Belowground Interactions Among Salt Marsh Plants and Microorganisms

Interactions Between Macro- and Microorganisms in Marine Sediments

Volumn , Issue , 2013, Pages 61-83

  Lovell, Charles R ^a  

^a UNIVERSITY OF SOUTH CAROLINA   (United States)

Author keywords

Interactions between macro and microorganisms in marine sediments

Indexed keywords

NITROGEN FIXATION; ORGANIC CARBON; REDUCTION; SOILS; SUBMARINE GEOLOGY; SULFUR COMPOUNDS; WETLANDS;

AMERICAN GEOPHYSICAL UNION; MACRO-AND MICROORGANISM; NUCLEOTIDE SEQUENCES; PLANT-MICROBE INTERACTIONS; RHIZOSPHERE MICROBIAL; SPARTINA ALTERNIFLORA; SULFATE REDUCING BACTERIA; TERMINAL ELECTRON ACCEPTORS;

BACTERIA;

EID: 84952785142     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1029/CE060p0061     Document Type: Chapter

References (120)

1. Amann, R. I., W. Ludwig, and K.-H. Schleifer, Phylogenetic identification and in situ detection of individ-ual microbial cells without cultivation. Microbiol. Rev. 59, 143-169, 1995.
2. Armstrong, W., Root aeration in the wetland condition, in Plant Life in Anaerobic Environments, edited by D. D. Hook and R. M. Crawford, pp. 269-298, Ann Arbor Science Series, Ann Arbor, Michigan, 1978.
3. Bagwell, C. E. and C. R. Lovell, Microdiversity of culturable diazotrophs from the rhizoplanes of the salt marsh grasses Spartina alterniflora and Juncus roemerianus. Microb. Ecol. 39, 128-136, 2000a.
4. Bagwell, C. E. and C. R. Lovell, Persistence of selected Spartina alterniflora rhizoplane diazotrophs exposed to natural and manipulated environmental variability. Appl. Environ. Microbiol. 66, 4625-4633, 2000b.
5. Bagwell, C. E., and C. R. Lovell. A DNA-DNA hybridization method for the detection and quantification of specific bacterial taxa in natural environments, in Environmental Microbiology, pp. 169-174, Methods in Biotechnology Series, edited by J. F. T Spencer and A. L. Ragout de Spencer. Humana Press, Totowa, New Jersey, 2004.
6. Bagwell, C. E., Y. M. Piceno, A. Ashbume-Lucas, and C. R. Lovell, Physiological diversity of the rhizos-phere diazotroph assemblages of selected salt marsh grasses. Appl. Environ. Microbiol. 64, 4276-4282, 1998.
7. Bagwell, C. E., M. Dantzler, P. W. Bergholz, and C. R. Lovell, Host specific ecotypic diversity of rhizo-plane diazotrophs of the perennial glasswort, Salicornia virginica and selected salt marsh grasses. Aq. Microb. Ecol. 23, 293-300, 2001.
8. Bagwell, C. E., J. R. La Racque, G. W. Smith, S. W. Poison, M. J. Friez, J. W. Longshore, and C. R. Lovell, Molecular diversity of diazotrophs in ohgotrophic tropical seagrass bed communities. FEMS Microbiol. Ecol. 39, 113-119, 2002.
9. Badziong, W. and R. K. Thauer, Growth yields and growth rates of Desulfovibrio vulgaris (Marburg) grow-ing on hydrogen plus thiosulfate as the sole energy sources. Arch. Microbiol. 117, 209-214, 1978.
10. Bergholz, P. W., C. E. Bagwell, and C. R. Lovell, Physiological diversity of rhizoplane diazotrophs of the saltmeadow cordgrass, Spartina patens. Implications for host specific ecotypes. Microb. Ecol. 42, 466-473, 2001.
11. Bertness, M. D., Fiddler crab regulation of Spartina alterniflora production on a New England salt marsh. Ecology 66, 1042-1055, 1985.
12. Bertness, M. D., Zonation of Spartina patens and Spartina alterniflora in a New England salt marsh. Ecology 72, 138-148, 1991.
13. Bertness, M. D., P. J. Ewanchuk, and B. R. Silliman, Anthropogenic modification of New England salt marsh landscapes. Proc. Natl. Acad. Sci. USA 99, 1395-1398, 2002.
14. Blaabjerg, V. and K. Finster, Sulphate reduction associated with roots and rhizomes of the marine macro-phyte Zostera marina. Aquat. Microb. Ecol. 15, 311-314, 1998.
15. Blackburn, T. H., D. B. Nedwell, and W. J. Wiebe, Active mineral cycling in a Jamaican seagrass sediment. Mar. Ecol. Prog. Ser. 110, 233-239, 1994.
16. Blom, C. W. P. M., Adaptations to flooding stress: From plant community to molecule. Plant Biol. 1, 261-273, 1999.
17. Bodelier, P. L. E., J. A. Libochant, C. W. P. M. Blom, and H. J. Laanbroek, Dynamics of nitrification and den-itrification in root-oxygenated sediments and adaptation of ammonia-oxidizing bacteria to low-oxygen or anoxic habitats. Appl. Environ. Microbiol. 62, 4100-4107, 1996.
18. Bogdahn, M., J. R. Andreesen, and D. Kleiner, Pathways and regulation of N2, ammonium and glutamate assimilation by Clostridium formicoaceticum. Arch. Microbiol. 134, 167-169, 1983.
19. Both, G. J., S. Gerards, and H. J. Laanbroek, The occurrence of chemolithoautotrophic nitrifiers in water-saturated grassland soils. Microb. Ecol. 23, 15-26, 1992.
20. Boyle, C. D. and D. G. Patriquin, Carbon metabolism of Spartina alterniflora Loisel in relation to that of associated nitrogen-fixing bacteria. New Phytol. 89, 275-288, 1981.
21. Bradley, P. M. and J. T. Morris, The influence of salinity on the kinetics of NIL;"1" uptake in Spartina alterni-flora. Oecologia 85, 375-380, 1991.
22. Brandis A. and R. K. Thauer, Growth of Desulfovibrio species on hydrogen and sulphate as sole energy source. J. Gen. Microbiol. 126, 249-252, 1981.
23. Brinson, M. M., and R. R. Christian, Stability of Juncus roemerianus patches in a salt marsh. Wetlands 19, 65-70, 1999.
24. Briske, D. D., T. W. Boutton, and Z. Wang, Contribution of flexible allocation priorities to herbivory toler-ance in C4 perennial grasses: An evaluation with 13C labeling. Oecologia 105, 151-159, 1996.
25. Brix, H., B. K. Sorreli, and P. T. Orr, Internal pressurization and convective gas-flow in some emergent fresh-water macrophytes. Limn. Ocean. 37, 1420-1433, 1992.
26. Brown, M. M., M. J. Friez, and C. R. Lovell, Expression of ni/H genes by diazotrophic bacteria in the rhizosphere of short form Spartina alterniflora. FEMS Microbiol. Ecol. 43, 411-417, 2003.
27. Bruno, J. R, and M. D. Bertness, Habitat modification and facilitation in benthic marine communities, in Marine Community Ecology, edited by M. D. Bertness, S. D. Gaines, and M. E. Hay, pp. 201-218, Sinauer, Sunderland, Massachusetts, 2001.
28. Burke, D. J., E. R Hamerlynck, and D. Hahn, Interactions among plant species and microorganisms in salt marsh sediments. Appl. Environ. Microbiol. 68, 1157-1164, 2002a.
29. Burke, D. J., E. R Hamerlynck, and D. Hahn, Effect of arbuscular mycorrhizae on soil microbial popula-tions and associated plant performance of the salt marsh grass Spartina patens. Plant Soil 239, 141-154, 2002b.
30. Burke, D. J., E. P. Hamerlynck, and D. Hahn, Interactions between the salt marsh grass Spartina patens, arbuscular mycorrhizal fungi and sediment bacteria during the growing season. Soil Biol. Biochem. 35, 501-511,2003.
31. Campbell, R. and M. P. Greaves, Anatomy and community structure of the rhizosphere, in The Rhizosphere, edited by J. M. Lynch, pp. 11-34, John Wiley and Sons Ltd., New York, 1990.
32. Christensen, P. B. and J. Sorensen, Temporal variation of denitrification activity in plant-covered, littoral sediment from Lake Hampen, Denmark. Appl. Environ. Microbiol. 51, 1174-1179, 1986.
33. Christensen, P. B., N. P. Revsbech, K. Sand-Jensen, Microsensor analysis of oxygen in the rhizosphere of the aquatic macrophyte Littorella uniflora (L.) Ascherson. Plant Physiol. 105, 847-852, 1994.
34. Cooke, J. C, R. H. Butler, and G. Mandole, Some observations on the vertical distribution of vesicular arbuscular mycorrhizae in roots of salt marsh grassed growing in saturated soils. Mycologia 85,547-550, 1993.
35. Dacey, J. W. H., How aquatic plants ventilate. Oceanus 24, 43-51, 1981.
36. Dame, R. R, and P. D. Kenny, Variability of Spartina alterniflora primary production in the euhaline North Inlet estuary. Mar. Ecol. Prog. Ser. 32, 71-80, 1986.
37. Davidson, J. L., and R L. Milthorpe, The effect of defoliation on the carbon balance in Dactylis glomerata. Ann. Bot. 30, 185-198, 1966.
38. Devereux, R., M. E. Hines, and D. A. Stahl, Scychng: Characterization of natural communities of sulfate-reducing bacteria by 16S rRNA sequence comparisons. Microb. Ecol. 32, 283-292, 1996.
39. Dicker, H. J., and D. W. Smith, Enumeration and relative importance of acetylene-reducing (nitrogen-fix-ing) bacteria in a Delaware salt marsh. Appl. Environ. Microbiol. 39, 1019-1025, 1980.
40. Drake, H. L., Acetogenesis, acetogenic bacteria, and the Acetyl-CoA "Wood/Ljungdahl" pathway: past and current perspectives, in Acetogenesis, edited by H. L. Drake, pp. 3-60, Chapman and Hall, New York, NewYork, 1994.
41. Drake, H. L., S. L. Daniel, K. Kiisel, C. Matthies, C. Kuhner, and S. Braus-Stromeyer, Acetogenic bacte-ria: what are the in situ consequences of their diverse metabolic versatilities? BioFactors 6, 13-24, 1997.
42. Eleuterius, L. N., Autecology of the black needlerush Juncus roermerianus. Gulf Res. Rep. 7, 339-350, 1984.
43. Emerson, D., J. V. Weiss, and J. P. Megonigal, Iron-oxidizing bacteria are associated with ferric hydroxide precipitates (Fe-plaque) on the roots of wetland plants. Appl. Environ. Microbiol. 65, 2758-2761, 1999.
44. Ferris, M. J., G. Muyzer, and D. M. Ward, Denaturing gradient gel electrophoresis profiles of 16S rRNA-defined populations inhabiting a hot spring microbial mat community. Appl. Environ. Microbiol. 62, 340-346, 1996.
45. Fuchs, G., CO2 fixation in acetogenic bacteria: variations on a theme. FEMS Microbiol. Rev. 39, 81-213, 1986.
46. Gallagher, J. L., Effect of an ammonium nitrate pulse on the growth and elemental composition of natural stands of Spartina alterniflora and Juncus roemerianus. Amer. J. Bot. 62, 644-648, 1975.
47. Gandy, E. L., and D. C. Yoch, Relationship between nitrogen-fixing sulfate reducers and fermenters in salt marsh sediments and roots of Spartina alterniflora. Appl. Environ. Microbiol. 54, 2031-2036, 1988.
48. 14C labeling studies for the operation of the citric acid cycle. Arch. Microbiol. 136, 230-233, 1983.
49. Gibson, G. R., Physiology and ecology of the sulphate-reducing bacteria. J. Appl. Bacteriol. 69, 769-797, 1990.
50. Großkopf, R., S. Stuner, and W. Liesack, Novel euryarchaeotal lineages detected on rice roots and in the anoxic bulk soil of flooded rice microcosms. Appl. Environ. Microbiol. 64, 4983-4989, 1998.
51. Hanson, R. B., Comparison of nitrogen fixation activity in tall and short Spartina alterniflora salt marsh soils. Appl. Environ. Microbiol. 33, 596-602, 1977a.
52. Hanson, R. B., Nitrogen fixation (acetylene reduction) in a salt marsh amended with sewage sludge and organic carbon and nitrogen compounds. Appl. Environ. Microbiol. 33, 846-852, 1977b.
53. Hanson, R. B., Nitrogen fixation activity (acetylene reduction) in the rhizosphere of salt marsh angiosperms, Georgia, USA. Bot. Mar. 26, 49-59, 1983.
54. Herbert, R. A., Heterotrophic nitrogen fixation in shallow estuarine sediments. J. Exp. Mar. Biol. Ecol. 18, 215-225, 1975.
55. Hines, M. E., S. L. Knollmeyer, J. B. Tugel, Sulfate reduction and other sedimentary biogeochemistry in a northern New England salt marsh. Limn. Oceanogr. 34, 578-590, 1989.
56. Hines, M. E., R. S. Evans, B. R. Sharak Genthner, S. G. Willis, S. Friedman, J. N. Rooney-Varga, and R. Devereux, Molecular phylogenetic and biogeochemical studies of sulfate-reducing bacteria in the rhizosphere of Spartina alterniflora. Appl. Environ. Microbiol. 65, 2209-2216, 1999.
57. Hoefnagels, M. H., S. W. Broome, and S. B. Schafer, Vesicular-arbuscular mycorrhizae in salt marshes in North Carolina. Estuaries 16, 851-858, 1993.
58. Howes, B. L. and J. M. Teal, Oxygen loss from Spartina alterniflora and its relationship to salt marsh oxy-gen balance. Oecologia 97, 431-438, 1994.
59. Howes, B. L., J. W. H. Dacey, and D. D. Goehringer, Factors controlling the growth form of Spartina alterniflora: feedbacks between above-ground production, sediment oxidation, nitrogen and salinity. J. Ecol. 74, 881-898, 1986.
60. Hwang, Y.-H. and J. T. Morris, Evidence for hygrométrie pressurization in the internal gas space of Spartina alterniflora. Plant Physiol. 96, 166-171, 1991.
61. Jackson, M. B., and W. Armstrong, Formation of aerenchyma and the processes of plant ventilation in rela-tion to soil flooding and submergence. Plant Biol. 1, 274-287, 1999.
62. Jansen, K., R. K. Thauer, F. Widdel, and G. Fuchs, Carbon assimilation pathways in sulfate-reducing bac-teria. Formate, carbon dioxide, carbon monoxide, and acetate assimilation by Desulfovibrio baarsii. Arch. Microbiol. 138, 257-262, 1984.
63. Jansen, K., G. Fuchs, and R. K. Thauer, Autotrophic CO2 fixation by Desulfovibrio baarsii: demonstration of enzyme activities characteristic for the Acetyl-CoA pathway. FEMS Microbiol. Lett. 28, 311-315, 1985.
64. Karnholz A., K. Kiisel, A. Gossner, A. Schramm, and H. L. Drake, Tolerance and metabolic response of ace-togenic bacteria toward oxygen. Appl. Environ. Microbiol. 68, 1005-1009, 2002.
65. King, G. M., Associations of methanotrophs with the roots and rhizomes of aquatic vegetation. Appl. Environ. Microbiol. 60, 3220-3227, 1994.
66. King, G. M., and M. A. Garey, Ferric iron reduction by bacteria associated with the roots of freshwater and marine macrophytes. Appl. Environ. Microbiol. 65, 4393-4398, 1999.
67. Kirshtein, J. D., H. W. Paerl, and J. Zehr, Amplification, cloning, and sequencing of a nifU segment from aquatic microorganisms and natural communities. Appl. Environ. Microbiol. 57, 2645-2650, 1991.
68. Kolb, W., and P. Martin, Influence of nitrogen on the number of N2-fixing and total bacteria in the rhizos-phere. Soil Biol. Biochem. 20, 41-51, 1988.
69. Kostka, J. R., B. Gribsholt, E. Pétrie, D. Dalton, H. Skelton, and E. Kristensen, The rates and pathways of carbon oxidation in bioturbated saltmarsh sediments. Limnol. Oceanogr. 47, 230-240, 2002a.
70. Kostka, J. E., A. Roychoudhury, and P. van Cappellen, Rates and controls of anaerobic microbial respira-tion across spatial and temporal gradients in saltmarsh sediments. Biogeochemistry 60, 49-76, 2002b.
71. Krone, R. B., Simulation of marsh growth under rising sea levels, in Hydraulics and Hydrology in the Small Computer Age, edited by W. R. Waldrop, pp. 106-115, Hydraulics Division, ASCE, Reston, Virginia, 1985.
72. Küsel, K., H. C. Pinkart, H. L. Drake, and R. Devereux, Acetogenic and sulfate-reducing bacteria inhabit-ing the rhizoplane and deep cortex cells of the sea grass Halodule wrightii. Appl. Environ. Microbiol. 65, 5117-5123, 1999.
73. Küsel, K., A. Karnholz, T. Trinkwalter, R. Devereux, G. Acker, and H. Drake, Physiological ecology of Clostridium glycolicum RD-1, an aerotolerant acetogen from sea grass roots. Appl. Environ. Microbiol. 67, 734-4741, 2001.
74. Laanbroek, H. J. and N. Pfennig, Oxidation of short chain fatty acids by sulfate-reducing bacteria in fresh-water and in marine sediments. Arch. Microbiol. 128, 330-335, 1981.
75. Leaphart, A. B., and C. R. Lovell, Recovery and analysis of formyltetrahydrofolate synthetase gene sequences from natural populations of acetogenic bacteria. Appl. Environ. Microbiol. 67, 1392-1395, 2001.
76. Leaphart, A. B., M. J. Friez, and C. R. Lovell, Formyltetrahydrofolate synthetase sequences from salt marsh plant roots reveal a diversity of acetogenic bacteria and other bacterial functional groups. Appl. Environ. Microbiol. 69, 693-696, 2003.
77. Livingstone, D. C, and D. G. Patriquin, Nitrogenase activity in relation to season, carbohydrates and organic acids in a temperate zone root association. Soil Biol. Biochem. 12, 543-546, 1980.
78. Lovell, C. R., Y. M. Piceno, J. M. Quattro, and C. E. Bagwell, Molecular analysis of diazotroph diversity in the rhizosphere of the smooth cordgrass, Spartina alterniflora. Appl. Environ. Microbiol. 66, 3814-3822, 2000.
79. Lovell, C. R., C. E. Bagwell, M. Czako, L. Marton, Y. M. Piceno, and D. B. Ringelberg, Stability of a rhi-zosphere microbial community exposed to natural and manipulated environmental variability. FEMS Microbiol. Ecol. 38, 69-76, 2001.
80. McClung, C. R., D. G. Patriquin and R. E. Davis, Campylobacter nitrofigilis sp. nov., a nitrogen-fixing bacterium associated with roots of Spartina alterniflora Loisel. Int. J. Syst. Bacteriol. 33,605-612, 1983a.
81. McClung, C. R., P. van Berkum, R. E. Davis, and C. Slogger, Enumeration and localization of N2-fixing bacteria associated with roots of Spartina alterniflora Loisel. Appl. Environ. Microbiol. 45, 1914-1920, 1983b.
82. Mendelssohn, I. A., The influence of nitrogen level, form, and application method on the growth response of Spartina alterniflora in North Carolina. Estuaries 2, 106-112, 1979.
83. Mendelssohn, I. A., and M. T. Postek, Elemental analysis of deposits on the roots of Spartina alterniflora Loisel. Am. J. Bot. 69, 904-912, 1982.
84. Mendelssohn, I. A., and J. T. Morris, Ecophysiological controls on the growth of Spartina alterniflora, in Concepts and Controversies in Tidal Marsh Ecology, edited by N. P. Weinstein and D. A. Kreeger, pp. 59-80, Kluwer, Dordrecht, The Netherlands, 2000.
85. Morris, J. T., The mass balance of salt and water in intertidal sediments: results from North Inlet, South Carolina. Estuaries 18, 556-567, 1995.
86. Morris, J. T., P. V. Sundareshwar, C. T. Nietch, B. Kjerive, and D. T. Cahoon, Responses of coastal wet-lands to rising sea level. Ecology 83, 2869-2877, 2002.
87. Nijburg, J. W., and H. J. Laanbroek, The influence of Glyceria maxima and nitrate input on the composi-tion and nitrate metabolism of the dissimilatory nitrate-reducing bacterial community. FEMS Microbiol. Ecol. 22, 57-63, 1997.
88. Normand, P., and J. Bousquet, Phylogeny of nitrogenase sequences in Frankia and other nitrogen-fixing microorganisms. J. Mol. Evol. 29, 436-447, 1989.
89. Patriquin, D. G., Factors affecting nitrogenase activity (acetylene reducing activity) associated with excised roots of the emergent halophyte Spartina alterniflora Loisel. Aquat. Bot. 4, 193-210, 1978.
90. Patriquin, D. G. and C. R. McClung, Nitrogen accretion, and the nature and possible significance of N2 fixation (acetylene reduction) in a Nova Scotian Spartina alterniflora stand. Mar. Biol. 47, 227-242, 1978.
91. Penhale, P. A. and R. G. Wetzel, Structural and functional adaptations of eelgrass (Zostera marina L.) to the anaerobic sediment environment. Can. J. Bot. 61, 1421-1428, 1983.
92. Pennings, S. C, and M. D. Bertness, Salt marsh communities, Marine Community Ecology, edited by M. D. Bertness, S. D. Gaines, and M. E. Hay, pp. 289-316, Sinauer, Sunderland, Massachusetts, 2001.
93. Piceno, Y. M., P. A. Noble, and C. R. Lovell, Spatial and temporal assessment of diazotroph assemblage composition in vegetated salt marsh sediments using denaturing gradient gel electrophoresis analysis. Microb. Ecol. 38, 157-167, 1999.
94. Piceno, Y. M. and C. R. Lovell, Stability of natural bacterial communities: I. Nutrient addition effects on rhizosphere diazotroph assemblage composition. Microb. Ecol. 39, 32-40, 2000a.
95. Piceno, Y. M. and C. R. Lovell, Stability of natural bacterial communities: n. Plant resource allocation effects on rhizosphere diazotroph assemblage composition. Microb. Ecol. 39, 41-48, 2000b.
96. Postgate, J. R., and H. M. Kent, Diazotrophy within Desulfovibrio. J. Gen. Microbiol. 131, 2119-2122, 1985.
97. Reddy, K. R., W. H. Patrick, Jr., and C. W. Lindau, Nitrification-denitrification at the plant root-sediment interface in wetlands. Limnol. Oceanogr. 34, 1004-1013, 1989.
98. Roden, E. E., and R. G. Wetzel, Organic carbon oxidation and suppression of methane production by micro-bial Fe(III) oxide reduction in vegetated and unvegetated freshwater wetland sediments. Limnol. Oceanogr. 41, 1733-1748, 1996.
99. Rooney-Varga, J. N., R. Devereux, R. S. Evans, and M. E. Hines, Seasonal changes in the relative abun-dance of uncultivated sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of Spartina alterniflora. Appl. Environ. Microbiol. 63, 3895-3901, 1997.
100. Rooney-Varga, J. N., B. R. S. Genthner, R. Devereux, S. G. Willis, S. D. Friedman, and M. E. Hines, Phylogenetic and physiological diversity of sulfate-reducing bacteria isolated from a salt marsh sedi-ment. Syst. Appl. Microbiol. 21, 557-568, 1998.
101. Schauder, R., B. Eikmanns, R. K. Thauer, F. Widdel, and G. Fuchs, Acetate oxidation to C02 via a novel pathway involving reaction of the citric acid cycle. Arch. Microbiol. 145, 162-172, 1986.
102. Smith, C. J., and R. D. DeLaune, Influence of the rhizosphere of Spartina alterniflora Loisel on nitrogen loss from a Louisiana Gulf coast salt marsh. Environ. Exp. Bot. 24, 91-93, 1984.
103. Sorensen, J., D. Christensen, and B. B. Jorgensen, Volatile fatty acids and hydrogen as substrates for sulfate-reducing bacteria in anaerobic marine sediment. Appl. Environ. Microbiol. 42, 5-11, 1981.
104. Staley, J. T., and A. Konopka, Measurement of in situ activities of nonphotosynthetic microorganisms in aquatic and terrestrial habitats. Annu. Rev. Microbiol. 39, 321-346, 1985.
105. Stubner, S., T. Wind, and R. Conrad, Sulfur oxidation in rice field soil: Activity, enumeration, isolation and characterization of thiosulfate-oxidizing bacteria. System. Appl. Microbiol. 21, 569-578, 1998.
106. Sundareshwar, P. V, J. T. Morris, E. K. Koepfler, and B. Fomwalt, Phosphorus limitation of coastal ecosys-tem processes. Science 299, 563-565, 2003.
107. Sundby B., C. Vale, I. Cacador, F. Catarino, M. J. Madureira, and M. Caetano, Metal-rich concretions on the roots of salt marsh plants: Mechanism and rate of formation. Limn. Oceanogr. 43, 245-252, 1998.
108. Teal, J. M. and J. W. Kanwisher, Gas transport in the marsh grass, Spartina alterniflora. J. Exp. Bot. 17, 355-361, 1966.
109. Teal, J. M., I. Valiela, and D. Berlo, Nitrogen fixation by rhizosphere and free-living bacteria in salt marsh sediments. Limnol. Oceanogr. 24, 126-132, 1979.
110. Thompson, J. N, O. J. Reichman, P. J. Morin, M. E. Power, R. W. Sterner, C. A. Couch, L. Gough, R. Holt, D. U. Hooper, F. Keesing, C. R. Lovell, B. T. Milne, M. C. Molles, D. W. Roberts, and S. Y. Strauss, Frontiers of ecology. Bioscience 51, 15-24, 2001.
111. Trimmer, M., K. J. Purdy, and D. B. Nedwell, Process measurement and phylogenetic analysis of the sul-fate reducing bacterial communities of two contrasting benthic sites in the upper estuary of the Great Ouse, Norfolk, UK. FEMS Microbiol. Ecol. 24, 333-342, 1997.
112. Ueda, T., Y. Suga, N. Yahiro, and T. Matsuguchi, Remarkable N2-fixing bacterial diversity detected in rice roots by molecular evolutionary analysis of nifH gene sequences. J. Bacteriol. 177, 1414-1417, 1995.
113. Valiela, I. and J. M. Teal, The nitrogen budget of a salt marsh ecosystem. Nature 280, 652-656, 1979.
114. Vanduin, W. E., J. Rozema, and W. H. O. Ernst, Seasonal and spatial variation in the occurrence of vesicu-lar-arbuscular (VA) mycorrhiza in salt marsh plants. Agricult. Ecosyst. Environ. 29, 107-110, 1990.
115. Ward, D. M., M. J. Ferris, S. C. Nold, and M. M. Bateson, A natural view of microbial biodiversity within hot spring cyanobacterial mat communities. Microb. Molec. Biol. Rev. 62, 1353-1370, 1998.
116. Whiting, G. J., E. L. Gandy and D. C. Yoch, Tight coupling of root-associated nitrogen fixation and plant photosynthesis in the salt marsh grass Spartina alterniflora and carbon dioxide enhancement of nitroge-nase activity. Appl. Environ. Microbiol. 52, 108-113, 1986.
117. Woerner, L. S., and C. T. Hackney, Distribution of Juncus roemerianus in North Carolina tidal marshes: The importance of physical and biotic variables. Wetlands 17, 284-291, 1997.
118. Wood, H. G., and L.G. Ljungdahl, Autotrophic character of the acetogenic bacteria, in Variations in Autotrophic Life, edited by L. L. Barton and J. Shively, pp. 201-250, Academic Press, San Diego, California, 1991.
119. Zehr, J. P. and D. G. Capone, Problems and promises of assaying the genetic potential for nitrogen fixation in the marine environment. Microb. Ecol. 32, 263-281, 1996.
120. Zehr, J. P., M. T. Mellon, and W. D. Hioms, Phylogeny of cyanobacterial nifH genes: evolutionary impli-cations and potential applications to natural assemblages. Microbiology 143, 1443-1450, 1997.