Advertisement

Netherland Journal of Aquatic Ecology

, Volume 27, Issue 1, pp 3–9 | Cite as

Microcommunities and microgradients: Linking nutrient regeneration, microbial mutualism, and high sustained aquatic primary production

  • Robert G. Wetzel
Article

Abstract

Nutrient regeneration is essential to sustained primary production in the aquatic environment because of coupled physical and metabolic gradients. The commonly evaluated ecosystem perspective of nutrient regeneration, as is illustrated among planktonic paradigms of lake ecosystems, functions only at macrotemporal and spatial scales.

Most inland waters are small and shallow. Consequently, most organic matter of these waters is derived from photosynthesis of emergent, floating-leaved, and submersed higher plants and microflora associated with living substrata and detritus, including sediments, as well as terrestrial sources. The dominant primary productivity of inland aquatic ecosystems is not planktonic, but rather is associated with surfaces. The high sustained rates of primary production among sessile communities are possible because of the intensive internal recycling of nutrients, including carbon.

Steep gradients exist within these attached microbial communities that (a) require rapid, intensive recycling of carbon, phosphorus, nitrogen, and other nutrients between producers, particulate and dissolved detritus, and bacteria and protists: (b) augment internal community recycling and losses with small external inputs of carbon and nutrients from the overlying water or from the supporting substrata; and (c) encourage maximal conservation of nutrients. Examples of microenvironmental recycling of carbon, phosphorus, and oxygen among epiphytic, epipelic, and epilithic communities are explained. Recalcitrant dissolved organic compounds from decomposition can serve both as carbon and energy substrates as well as be selectively inhibitory to microbial metabolism and nutrient recycling. Rapid recycling of nutrient and organic carbon within micro-environments operates at all levels, planktonic as well as attached, and is mandatory for high sustained productivity.

Keywords

nutrient regeneration primary production gradients 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. BLENKINSOPP S.A., P.A. GABBOTT, C. FREEMAN, and M.A. LOCK, 1991. Seasonal trends in river biofilm storage products and electron transport system activity. Preshwater Biology, 26: 21–34.Google Scholar
  2. BURKHOLDER, J.M., R.G. WETZEL, and K.L. KLOMPARENS, 1990. Direct comparison of phosphate uptake by adnate and loosely attached microalgae within an intact biofilm matrix. Applied and Environmental Microbiology, 56: 2882–2890.PubMedGoogle Scholar
  3. CALDWELL, D.E., 1984 Surface colonization parameters from cell density and distribution. In: K.O. Marshall, Ed., Microbial Adhesion and Aggregation. Springer-Verlag, New York, p. 125–136.Google Scholar
  4. CALDWELL, D.E. and J.R. LAWRENCE, 1986. Growth kinetics ofPseudomonas fluorescens microcolonies within the hydrodynamic boundary layers of surface microenvironments. Microbial Ecology, 12: 299–312.CrossRefGoogle Scholar
  5. CARLTON, R.G. and R.G. WETZEL, 1987. Distribution and fates of oxygen in periphyton communities. Canadian Journal of Botany. 65: 1031–1037.Google Scholar
  6. CARLTON, R.G. and R.G. WETZEL, 1988. Phosphorus flux from lake sediments: Effect of epipelic algal oxygen production. Limnol. Oceanogr., 33: 562–570.Google Scholar
  7. CARLTON, R.G. G.S. WALKER, M.J. KLUG, and R.G. WETZEL, 1989. Relative values of oxygen, nitrate, and sulfate to terminal microbial processes in the sediments of Lake Superior, Journal of Great Lakes Research, 15: 133–140.Google Scholar
  8. CHARACKLIS, W.G. and P.A. WILDERER, Eds., 1989. Structure and Function of Biofilms, Wiley & Sons, Inc., Chichester, 387 pp.Google Scholar
  9. CHARACKLIS, W.G. and K.C. MARSHALL, Eds., 1990, Biofilms. John Wiley & Sons, Inc., New York, 796 pp.Google Scholar
  10. FREEMAN, C. and M.A. LOCK, 1992. Recalcitrant high-molecular-weight material, an inhibitor of microbial metabolism in river biofilms. Applied and Environmental Microbiology, 58: 2030–2033.PubMedGoogle Scholar
  11. GODSHALK, G.L. and R.G. WETZEL, 1984. Accumulation of sediment organic matter in a hardwater lake with reference to lake ontogeny. Bulletin of Marine Science, 35: 576–586.Google Scholar
  12. GOTSCHALK, C.C. and A.L. ALLDREDGE, 1989. Enhanced primary production and nutrient regeneration within aggregated marine diatoms. Marine Biology, 103: 119–129.CrossRefGoogle Scholar
  13. HUTCHINSON, G.E., 1957. A Treatise on Limnology. I. Geography Physics and Chemistry. J. Wiley & Sons, New York 1015 pp.Google Scholar
  14. JØRGENSEN, B.B., 1989. Light penetration, adsorption, and action spectra in cyanobacterial mats. In: Y. Cohen and E. Rosenberg. Eds., Microbial mats: Physiological ecology of benthio microbial communities. American Society for Microbiology, Washington, DC, pp. 123–137.Google Scholar
  15. KOCH, A.L., 1990. Diffusion: The crucial process in many aspects of the biology of bacteria. Advances in Microbial Ecology, 11: 37–70.Google Scholar
  16. LOCK, M.A., R.R. WALLACE, J.W. COSTERTON R.M. VENTULLO, and S.E. CHARLTON, 1984. River epilithon: Toward a structural-functional model. Oikos, 42: 10–22.Google Scholar
  17. LOSEE, R.F. and R.G. WETZEL, 1983. Selective light attenuation by the periphyton complex. In: R.G. Wetzel, Ed. Periphyton of Freshwater Ecosystems. Dev. in Hydrobiol 17: 89–96.Google Scholar
  18. LOSEE, R.F. and R.G. WETZEL, 1988. Water movement within submersal littoral vegetation. Verh. Intern. Ver. Limnol., 23: 62–66.Google Scholar
  19. LOSEE, R.F. and R.G. WETZEL, 1993a. Littoral flow rates within and around submersed macrophyte communities. Freshwater Biology. 29: 7–17.Google Scholar
  20. LOSEE, R.F. and R.G. WETZEL, 1993b. Submersed macrophyte-epiphytic periphyton microscale flow patterns: Hydrodynamics and boundary layer development. Limnol. Oceanogr. (submitted).Google Scholar
  21. MOELLER, R.E. and R.G. WETZEL, 1988. Littoral vs. profundal components of sediment accumulation: Contrasting roles as phosphorus sinks. Verh. Intern. Ver. Limnol., 23: 386–393.Google Scholar
  22. PETERSON, C.G. and N.B. GRIMM, 1992 Temporal variation in enrichment effects during periphyton succession in a nitrogen-limited desert stream ecosystem. J. of the North American Benthological Society, 11: 20–36.Google Scholar
  23. PROSSER, J.I., 1989. Modelling nutrient flux through biofilm communities. In: W.G. Characklis and P.A. Wilderer, Eds., Structure and Function of Biofilms. J. Wiley & Sons, Chichester, pp. 239–250.Google Scholar
  24. RAVEN, J.A., 1970. Exogenous inorganic carbon sources in plant photosynthesis. Biol. Rev., 44: 167–221.Google Scholar
  25. RAVEN, J.A., 1984. Energetics and transport in aquatic plants. Alan R. Liss, Inc., New York, 587 pp.Google Scholar
  26. REVSBECH, N.P., P.B. CHRISTENSEN, and L.P. NIELSEN, 1989. Microelectrode analysis of photosynthetic and respiratory processes in microbial mats. In: Y. Cohen and E. Rosenberg, Eds., Microbial mats: Physiological ecology of benthic microbial communities American Society of Microbiology, Washington, DC, pp. 153–162.Google Scholar
  27. RIBER, H. and R.G. WETZEL, 1987. Boundary layer and internal diffusion effects on phosphorus fluxes in lake periphyton. Limnol. Oceanogr., 32: 1181–1194.Google Scholar
  28. SMITH, F.A. and N.A. WALKER, 1980. Photosynthesis by aquatic plants: Effects of unstirred layers in relation to assimilation of CO2 and HCO3 and to carbon isotopic discrimination. New Phytologist. 86: 245–259.Google Scholar
  29. STOCK, M.S., A.K. WARD, and R.J. DONAHOE, 1993. Living rock: The contribution of endolithic microbial communities to a multi-layered interface in stream ecosystems. Journal of the North American Benthological Society (in press).Google Scholar
  30. WETZEL, R.G., 1983. Limnology. 2nd Edition. Saunders College Publishing. Philadelphia, 860 pp.Google Scholar
  31. WETZEL, R.G., 1990. Land-water interfaces: Metabolic and limnological regulators. Verh. Intern. Ver. Limnol., 24: 6–24.Google Scholar
  32. WIMPENNY, J., 1989. Laboratory model systems for the experimental investigation of gradient communties. In: Y. Cohen and E. Rosenberg. Eds., Microbial mats: Physiological ecology of benthic microbial communities. American Society for Microbiology, Washington, DC, pp. 123–137.Google Scholar

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • Robert G. Wetzel
    • 1
  1. 1.Department of Biological SciencesThe University of AlabamaTuscaloosaUSA

Personalised recommendations