Abstract
Rates of nitrogen fixation in seagrass beds (Zostera capricorni) were determined with15N and reduction of acetylene in intact cores of sediment and seagrass. There was good agreement in the results from the two techniques, with a molar ratio of 3∶1.9 ethylene: ammonia produced. Fixed nitrogen was rapidly utilized by the plants, with significant amounts of15N found in the roots and rhizomes and 50% of fixed15N apparently translocated to the leaves. Rates of fixation were high in summer (25 to 40 mg N m−2 day−1) and lower in winter (10 mg N m−2 day−1) and were estimated to supply between one-third and one-half of the nitrogen requirements of the seagrass. Rates of nitrogen fixation were greater in the light than in the dark, and in cores of intact seagrass than in defoliated cores, indicating that the bacteria were dependent on organic compounds secreted by the plants.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Boon PI (1986) Nitrogen pools in seagrass beds ofCymodocea serrulata andZostera capricorni of Moreton Bay, Australia. Aquatic Botany 25:1–19
Boon PI, Moritarty DJW, Saffigna PG (1986) Rates of ammonium turnover and the role of amino-acid deamination in seagrass (Zostera capricorni) beds of Morton Bay, Australia. Mar Biol 91:259–268
Bremner JM (1965) Total nitrogen. In: Black CA (ed) Methods of soil analysis. Part 2. Chemical and microbiological properties. American Society of Agronomy, Minneapolis, pp 1149–1178
Brooks RH, Brezonik PL, Putnam HD, Keirn MA (1971) Nitrogen fixation in an estuarine environment: The Waccasassa on the Florida gulf coast. Limnol Oceanogr 16:701–710
Capone DG (1982) Nitrogen fixation (acetylene reduction) by the rhizosphere sediments of the eelgrass,Zostera marina. Mar Ecol Prog Ser 10:67–75
Capone DG (1988) Benthic nitrogen fixation. In: Blackburn TH, Sorensen J (eds) Nitrogen cycling in coastal marine environments. Wiley, New York, pp 85–123
Capone DG, Budin JM (1982) Nitrogen fixation associated with the rinsed roots and rhizomes of the eelgrassZostera marina. Plant Physiol 70:1601–1604
Capone DG, Penhale PA, Oremland RS, Taylor BF (1979) Relationship between productivity and N2 (C2H2) fixation in aThalassia testudinum community. Limnol Oceanogr 24:117–125
Capone DG, Taylor BF (1977) Nitrogen fixation (acetylene reduction) in the phyllosphere ofThalassia testudinum. Mar Biol 40:19–28
Capone DG, Taylor BF (1980) N2 fixation in the rhizosphere ofThalassia testudinum. Can J Microbiol 26:998–1005
Kenworthy WJ, Currin C, Smith G, Thayer G (1987) The abundance biomass and acetylene reduction activity of bacteria associated with decomposing rhizomes of two seagrasses,Zostera marina andThalassia testudinum. Aquatic Botany 27:97–119
Marsho TV, Burchard RP, Fleming R (1975) Nitrogen fixation in the Rhode R. of Chesapeake Bay. Can J Microbiol 21:1348–1356
McRoy CP, Goering JJ, Chaney B (1973) Nitrogen fixation associated with seagrasses. Limnol Oceanogr 18:998–1002
McRoy CP, McMillan C (1977) Production ecology and physiology of seagrasses. In: McRoy CP, Helfferich C (eds) Seagrass ecosystems: A scientific perspective. Marcel Dekker, New York, pp 53–88
Moriarty DJW (1980) Measurement of bacterial biomass in sandy sediments. In: Trudinger PA, Walter MR, Ralph BJ (eds) Biogeochemistry of ancient and modern environments. Australian Academy of Science, Canberra and Springer-Verlag, Berlin, Heidelberg, New York, pp 131–138
Moriarty DJW, Boon PI, Hansen JA, Hunt WG, Poiner IR, Pollard PC, Skyring GW, White DC (1985) Microbial biomass and productivity in seagrass beds. Geomicrobiol J 4:21–51
Moriarty DJW, Iverson R, Pollard PC (1986) Exudation of organic carbon by the seagrassHalodule wrightii and its effect on bacterial growth in the sediment. J Exp Mar Biol Ecol 96: 115–126
Moriarty DJW, Pollard PC (1982) Diel variation of bacterial productivity in seagrass (Zostera capricorni) beds measured by rate of thymidine incorporation into DNA. Mar Biol 72:165–173
O'Donohue MJ, Mac Rae IC, Moriarty DJW (1991) Improved methods for determining rates of acetylene reduction (nitrogen fixation) by heterotrophic bacteria in seagrass sediment. J Microbiol Methods (in press)
Patriquin DG (1972) The origin of nitrogen and phosphorus for the growth of the marine angiospermThalassia testudinum. Mar Biol 15:25–46
Patriquin D, Knowles R (1972) Nitrogen fixation in the rhizosphere of marine angiosperms. Mar Biol 16:49–58
Roberts DG, Moriarty DJW (1987) Lacunal gas discharge as a measure of productivity in the seagrassZostera capricorni, Cymodocea serrulata andSyringodium isoetifolium. Aquatic Botany 28:143–160
Roberts DG, Smith DM (1987) Infrared gas analysis of both gaseous and dissolved CO2 in small-volume marine samples. Limnol Oceanogr 33:135–140.
Smith GW, Hayasaka SS (1982) Nitrogenase activity associated withHalodule wrightii roots. Appl Environ Microbiol 43:1244–1248
Smith GW, Hayasaka SS (1982) Nitrogenase activity associated withZostera marina from a North Carolina estuary. Can J Microbiol 28:448–451
Whiting GJ, Gandy EL, Yoch DC (1986) Tight coupling of root-associated nitrogen fixation and plant photosynthesis in the salt marsh grassSpartina alterniflora and carbon dioxide enhancement of nitrogenase activity. Appl Environ Microbiol 52:108–113
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
O'Donohue, M.J., Moriarty, D.J.W. & Rae, I.C.M. Nitrogen fixation in sediments and the rhizosphere of the seagrassZostera capricorni . Microb Ecol 22, 53–64 (1991). https://doi.org/10.1007/BF02540212
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02540212