this dwarf ecotype has one-fifth the tiller height (~21 cm), tenfold the tiller density (~4000 tillers/m), and is restricted to growth in the upper intertidal zone. chromosome counts of the dwarfs are identical to typical smooth cordgrass (2n = 62), and smooth cordgrass-specific random amplified dna markers confirm the species identity of the dwarf. field-coll ... | 1999 | 10205074 |
| molecular phylogenetic and biogeochemical studies of sulfate-reducing bacteria in the rhizosphere of spartina alterniflora | the population composition and biogeochemistry of sulfate-reducing bacteria (srb) in the rhizosphere of the marsh grass spartina alterniflora was investigated over two growing seasons by molecular probing, enumerations of culturable srb, and measurements of so42- reduction rates and geochemical parameters. so42- reduction was rapid in marsh sediments with rates up to 3.5 &mgr;mol ml-1 day-1. rates increased greatly when plant growth began in april and decreased again when plants flowered in late ... | 1999 | 10224021 |
| effects of drainage and soil organic content on growth of spartina alterniflora (poaceae) in an artificial salt marsh mesocosm. | an artificial salt marsh mesocosm was constructed using 680-l polypropylene tanks to determine the effect of soil drainage depth and organic content on growth and rhizome proliferation of the salt marsh smooth cordgrass spartina alterniflora. soil drainage depth had no effect on accumulation of aerial or subsurface plant tissue, but tanks that had 2.5% soil organic content supported enhanced aerial tissue and rhizome growth compared to tanks that contained sand alone. we propose a mathematical m ... | 1999 | 10330073 |
| salt marsh diking and restoration: biogeochemical implications of altered wetland hydrology. | / in salt marshes, most biomass plus large reserves of biologically important n, p, fe, and s are sequestered below ground under saline, waterlogged, and anaerobic conditions. thus, hydrologic alterations such as diking and ditch drainage that reduce salinity and increase peat aeration can cause radical changes in the composition of salt marsh soils.experimental short-term desalination and drainage of salt marsh cores in greenhouse microcosms caused spartina production to increase after one grow ... | 1999 | 10341067 |
| spatial and temporal assessment of diazotroph assemblage composition in vegetated salt marsh sediments using denaturing gradient gel electrophoresis analysis. | > abstract diazotroph assemblage compositions were assessed in rhizosphere sediments from the tall and short form spartina alterniflora growth zones over an annual cycle. sediment cores were collected for dna extraction and nitrogenase (acetylene reduction) activity assays, and porewater samples were analyzed for several chemical parameters in march, june, september, and december 1997. these data were collected to determine if within- or between-zone differences in the diazotroph assemblage comp ... | 1999 | 10441708 |
| extent and degree of hybridization between exotic (spartina alterniflora) and native (s. foliosa) cordgrass (poaceae) in california, usa determined by random amplified polymorphic dna (rapds). | spartina alterniflora, smooth cordgrass, native to the eastern usa, was introduced into south san francisco bay approximately 25 years ago. it has spread by purposeful introduction of rooted plants and dispersal of seeds on the tides. previous work suggested that s. alterniflora was competitively superior to the native california cordgrass, s. foliosa, and that the two species hybridized. the present study determined the spread of s. alterniflora and s. foliosa x alterniflora hybrids in californ ... | 1999 | 10447858 |
| ferric iron reduction by bacteria associated with the roots of freshwater and marine macrophytes. | in vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of >100 micromol g (dry weight)(-1) day(-1) for three freshwater macrophytes and rates between 15 and 83 micromol (dry weight)(-1) day(-1) for two marine species. the rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). sodium molybdate added at final concentrations of 0.2 to 20 mm did not inhibit iron reduction by roots o ... | 1999 | 10508065 |
| autumnal biomass and potential productivity of salt marsh fungi from 29 degrees to 43 degrees north latitude along the united states atlantic coast. | it has been established that substantial amounts of fungal mass accumulate in standing decaying smooth cordgrass (spartina alterniflora) marshes in the southeastern united states (e.g., in standing decaying leaf blades with a total fungal organic mass that accounts for about 20% of the decay system organic mass), but it has been hypothesized that in marshes farther north this is not true. we obtained samples of autumnal standing decaying smooth cordgrass from sites in florida to maine over a 3-y ... | 2000 | 10618221 |
| fungal biomass in saltmarsh grass blades at two contaminated sites. | ascomycetous fungi are the principal drivers of the decomposition of shoots of smooth cordgrass (spartina alterniflora). shoots of smooth cordgrass move into the saltmarsh food web via the decomposition system. therefore, influences on saltmarsh ascomycetes by pollutants of saltmarshes could have far-reaching impacts. earlier examination of impacts of severe contamination of a georgia saltmarsh by mercury and polychlorinated biphenyls (pcbs) revealed little or no influence of the toxicants on li ... | 2000 | 10667923 |
| phylogenetic characterization of marine bacterium strain 2-40, a degrader of complex polysaccharides. | the marine bacterium strain 2-40 was isolated from the salt marsh cord grass, spartina alterniflora, in the chesapeake bay watershed, va, usa. it is gram-negative, requires sea salts and is a strict aerobe. it degrades numerous complex polysaccharides and synthesizes eumelanin. by 16s rdna analysis, the isolate was shown to be a member of the gamma-subclass of the proteobacteria, related to microbulbifer hydrolyticus and to a cellulolytic nitrogen-fixing bacterium. | 2000 | 10758894 |
| stability in natural bacterial communities: i. nutrient addition effects on rhizosphere diazotroph assemblage composition. | the ability of rhizosphere diazotrophs to remain competitive during increased nitrogen availability in situ was tested in a salt marsh grass stand. nitrogen (16.3 g m(-2)) or nitrogen (16.3 g m(-2)) and phosphorus (18.0 g m(-2)) were added to plots of short form spartina alterniflora for either 2 weeks or 8 weeks. the diazotroph assemblage composition was monitored via the polymerase chain reaction using nifh specific primers followed by denaturing gradient gel electrophoresis (dgge) analysis. d ... | 2000 | 10790515 |
| stability in natural bacterial communities: ii. plant resource allocation effects on rhizosphere diazotroph assemblage composition. | plant rhizospheres are dynamic environments in which microbes compete for resources, particularly plant-derived organic carbon/energy sources. altering plant productivity changes the availability of carbon/energy resources to rhizosphere microbiota. this limitation is expected to intensify competition for the remaining carbon supply and could cause the loss of poor competitors from the assemblage. we clipped or shaded plots of the salt marsh cord grass, spartina alterniflora, to shift plant carb ... | 2000 | 10790516 |
| microdiversity of culturable diazotrophs from the rhizoplanes of the salt marsh grasses spartina alterniflora and juncus roemerianus. | salt marshes dominated by spartina alterniflora (smooth cordgrass) are among the most productive ecosystems known, despite nitrogen limitation. rhizoplane/rhizosphere diazotrophy (nitrogen fixation) serves as a significant source of combined nitrogen in these systems. several recent studies have demonstrated remarkable physiological and phylogenetic macro- and microdiversity within this important functional group of organisms. however, the ecological significance of this diversity is presently u ... | 2000 | 10833225 |
| biochemical evidence for two novel enzymes in the biosynthesis of 3-dimethylsulfoniopropionate in spartina alterniflora. | 3-dimethylsulfoniopropionate (dmsp) is an osmoprotectant accumulated by the cordgrass spartina alterniflora and other salt-tolerant plants. previous in vivo isotope tracer and metabolic modeling studies demonstrated that s. alterniflora synthesizes dmsp via the route s-methyl-met --> 3-dimethylsulfoniopropylamine (dmsp-amine) --> 3-dimethylsulfoniopropionaldehyde --> dmsp and indicated that the first reaction requires a far higher substrate concentration than the second to attain one-half-maxima ... | 2000 | 10889264 |
| molecular analysis of diazotroph diversity in the rhizosphere of the smooth cordgrass, spartina alterniflora. | n(2) fixation by diazotrophic bacteria associated with the roots of the smooth cordgrass, spartina alterniflora, is an important source of new nitrogen in many salt marsh ecosystems. however, the diversity and phylogenetic affiliations of these rhizosphere diazotrophs are unknown. denaturing gradient gel electrophoresis (dgge) of pcr-amplified nifh sequence segments was used in previous studies to examine the stability and dynamics of the spartina rhizosphere diazotroph assemblages in the north ... | 2000 | 10966395 |
| persistence of selected spartina alterniflora rhizoplane diazotrophs exposed to natural and manipulated environmental variability. | rhizoplane-rhizosphere nitrogen-fixing microorganisms (diazotrophs) are thought to provide a major source of biologically available nitrogen in salt marshes dominated by spartina alterniflora. compositional and functional stability has been demonstrated for this important functional group; however, the quantitative responses of specific diazotroph populations to environmental variability have not been assessed. changes in the relative abundances of selected rhizoplane diazotrophs in response to ... | 2000 | 11055903 |
| identification and characterization of humic substances-degrading bacterial isolates from an estuarine environment. | bacterial isolates were obtained from enrichment cultures containing humic substances extracted from estuarine water using an xad-8 resin. eighteen isolates were chosen for phylogenetic and physiological characterization based on numerical importance in serial dilutions of the enrichment culture and unique colony morphology. partial sequences of the 16s rrna genes indicated that six of the isolates were associated with the alpha subclass of proteobacteria, three with the gamma-proteobacteria, an ... | 2000 | 11102687 |
| the effect of mercury and pcbs on organisms from lower trophic levels of a georgia salt marsh. | we examined several indicators of salt marsh function, focusing on primary producers, microbes, and grass shrimp, at a superfund site (lcp) contaminated with mercury and polychlorinated biphenyls (pcbs) and a reference site (cross-river) in georgia. primary production of spartina alterniflora was assessed by measuring peroxidase activity (pod), glutathione concentration (tgsh), photosynthesis (a(net)), and transpiration (e). microbial populations were assessed by measuring living-fungal standing ... | 2001 | 11116336 |
| the relevance of rooted vascular plants as indicators of estuarine sediment quality. | toxicity assessments and numerical quality assessment guidelines for estuarine sediments are rarely based on information for aquatic plants. the effect of this lack of information on contaminated sediment toxicity evaluations is largely unknown. for this reason, the toxicities of whole sediments collected from 15 sites in three urbanized florida bayou-estuaries were determined for the benthic invertebrates mysidopsis bahia and ampelisca abdita and the plants scirpus robustus pursh (saltmarsh bul ... | 2001 | 11116338 |
| phylogenetic analysis of culturable dimethyl sulfide-producing bacteria from a spartina-dominated salt marsh and estuarine water. | dimethylsulfoniopropionate (dmsp), an abundant osmoprotectant found in marine algae and salt marsh cordgrass, can be metabolized to dimethyl sulfide (dms) and acrylate by microbes having the enzyme dmsp lyase. a suite of dms-producing bacteria isolated from a salt marsh and adjacent estuarine water on dmsp agar plates differed markedly from the pelagic strains currently in culture. while many of the salt marsh and estuarine isolates produced dms and methanethiol from methionine and dimethyl sulf ... | 2001 | 11229912 |
| recovery and analysis of formyltetrahydrofolate synthetase gene sequences from natural populations of acetogenic bacteria. | primers for pcr amplification of partial (1,102 of 1,680 bp) formyltetrahydrofolate synthetase (fthfs) gene sequences were developed and tested. partial fthfs sequences were successfully amplified from dna from pure cultures of known acetogens, from other fthfs-producing organisms, from the roots of the smooth cordgrass, spartina alterniflora, and from fresh horse manure. the amplimers recovered were cloned, their nucleotide sequences were determined, and their translated amino acid sequences we ... | 2001 | 11229939 |
| long-term fate of glyphosate associated with repeated rodeo applications to control smooth cordgrass (spartina alterniflora) in willapa bay, washington. | cordgrasses (spartina sp.) are exotic, invasive species that threaten to degrade the intertidal zones of estuaries along the west coast of north america. integrated pest management (ipm) strategies primarily focus on the use of aerial and ground applications of rodeo in conjunction with mowing, but ipm treatments over multiple years usually are necessary to control spartina. although information exists regarding the short-term fate and effects to marine biota of a single rodeo application to con ... | 2001 | 11243319 |
| habitat-related predation on juvenile wild-caught and hatchery-reared red drum sciaenops ocellatus (linnaeus). | we examined the patterns of habitat-specific mortality for newly settled red drum (sciaenops ocellatus) using an experimental mesocosm approach. experiments were designed to analyze prey vulnerability and fish rearing-type (wild-caught or hatchery-reared) in estuarine habitats of varying structural complexity including marsh (spartina alterniflora loisel), oyster reef (crassostrea virginica gmelin), seagrass (halodule wrightii aschers), and nonvegetated sand bottom. we used two different predato ... | 2001 | 11358569 |
| wetland plant seedlings as indicators of near-coastal sediment quality: interspecific variation. | the toxicities of whole sediments collected from an urbanized florida bayou-estuary were determined for the epibenthic mysid, mysidopsis bahia, and the infaunal amphipod, ampelisca abdita. in addition, the phytotoxicities of the same sediments were evaluated using rooted macrophytes, scirpus robustus pursh and spartina alterniflora loisel. the results of the 24 bioassays conducted for 7-28 days, were compared for interspecific differences. toxicity to the benthic invertebrate species was predict ... | 2000 | 11460746 |
| molecular investigations in populations of spartina anglica c.e. hubbard (poaceae) invading coastal brittany (france). | spartina anglica is a classical example of recent alloploid speciation. it arose during the end of the nineteenth century in england by hybridization between the indigenous spartina maritima and the introduced east-american spartina alterniflora. duplication of the hybrid genome (spartina x townsendii) gave rise to a vigorous allopolyploid involved in natural and artificial invasions on different continents. spartina anglica was first recorded in france in 1906, and since then, it has spread all ... | 2001 | 11472537 |
| recovery and phylogenetic analysis of nifh sequences from diazotrophic bacteria associated with dead aboveground biomass of spartina alterniflora. | dna was extracted from dry standing dead spartina alterniflora stalks as well as dry spartina wrack from the north inlet (south carolina) and sapelo island (georgia) salt marshes. partial nifh sequences were pcr amplified, the products were separated by denaturing gradient gel electrophoresis (dgge), and the prominent dgge bands were sequenced. most sequences (109 of 121) clustered with those from alpha-proteobacteria, and 4 were very similar (>99%) to that of azospirillum brasilense. seven sequ ... | 2001 | 11679360 |
| lead uptake, distribution, and effects in two dominant salt marsh macrophytes, spartina alterniflora (cordgrass) and phragmites australis (common reed). | we examined biomass accumulation, tissue concentrations of lead (pb), and net uptake of pb in phragmites australis (common reed) and spartina alterniflora (salt cord grass) grown under greenhouse conditions in sediment of different pb concentrations. sediment and newly emerged ramets of each plant species were collected in april 1999 from tuckerton, nj, a relatively clean salt marsh. one-gallon pots were filled with either control sediment (29 microg g(-1) pb) or pb-added sediment (68 microg g(- ... | 2001 | 11693635 |
| diversity of the ring-cleaving dioxygenase gene pcah in a salt marsh bacterial community. | degradation of lignin-related aromatic compounds is an important ecological process in the highly productive salt marshes of the southeastern united states, yet little is known about the mediating organisms or their catabolic pathways. here we report the diversity of a gene encoding a key ring-cleaving enzyme of the beta-ketoadipate pathway, pcah, amplified from bacterial communities associated with decaying spartina alterniflora, the salt marsh grass that dominates these coastal systems, as wel ... | 2001 | 11722937 |
| rapid shoreward encroachment of salt marsh cordgrass in response to accelerated sea-level rise. | the distribution of new england salt marsh communities is intrinsically linked to the magnitude, frequency, and duration of tidal inundation. cordgrass (spartina alterniflora) exclusively inhabits the frequently flooded lower elevations, whereas a mosaic of marsh hay (spartina patens), spike grass (distichlis spicata), and black rush (juncus gerardi) typically dominate higher elevations. monitoring plant zonal boundaries in two new england salt marshes revealed that low-marsh cordgrass rapidly m ... | 2001 | 11724926 |
| differentiation of plasmids in marine diazotroph assemblages determined by randomly amplified polymorphic dna analysis. | nitrogen fixation by diazotrophic bacteria is a significant source of new nitrogen in salt marsh ecosystems. recent studies have characterized the physiological and phylogenetic diversity of oxygen-utilizing diazotrophs isolated from the rhizoplanes of spatially separated intertidal macrophyte habitats. however, there is a paucity of information regarding the traits encoded by and the diversity of plasmids occurring in this key ecological functional group. five-hundred and twenty-one isolates cu ... | 2002 | 11782510 |
| molecular phylogeny of hybridizing species from the genus spartina schreb. (poaceae). | interspecific hybridization events have been reported in the genus spartina schreb. (poaceae), involving the east american species spartina alterniflora, and including either introgression (e.g., with the western american spartina foliosa) or allopolyploid speciation (e.g., with the euro-african spartina maritima). molecular phylogenetic analysis of the genus has been undertaken in order to understand phylogenetic relationships and genetic divergence among these hybridizing species. twelve spart ... | 2002 | 11820850 |
| salt marsh recovery and oil spill remediation after in-situ burning: effects of water depth and burn duration. | effects of water depth, burn duration, and diesel fuel concentration on the relationship between recovery of marsh vegetation, soil temperature, and oil remediation during in-situ burning of oiled mesocosms were investigated. the water depth over the soil surface during in-situ burning was a major factor controlling recovery of the salt marsh grass, spartina alterniflora. ten centimeters of water overlying the soil surface was sufficient to protect the marsh soil from burn impacts with soil temp ... | 2002 | 11878369 |
| effects of substrate salinity on early seedling survival and growth of scirpus robustus pursh and spartina alterniflora loisel. | rooted aquatic plants are being used increasingly to test the toxicity of sediments. however, effects of naturally occurring substrate constituents on most potential test species are not well understood even though their effects could affect the test results. the objective of this study was to determine the effect of substrate salinity (nacl) on early seedling survival and growth of the emergent macrophytes, scirpus robustus pursh and spartina alterniflora loisel. results of four 21- and 28-day ... | 2002 | 11895013 |
| recommended design for more accurate duplication of natural conditions in salt marsh creation. | construction of 653 ha of salt marsh habitat from dredged material near the aransas national wildlife refuge, texas, has been proposed, with the goal of increasing the area of habitat available to endangered whooping cranes ( grus americana). we assessed prototype created wetlands, and their similarity to natural reference sites, in terms of topography, vegetation, and hydrology. the created sites were steeply sloped relative to natural sites and were dominated by monotypic stands of spartina al ... | 2002 | 11992173 |
| physiological diversity of rhizoplane diazotrophs of the saltmeadow cordgrass, spartina patens: implications for host specific ecotypes. | diazotrophic bacteria are important contributors to salt marsh productivity, but the biotic and abiotic factors that influence their distributions and function and the extent of their diversity cannot be understood in the absence of physiological information. here we examine the physiological diversity and distribution patterns of diazotrophic bacteria associated with the rhizoplane of the saltmeadow cordgrass, spartina patens, in comparison with diazotrophs from other intertidal grasses (tall a ... | 2001 | 12024271 |
| analysis of internal transcribed spacer (its) regions of rrna genes in fungal communities in a southeastern u.s. salt marsh. | the ascomycete community colonizing decaying spartina alterniflora blades in a southeastern u.s. salt marsh was characterized by analysis of internal transcribed spacer (its) regions of fungal rrna genes. its sequences were amplified with ascomycete-specific primers from dna extracted from s. alterniflora blades at two stages of decay (early and late) and were identified based on sequence analysis of a companion ascomycete culture collection. the s. alterniflora its libraries were dominated by c ... | 2002 | 12037611 |
| fate of tributyltin in a created tidal wetland. | the ability of spartina alterniflora to degrade tributyltin (tbt) in contaminated dredge spoils was investigated in a created wetland at little creek naval amphibious base in norfolk, virginia, usa. concentrations of tbt up to 250 ng/g did not inhibit s. alterniflora growth over a 16-month period. disappearance rates of tbt in vegetated and unvegetated treatments were similar, with half-lives of 300 to 330 d. disappearance rates were not constant, but they were correlated to temperature changes ... | 2002 | 12069300 |
| imidacloprid residues in willapa bay (washington state) water and sediment following application for control of burrowing shrimp. | pesticides have been used in the willapa bay estuary in western washington state to control the exotic invasive plant species spartina alterniflora (cordgrass) and the native species of burrowing shrimp (callianassa sp.; upogebia sp.) that affect oyster production. carbaryl, the only registered insecticide for control of burrowing shrimp, has not been extensively studied in the willapa bay. however, carbaryl use has been severely restricted, and alternatives likely to have less severe environmen ... | 2002 | 12105979 |
| retrotransposons and genomic stability in populations of the young allopolyploid species spartina anglica c.e. hubbard (poaceae). | spartina x townsendii arose during the end of the 19th century in england by hybridization between the indigenous spartina maritima and the introduced spartina alterniflora, native to the eastern seaboard of north america. duplication of the hybrid genome gave rise to spartina anglica, a vigorous allopolyploid involved in natural and artificial invasions on several continents. this system allows investigation of the early evolutionary changes that accompany stabilization of new allopolyploid spe ... | 2002 | 12140233 |
| the dose-response relationship between no. 2 fuel oil and the growth of the salt marsh grass, spartina alterniflora. | the effect of no. 2 fuel oil on the biomass production of the salt marsh plant, spartina alterniflora, was studied in a greenhouse dose-response experiment. s. alterniflora were transplanted into soil with 10 dosage levels of no. 2 fuel oil ranging from 0 to 456 mg g(-1) dry soil. three months after transplantation, values for plant biomass, stem density, and shoot height decreased significantly with increasing fuel oil level in a dose-response fashion. evapo-transpiration rates were correlated ... | 2002 | 12405214 |
| release into the environment of metals by two vascular salt marsh plants. | metals in contaminated salt marshes are mainly locked in the anaerobic layer of sediments, where they are tightly bound as sulfides and organic complexes. vascular plants survive in saturated soils in part by pumping o2 into their root zones, changing their microenvironment to an oxic one. this, along with chelating exudates, mobilizes metals, allowing uptake by the roots. we compared the common reed phragmites australis and cordgrass spartina alterniflora in lab and field studies for ways in wh ... | 2002 | 12408582 |
| the impact of ozone on a salt marsh cordgrass (spartina alterniflora). | spartina alterniflora plants were collected from salt marshes within new jersey, south carolina, and georgia usa and shipped to the pennsylvania state university. new plants were grown from rhizomes in six open-top field chambers. three chambers received charcoal-filtered air, and three received charcoal-filtered air plus 80 ppb ozone, 8 h/day for 65 days. flower, leaf, and shoot number per plant were recorded weekly. photosynthetic rates were measured in week 5, and foliar injury was assessed d ... | 2002 | 12442793 |
| comparison of benthic invertebrate assemblages at spartina alterniflora marshes reestablished after an oil spill and existing marshes in the arthur kill (ny/nj). | in january 1990, an oil spill damaged salt marshes along the banks of the arthur kill (new york and new jersey, usa). in the years following the spill, spartina alterniflora seedlings were planted at a number of the oil damaged sites and successfully reestablished at these sites. in 1996, the national marine fisheries service began a study to compare the benthic invertebrate assemblages at the reestablished s. alterniflora marshes to those at nearby existing marshes in the arthur kill. oligochae ... | 2002 | 12474971 |
| formyltetrahydrofolate synthetase sequences from salt marsh plant roots reveal a diversity of acetogenic bacteria and other bacterial functional groups. | sixty-two partial formyltetrahydrofolate synthetase (fthfs) structural gene sequences were recovered from roots of salt marsh plants, including spartina alterniflora, salicornia virginica, and juncus roemerianus. only s. alterniflora roots yielded sequences grouping with fthfs sequences from known acetogens. most other fthfs or fthfs-like sequences grouped with those from sulfate-reducing bacteria. several sequences that grouped with sphingomonas paucimobilis ligh were also recovered. | 2003 | 12514064 |
| diversity of ascomycete laccase gene sequences in a southeastern us salt marsh. | the diversity of ascomycete laccase sequences was surveyed in a southeastern us salt marsh using a degenerate primer set designed around copper binding sites conserved in fungal laccases. this gene was targeted for diversity analysis because of its potential function in lignin degradation in the salt marsh ecosystem and because few studies have assessed functional gene diversity in natural fungal communities. laccase sequences were amplified from genomic dna extracted from 24 isolates (represent ... | 2003 | 12632211 |
| seasonal shift from bottom-up to top-down impact in phytophagous insect populations. | although many studies now examine how multiple factors influence the dynamics of herbivore populations, few studies explicitly attempt to document where and when each is important and how they vary and interact. in fact, how temporal variation in top-down (natural enemies) and bottom-up (host plant resources) factors affect herbivore dynamics has been suggested as a particularly important yet poorly understood feature of terrestrial food webs. in this study we examined how temporal changes in pr ... | 2003 | 12647120 |
| nitrogen fixation and nitrogen limitation of primary production along a natural marsh chronosequence. | nitrogen (n) limitation of primary production is common in temperate salt marshes, even though conservative n recycling can fulfill a large proportion of plant n demand. in nutrient poor young marshes, n limitation may be more severe and new n sources, such as n fixation, more important for plant growth. we measured n fixation and the response of salt marsh primary producers (spartina alterniflora and benthic microalgae) to n fertilization in one mature (>150 year) and two young (7 and 15 year) ... | 2003 | 12750992 |
| is the invasion of the common reed, phragmites australis, into tidal marshes of the eastern us an ecological disaster? | studies of effects of the invasive brackish marsh plant phragmites australis (common reed) on estuarine biota are reviewed. with few exceptions, most field studies indicate that these p. australis-dominated marshes have diverse and abundant benthic biota, and are utilized by nekton, comparable to spartina alterniflora marshes. however, larval mummichogs, fundulus heteroclitus, appear to be reduced in p. australis marshes compared with s. alterniflora marshes. small epifauna living on plant stems ... | 2003 | 12837299 |
| selenium removal and mass balance in a constructed flow-through wetland system. | a field study on the removal of se from agricultural subsurface drainage was conducted from may 1997 to february 2001 in the tulare lake drainage district (tldd) of san joaquin valley, california. a flow-through wetland system was constructed consisting of ten 15- x 76-m unlined cells that were continuously flooded and planted with either a monotype or combination of plants, including sturdy bulrush [schoenoplectus robustus (pursh) m.t. strong], baltic rush (juncus balticus willd.), smooth cordg ... | 2003 | 12931913 |
| sulfur stable isotopes separate producers in marine food-web analysis. | ecological applications of stable isotope analysis rely on different producers having distinct isotopic ratios to trace energy and nutrient transfer to consumers. carbon (c) and nitrogen (n) are the usual elements analysed. we tested the hypothesis that producers unable to be separated using c and n would be separated by sulphur (s), by reviewing estuarine and marine food web studies using all three elements (total of 836 pairwise comparisons between producers). s had a wider range of values acr ... | 2004 | 14593525 |
| dynamics of bacterial and fungal communities on decaying salt marsh grass. | both bacteria and fungi play critical roles in decomposition processes in many natural environments, yet only rarely have they been studied as an integrated microbial community. here we describe the bacterial and fungal assemblages associated with two decomposition stages of spartina alterniflora detritus in a productive southeastern u.s. salt marsh. 16s rrna genes and 18s-to-28s internal transcribed spacer (its) regions were used to target the bacterial and ascomycete fungal communities, respec ... | 2003 | 14602628 |
| concentrations of glyphosate and ampa in sediment following operational applications of rodeo to control smooth cordgrass in willapa bay, washington, usa. | | 2003 | 14705651 |
| assessment of a delta15n isotopic method to indicate anthropogenic eutrophication in aquatic ecosystems. | increased anthropogenic delivery of nutrients to water bodies, both freshwater and estuarine, has caused detrimental changes in habitat, food web structure, and nutrient cycling. nitrogen-stable isotopes may be suitable indicators of such increased nutrient delivery. in this study, we looked at the differences in response of macrophyte delta15n values to anthropogenic n across different taxonomic groups and geographic regions to test a stable isotopic method for detecting anthropogenic impacts. ... | 2004 | 14964366 |
| metal uptake, transport and release by wetland plants: implications for phytoremediation and restoration. | marshes have been proposed as sites for phytoremediation of metals. the fate of metals within plant tissues is a critical issue for effectiveness of this process. in this paper we review studies that investigate the effects of plants on metals in wetlands. while most of these marsh plant species are similar in metal uptake patterns and in concentrating metals primarily in roots, some species retain more of their metal burden in below ground structures than other species, which redistribute a gre ... | 2004 | 15051245 |
| evaluation of alternative oil spill cleanup techniques in a spartina alterniflora salt marsh. | three oil spill situations which cause long-term impact were simulated in 1 m(2) salt marsh plots to evaluate the effectiveness of alternative cleanup techniques at removing oil and reducing damage to spartina alterniflora. cleanup techniques, implemented 18-24 h after oiling, were not effective at removing oil after sediment penetration. when oil remained on the sediment surface, flushing techniques were most effective at removal, reducing levels of added oil by 73% to 83%. the addition of disp ... | 1988 | 15092503 |
| dimethylsulphoniopropionate (dmsp) and related compounds in higher plants. | dimethylsulphoniopropionate (dmsp) is produced in high concentrations in many marine algae, but in higher plants only in a few salt marsh grasses of the genus spartina, in sugar canes (saccharum spp.), and in the pacific strand plant wollastonia biflora (l.) dc. the high concentrations found in higher plants (up to 250 micromol g(-1) dry weight) suggest an important role, but though many functions have been suggested (including methylating agent, detoxification of excess sulphur, salt tolerance, ... | 2004 | 15181109 |
| pollen limitation causes an allee effect in a wind-pollinated invasive grass (spartina alterniflora). | it is usually assumed that pollen availability does not limit reproduction in wind-pollinated plants. little evidence either supporting or contradicting this assumption exists, despite the importance of seed production to population persistence and growth. we investigated the role of pollen limitation in an invasive estuarine grass (spartina alterniflora), with a manipulative pollen supplementation and exclusion experiment in areas of high population density and at the low-density leading edge o ... | 2004 | 15317944 |
| [emergy analysis on an added loop in spartina alterniflora ecological engineering]. | based on the principle of multi-grade utilization of resources to get ecological, economic and social benefits of ecological engineering, this paper designed an added loop, following the spartina alterniflora ecological engineering (saee). all the added loop design included saee, and the capsule was named saeec. in the added loop design, the biological mineral liquid (bml) was made into antihyperlipidemia capsules, of which, the total flavonoids added up to 9.58 mg x g(-1). emergy analysis metho ... | 2004 | 15334968 |
| metal dynamics of plant litter of spartina alterniflora and phragmites australis in metal-contaminated salt marshes. part 1: patterns of decomposition and metal uptake. | to investigate the decay rate and metal uptake in litter from two species of wetland plants, leaves and stems of senescent spartina alterniflora and phragmites australis (p) were obtained from the hackensack meadowlands (nj, usa) in october 1998, and their initial metal contents were determined. two types of s. alterniflora were obtained, one set from a natural site (ns) and one from a restored site (rs). leaves and stems were placed in separate litterbags, and samples of each type were reciproc ... | 2004 | 15376538 |
| cumulative impacts of dock shading on spartina alterniflora in south carolina estuaries. | salt marshes dominated by spartina alterniflora and the associated networks of tidal creeks that drain them are characteristic geographical features of southeastern estuaries, important nursery habitat areas, and preferred sites for residential development. as the size of the coastal population increases, so has the number of requests for dock permits. with each new request for a dock permit, public concerns about the cumulative environmental impacts of dock proliferation on the coastal environm ... | 2004 | 15503391 |
| quantification of ammonia-oxidizing bacteria and factors controlling nitrification in salt marsh sediments. | to elucidate the geomicrobiological factors controlling nitrification in salt marsh sediments, a comprehensive approach involving sediment geochemistry, process rate measurements, and quantification of the genetic potential for nitrification was applied to three contrasting salt marsh habitats: areas colonized by the tall (ts) or short (ss) form of spartina alterniflora and unvegetated creek banks (cbs). nitrification and denitrification potential rates were strongly correlated with one another ... | 2005 | 15640193 |
| genetic and epigenetic consequences of recent hybridization and polyploidy in spartina (poaceae). | to study the consequences of hybridization and genome duplication on polyploid genome evolution and adaptation, we used independently formed hybrids (spartina x townsendii and spartina x neyrautii) that originated from natural crosses between spartina alterniflora, an american introduced species, and the european native spartina maritima. the hybrid from england, s. x townsendii, gave rise to the invasive allopolyploid, salt-marsh species, spartina anglica. recent studies indicated that allopoly ... | 2005 | 15773943 |
| in situ burning of oil in coastal marshes. 1. vegetation recovery and soil temperature as a function of water depth, oil type, and marsh type. | in-situ burning of oiled wetlands potentially provides a cleanup technique that is generally consistent with present wetland management procedures. the effects of water depth (+10, +2, and -2 cm), oil type (crude and diesel), and oil penetration of sediment before the burn on the relationship between vegetation recovery and soil temperature for three coastal marsh types were investigated. the water depth over the soil surface during in-situ burning was a key factor controlling marsh plant recove ... | 2005 | 15819246 |
| genetic modification of wetland grasses for phytoremediation. | wetland grasses and grass-like monocots are very important natural remediators of pollutants. their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. tissue culture is prerequisite for genetic manipulation, and methods are reported here for in vitro culture and micropropagation of a number of wetland plants of various ecological requirements such as salt marsh, brackish water, riverbanks, and various zones of lak ... | 2005 | 15948597 |
| molecular characterization of sulfate-reducing bacteria in a new england salt marsh. | sulfate reduction, mediated by sulfate-reducing bacteria (srb), is the dominant remineralization pathway in sediments of new england salt marshes. high sulfate reduction rates are associated with the rhizosphere of spartina alterniflora when plants elongate aboveground. the growth process concurrently produces significant amounts of new rhizome material belowground and the plants leak dissolved organic compounds. this study investigated the diversity of srb in a salt marsh over an annual growth ... | 2005 | 16011754 |
| field investigation on the toxicity of alaska north slope crude oil (ansc) and dispersed ansc crude to gulf killifish, eastern oyster and white shrimp. | a field investigation was conducted on a louisiana spartina alterniflora shoreline to evaluate the toxic effects of crude oil (alaska north slope crude oil, ansc) and dispersed oil (ansc + dispersant corexit 9,500) on three aquatic species indigenous to the gulf of mexico: fundulus grandis (gulf killifish), crassostrea virginica (eastern oyster), and litopenaeus setiferus (white shrimp). results indicated that total hydrocarbons concentration value in oiled treatments decreased rapidly in 3h and ... | 2006 | 16098561 |
| uptake of polycyclic aromatic hydrocarbons (pahs) in salt marsh plants spartina alterniflora grown in contaminated sediments. | polycyclic aromatic hydrocarbon (pah) concentrations were measured in spartina alterniflora plants grown in pots of contaminated sediment, plants grown in native sediment at a marsh contaminated with up to 900 microg/g total pahs, and from plants grown in uncontaminated control sediment. the roots and leaves of the plants were separated, cleaned, and analyzed for pahs. pah compounds were detected at up to 43 microg/g dry weight in the root tissue of plants grown in pots of contaminated soil. pah ... | 2006 | 16213549 |
| screening for bacterial-fungal associations in a south-eastern us salt marsh using pre-established fungal monocultures. | both bacteria and fungi play critical roles in decomposition processes in many natural environments, yet only rarely have they been studied as an integrated community. we examined whether physical associations exist between individual bacterial and fungal species that co-occur on decaying smooth cordgrass, spartina alterniflora, in a south-eastern us salt marsh. fungal-pervaded decaying spartina was used as "bait" for potential bacterial associates. the bundles (infiltrated with one of three dom ... | 2005 | 16332317 |
| comparison of nitrogen fixation activity in tall and short spartina alterniflora salt marsh soils. | a comparison of the n(2) fixers in the tall spartina alterniflora and short s. alterniflora marsh soils was investigated. zero-order kinetics and first-order kinetics of acetylene reduction were used to describe the activity of the n(2) fixers in marsh soil slurries. it was found that the v(max) values were approximately 10 times greater for the n(2) fixers in the tall spartina than in the short spartina marsh when raffinose was used as the energy source. in addition, the (k(s) + s(n)) values we ... | 1977 | 16345213 |
| nitrogen fixation (acetylene reduction) in a salt marsh amended with sewage sludge and organic carbon and nitrogen compounds. | seasonal distribution of nitrogen fixation by spartina alterniflora epiphytes and in surface and soil samples was investigated in a georgia salt marsh which was amended with sewage sludge or with glucose and/or ammonium nitrate. there was no significant difference between the rates of fixation in the unamended and sewage sludge plots. additional perturbation experiments suggested that nitrogen addition indirectly stimulates nitrogen fixation by enhancing spartina production and root exudation. g ... | 1977 | 16345239 |
| effect of the spartina alterniflora root-rhizome system on salt marsh soil denitrifying bacteria. | nitrous oxide (n(2)o) reductase activity was used as an index of the denitrification potential in salt marsh soils. in a short spartina alterniflora marsh, the seasonal distribution of n(2)o reductase activity indicated a causal relationship between s. alterniflora root-rhizome production and the denitrification potential of the soil system. the relationship was not discerned in samples from a tall s. alterniflora marsh. to further examine the in situ plant-denitrifier interaction in the short s ... | 1978 | 16345288 |
| role of the salt marsh grass spartina alterniflora in the response of soil-denitrifying bacteria to glucose enrichment. | long-term incubations of salt marsh soil systems in the presence of glucose resulted in a decrease in the soils' denitrification potential. addition of nitrate or the presence of living spartina alterniflora reversed this effect, indicating that spartina, through the establishment of an oxidized rhizosphere where nitrification can occur, enables the denitrifying bacteria to adequately compete with the less energetically efficient components of the anaerobic soil microbial community. | 1979 | 16345451 |
| tracer analysis of methanogenesis in salt marsh soils. | differences in paths of carbon flow have been found in soils of the tall (ts) and short (ss) spartina alterniflora marshes of sapelo island, ga. gaseous end products of [u-c]glucose metabolism were co(2) and ch(4) in the ss region and primarily co(2) in the ts region. sulfate concentration did not demonstrably affect glucose catabolism or the distribution of end products in either zone. [u-c]acetate was converted to co(2) and ch(4) in the ss soils and almost exclusively to co(2) in the ts soils. ... | 1980 | 16345551 |
| mineralization of detrital lignocelluloses by salt marsh sediment microflora. | specifically radiolabeled c-(cellulose)-lignocellulose and c-(lignin)-lignocellulose were isolated from labeled cuttings of spartina alterniflora (cordgrass) and pinus elliottii (slash pine). these were used to estimate the rates of mineralization to co(2) of lignocelluloses of estuarine and terrestrial origin in salt marsh estuarine sediments. the lignin moiety of pine lignocellulose was mineralized 10 to 14 times more slowly than that of spartina lignocellulose, depending on the source of inoc ... | 1980 | 16345647 |
| comparing time course profiles of immediate acetylene reduction by grasses and legumes. | the time course profiles of c(2)h(2) reduction by intact scirpus olneyi (bulrush), oryza sativa (rice) and spartina alterniflora (cordgrass) with roots in atmospheres of n(2) and 30-day-old glycine max (soybean) in air were all immediately linear. this is the first report of immediately linear rates of c(2)h(2) reduction by grass roots removed from soil. the immediately linear profile of c(2)h(2) reduction by soil-free grass roots was achieved by preventing contact between the roots and air. roo ... | 1981 | 16345684 |
| perfusion method for assaying microbial activities in sediments: applicability to studies of n(2) fixation by c(2)h(2) reduction. | a perfusion method for assaying nitrogenase activity (acetylene reduction) in marine sediments was developed. the method was used to assay sediment cores from spartina alterniflora (salt marsh), zostera marina (sea grass), and thalassia testudinum (sea grass) communities, and the results were compared with those of conventional sealed-flask assays. rates of ethylene production increased progressively with time in the perfusion assays, reaching plateau values of 2 to 3 nmol . g of dry sediment . ... | 1982 | 16346036 |
| biomagnification of aroclor 1242 in decomposing spartina litter. | the accumulation of a polychlorinated biphenyl (pcb) mixture (aroclor 1242) in the process of detritus formation by a shredded marshgrass (spartina alterniflora) under aerobic conditions was monitored in percolators for 4 months at 20 degrees c. dissolved pcb in the influent solution was 14 to 16 mug/liter. parameters monitored in addition to pcb accumulation were co(2) evolution, nh(4) uptake, no(3) production, and total organic nitrogen and carbon in the effluent. an nan(3-) poisoned control s ... | 1982 | 16346096 |
| effects of metals on methanogenesis, sulfate reduction, carbon dioxide evolution, and microbial biomass in anoxic salt marsh sediments. | the effects of several metals on microbial methane, carbon dioxide, and sulfide production and microbial atp were examined in sediments from spartina alterniflora communities. anaerobically homogenized sediments were amended with 1,000 ppm (ratio of weight of metal to dry weight of sediment) of various metals. time courses in controls were similar for ch(4), h(2)s, and co(2), with short initial lags (0 to 4 h) followed by periods of constant gas production (1 to 2 days) and declining rates there ... | 1983 | 16346294 |
| enumeration and localization of n(2)-fixing bacteria associated with roots of spartina alterniflora loisel. | numbers and possible locations of n(2)-fixing bacteria were investigated in roots of spartina alterniflora loisel, which support nitrogenase activity in the undisturbed native habitat. n(2)-fixing bacteria were recovered in cultures both from s. alterniflora roots and from the surrounding sediment, and they formed a greater proportion of the bacteria recovered from root homogenates than from salt-marsh sediment. n(2)-fixing bacteria were recovered in high numbers from the rhizoplane of s. altern ... | 1983 | 16346321 |