, Volume 39, Issue 1, pp 15–35 | Cite as

Nitrogen enrichment during decomposition of mangrove leaf litter in an east African coastal lagoon (Kenya): Relative importance of biological nitrogen fixation

  • B. OHOWA
  • R.G. RAO


In situ decomposition of senescent leaves of twoabundant mangrove species (Rhizophora mucronataLamarck and Ceriops tagal (Perr) C.B. Rob),enrichment of nitrogen and activity of dinitrogenfixing bacteria during decomposition were investigatedduring both rainy and dry seasons in a tropicalcoastal lagoon (Gazi, Kenya). Rates of leafdecomposition were higher for R. mucronata thanfor C. tagal and were highest, for both species,during rainy season. Rates of decomposition, expressedas percentage dry mass loss, over a decompositionperiod of 50 days was: C. tagal (rainy season),69%; C. tagal (dry season), 27%; R.mucronata (rainy season), 98%; and R.mucronata (dry season), 48%. High rainfall anddiurnal tidal inundation appear to enhance the leafdecomposition process. Maximum rates of nitrogenfixation were 380 nmol N2 h-1 g-1 dw forC. tagal (rainy season), 78 nmolN2 h-1 g-1 dw for C. tagal (dryseason), 390 nmol N2 h-1 g-1 dw for R. mucronata (rainy season) and 189 nmolN2 h-1 g-1 dw for R. mucronata (dry season). Although N2 fixation rates werehighest during rainy season, total nitrogenimmobilised in the leaves was highest during the dryseason. Biological nitrogen fixation can account forbetween 13 to 21% of the maximum nitrogen immobilisedin the decaying mangrove leaves. Nitrogen fixation, asa source of allochthonous nitrogen, sustains anitrogen input to the mangrove ecosystem, which addssignificantly to the nitrogen input through leaflitterfall.

decomposition leaf litter mangrove nitrogen fixation 


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  1. Benner R & Hodson RE (1985)Microbial degradation of the leachable and lignocellulosic components of leaves and wood from Rhizophora manglein a tropical mangrove swamp. Marine Ecology Progress Series 23: 221–230Google Scholar
  2. Benner R, Peele ER & Hodson RE (1986) Microbial utilization of dissolved organic matter from leaves of the red mangrove Rhizophora mangle, in the Fresh Creek estuary, Bahamas. Estuarine, Coastal and Shelf Science 23: 607–619Google Scholar
  3. Boonruang P (1984) The rate of degradation of mangrove leaves, Rhizophora apiculataBl. and Avicennia marina(Forsk) Vierh. at Phuket Island, western peninsular of Thailand. In: Soepadmo E, Rao AN & Mackintosh DJ (Eds) Proceedings of the Asian Symposium on Mangrove Environment, Research and Management, 25-29 August 1980, Kuala Lumpur(pp 200–208). University of Malaya and UNESCOGoogle Scholar
  4. Boto KG & Robertson AI (1990) The relationship between nitrogen fixation and tidal exports of nitrogen in a tropical mangrove system. Estuarine, Coastal and Shelf Science 31: 531–540Google Scholar
  5. Brock TCM (1984) Aspects of the decomposition of Nymphoides peltata(Gmel.) O. Kuntze (Menyanthaceae). Aquatic Botany 19: 131–156Google Scholar
  6. Constantinides M & Fownes JH (1994) Nitrogen mineralization from leaves and litter of tropical plants: Relationship to nitrogen, lignin and soluble polyphenols concentrations. Soil Biology and Biochemistry 26(1): 49–55Google Scholar
  7. Fell JW, Master IM & Wiegert RG (1984) Litter decomposition and nutrient enrichment. In: Moss ST (Ed) The Biology of Marine Fungi (pp 239–251). Cambridge University Press, CambridgeGoogle Scholar
  8. Flores-Verdugo FJ, Day JW & Briseno-Duenas R (1987) Structure, litterfall, decomposition, and detritus dynamics of mangroves in a Mexican coastal lagoon with an ephemeral inlet. Marine Ecology Progress Series 35: 83–90Google Scholar
  9. Gallardo A & Merino J (1992) Nitrogen immobilization in leaf litter at two mediterranean ecosystems of SW Spain. Biogeochemistry 15: 213–228Google Scholar
  10. Gallin E, Coppejans E & Beeckman H (1989) The mangrove vegetation of Gazi Bay (Kenya). Bulletin de la Société Royale de Botanique de Belgique 122: 197–207Google Scholar
  11. Gotto JW & Taylor BF (1976) N2 Fixation associated with decaying leaves of the red mangrove (Rhizophora mangle). Applied and Environmental Microbiology 31(5): 781–783Google Scholar
  12. Hardy RWF, Holsten RD, Jackson ED & Burns RC (1968) The acetylene-ethylene assay for nitrogen fixation: Laboratory and field evaluation. Plant Physiology 43: 1185–1207Google Scholar
  13. Hemminga MA, Slim FJ, Kazungu J, Ganssen GM, Nieuwenhuize J & Kruyt NM (1994) Carbon outwelling from a mangrove forest with adjacent seagrass beds and coral reefs (Gazi Bay, Kenya). Marine Ecology Progress Series 106: 291–301Google Scholar
  14. Hicks BJ & SilvesterWB (1985) Nitrogen fixation associated with the New Zealand mangrove (Avicennia marina(Forsk.) Vierh.var.resinifera (Forst. f.) Bakh.). Applied and Environmental Microbiology 49(4): 955–959Google Scholar
  15. Kazungu J, Dehairs F & Goeyens L (1993) Distribution of nutrients and particulate organic material in Gazi Bay. In: Woitchik AF (Ed) Dynamics and Assessment of Kenyan Man grove Ecosystems (pp 175–193). Commission of the European Communities, Project TS2-0240-C (GDF), Final ReportGoogle Scholar
  16. Lee KH, Moran MA, Benner R & Hodson E (1990) Influence of soluble components of red mangrove (Rhizophora mangle) leaves on microbial decomposition of structural (lignocellulosic) leaf components in seawater. Bulletin of Marine Science 46(2): 374–386Google Scholar
  17. Mann FD & Steinke TD (1992) Biological nitrogen fixation (acetylene reduction) associated with decomposing Avicennia marinaleaves in the Beachwood Mangrove Nature Reserve. South African Journal of Botany 58(6): 533–536Google Scholar
  18. Mariotti A, Sougoufara B & Dommergues YR (1992) Estimation of nitrogen fixation using the natural abundance method in a plantation of Casurina equisetifolia(Forst.). Soil Biology and Biochememistry 24(7): 647–653Google Scholar
  19. McClanahan TR (1988) Seasonality in East Africa's coastal waters. Marine Ecology Progress Series 44: 191–199Google Scholar
  20. Melillo JM, Naiman RJ, Aber JD & Linkins AE (1984) Factors controlling mass loss and nitrogen dynamics of plant litter decaying in northern streams. Bulletin of Marine Science 35(3): 341–356Google Scholar
  21. Morris JT & Lajtha K (1986) Decomposition and nutrient dynamics of litter from four species of freshwater emergent macrophytes. Hydrobiologia 131: 215–223Google Scholar
  22. Newell SY, Fell JW, Statzell-Tallman A, Miller C & Cefalu R (1984) Carbon and nitrogen dynamics in decomposing leaves of three coastal marine vascular plants of the subtropics. Aquatic Botany 19: 183–192Google Scholar
  23. OdumWE & Heald EJ (1975) The detritus-based food web of an estuarine mangrove community. In: Cronin LE (Ed) Estuarine Research (pp 265–286). Academic Press Inc., New YorkGoogle Scholar
  24. Rao RG, WoitchikAF, Goeyens L, van Riet A, Kazungu J & Dehairs F (1994) Carbon, nitrogen contents and stable isotope abundance in mangrove leaves from an east African Coastal Lagoon (Kenya). Aquatic Botany 47: 175–183Google Scholar
  25. RiceDL(1982) The detritus nitrogen problem: new observations and perspectives fromorganic geochemistry. Marine Ecology Progress Series 9: 153–162Google Scholar
  26. Rice DL & Tenore KR (1981) Dynamics of carbon and nitrogen during the decomposition of detritus derived from estuarine macrophytes. Estuarine, Coastal and Shelf Science 13: 681–690Google Scholar
  27. Robertson AI, Alongi DM & Boto KG (1992) Food chains and carbon fluxes. In: Robertson AI & Alongi DM (Eds) Tropical Mangrove Ecosystems, Coastal and Estuarine Studies 41 (pp 293–326). American Geophysical UnionGoogle Scholar
  28. Ruwa RK (1993) Zonation and distribution of creek and fringe mangroves in the semi-arid Kenyan coast. In: Lieth H & Al Masoom A (Eds) Towards the Rational Use of High Salinity Tolerant Plants, Vol. 1 (pp 97–105)Google Scholar
  29. Slim FJ & Gwada P (1993) The mangrove vegetation. In: Woitchik AF (Ed) Dynamics and Assessment of Kenyan Mangrove Ecosystems (pp 6–34). Commission of the European Communities, Project TS2-0240-C (GDF), Final ReportGoogle Scholar
  30. Steinke TD & Charles LM (1986) In vitrorates of decomposition of leaves of the mangrove Bruguiera gymnorrhizaas affected by temperature and salinity. South African Journal of Botany 52(1): 323–328Google Scholar
  31. Steinke TD & Ward CJ (1987) Degradation of mangrove litter in the St. Lucia Estuary as influenced by season and exposure. South African Journal of Botany 53(5): 323–328Google Scholar
  32. Tam NFY, Vrijmoed LLP & Wong YS (1990). Nutrient dynamics associated with leaf decomposition in a small subtropical mangrove community in Hong Kong. Bulletin of Marine Science 47(1): 68–78Google Scholar
  33. Turner GL & Gibson AH (1980) Measurements of nitrogen fixation by indirect means. In: Bergersen FG (Ed) Methods for Evaluating Biological Nitrogen Fixation (pp 111–138). Wiley, New YorkGoogle Scholar
  34. Twilley RR, Lugo AE & Patterson-Zucca C (1986) Litter production and turnover in basin mangrove forests in south west Florida. Ecology 67(3): 670–683Google Scholar
  35. Van derValk AG & Attiwill PM(1984) Acetylene reduction in anAvicenniamarinacommunity in Southern Australia. Australian Journal of Botany 32: 157–164Google Scholar
  36. White DS & Howes BL (1994) Nitrogen incorporation into decomposing litter of Spartina alterniflora. Limnology and Oceanography 39(1): 133–140Google Scholar
  37. Zuberer DA & Silver WS (1978) Biological Dinitrogen Fixation (Acetylene Reduction) associated with FloridaMangroves. Applied and Environmental Microbiology 35(3): 567–575Google Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

    • 1
  • B. OHOWA
    • 2
    • 2
  • R.G. RAO
    • 1
    • 1
    • 1
  1. 1.Laboratory for Analytical ChemistryBelgium
  2. 2.Vrije Universiteit BrusselBrusselsBelgium

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