Abstract
A perennial population of Ruppia maritima in a permanent lagoon in the Evros Delta grew from April to October and reproduced during summer. Numbers of rhizome and stem internodes increased in spring–summer and in late summer–autumn, revealing two successive periods of both horizontal and vertical expansion; leaf density increased continuously until October (78,210 leaves m−2). An annual population in a temporary lagoon grew and reproduced from May to August, and died afterwards leaving seeds as the habitat temporarily dried. Numbers of rhizome internodes sharply increased only in August, while numbers of stem internodes increased in June, indicating that a slow horizontal expansion was followed by a fast and brief vertical expansion; subsequently a second intense horizontal expansion occurred; leaf density peaked in August (58,080 leaves m−2). Several characteristics increased after mid-spring, attaining similar maximum values in annual and perennial populations. However, the perennial population had larger leaves and higher root biomass, but lower reproductive organ biomass. Rhizome, stem and leaf biomass increased sharply in August (113.2 g dw m−2) in the annual population and progressively up to October (167.8 g dw m−2) in the perennial population. Using principal component analysis, growth and reproduction were found to be mainly affected by temperature.
References
Bigley, R.E. and P.G. Harrison. 1986. Shoot demography and morphology of Zostera japonica and Ruppia maritima from British Columbia, Canada. Aquat. Bot.24: 69–82.10.1016/0304-3770(86)90118-XSearch in Google Scholar
Bird, K.T., B.R. Cody, J. Jewett–Smith and M.E. Kane. 1993. Salinity effects on Ruppia maritima L. cultured in vitro. Bot. Mar.36: 23–28.10.1515/botm.1993.36.1.23Search in Google Scholar
Brock, M.A. 1982. Biology of the salinity tolerant genus Ruppia L. in saline lakes in South Australia II. Population ecology and reproductive biology. Aquat. Bot.13: 249–268.10.1016/0304-3770(82)90063-8Search in Google Scholar
Brock, M.A. 1983. Reproductive allocation in annual and perennial species of the submerged aquatic halophyte Ruppia. J. Ecol.71: 811–818.10.2307/2259594Search in Google Scholar
Calado, G. and P. Duarte. 2000. Modeling growth of Ruppia cirrhosa. Aquat. Bot.68: 29–44.10.1016/S0304-3770(00)00104-2Search in Google Scholar
Dawes, C.J., D. Hanisak and W.J. Kenworthy. 1995. Seagrass biodiversity in the Indian river lagoon. Bull. Mar. Sci.57: 59–66.Search in Google Scholar
Dunton, K.H. 1990. Production ecology of Ruppia maritima L. s.l. and Halodule wrightii Aschers. in two subtropical estuaries. J. Exp. Mar. Biol. Ecol.143: 147–164.10.1016/0022-0981(90)90067-MSearch in Google Scholar
Flores-Verdugo, F.J., J.W. Day Jr, L. Mee and R. Briseno-Duenas. 1988. Phytoplankton production and seasonal biomass variation of seagrass Ruppia maritima L., in a tropical Mexican lagoon with an ephemeral inlet. Estuaries11: 51–56.Search in Google Scholar
Grøntved, J. 1958. Underwater macrovegetation in shallow coastal waters. J. Cons. Cons. Int. Explor. Mer.24: 32–42.10.1093/icesjms/24.1.32Search in Google Scholar
Harrison, P.G. 1982. Seasonal and year-to-year variations in mixed intertidal populations of Zostera japonica Aschers. and Graeb. and Ruppia maritima L. s.l. Aquat. Bot.14: 357–371.10.1016/0304-3770(82)90109-7Search in Google Scholar
Husband, B.C. and M. Hickman. 1985. Growth and biomass allocation of Ruppia occidentalis in three lakes, differing in salinity. Can. J. Bot.63: 2004–2014.Search in Google Scholar
Jerling, L. and A. Lindhe. 1977. Zonation of soft-bottom vegetation at Asko, C. Sweden. Sven. Bot. Tidskr.70: 303–309.Search in Google Scholar
Kantrud, H.A. 1991. Widgeongrass (Ruppia maritima L.): literature review. Fish and Wildlife Research 10. United States Department of the Interior and Wildlife Servise, Washington DC. pp. 58.Search in Google Scholar
Kevrekidis, T. 2004. Seasonal variation of the macrozoobenthic community structure at low salinities in a Mediterranean Lagoon (Monolimni Lagoon, Northern Aegean). Int. Rev. Hydrobiol.89: 407–425.10.1002/iroh.200310703Search in Google Scholar
Kiørboe, T. 1980. Production of Ruppia cirrhosa (Petagna) Grande in mixed beds in Ringkøbing Fjord (Denmark). Aquat. Bot.9: 135–143.10.1016/0304-3770(80)90014-5Search in Google Scholar
Koch, E.W. and C.J. Dawes. 1991. Ecotypic differentiation in populations of Ruppia maritima L. germinated from seeds and cultured under algae-free laboratory conditions. J. Exp. Mar. Biol. Ecol.152: 145–159.10.1016/0022-0981(91)90212-FSearch in Google Scholar
Koch, E.W. and U. Seeliger. 1988. Germination ecology of two Ruppia maritima L. populations in southern Brazil. Aquat. Bot.31: 321–327.10.1016/0304-3770(88)90020-4Search in Google Scholar
Menéndez, M. 2002. Net production of Ruppia cirrhosa in the Ebro Delta. Aquat. Bot.73: 107–113.10.1016/S0304-3770(02)00012-8Search in Google Scholar
Milchakova, N.A. 1989. Comparative description of the structure of Zostera spp. populations in the pure and mixed phytocenoses in the Kazachya Bay. Ecologiya moray31: 26–30. (in Russian).Search in Google Scholar
Milchakova, N.A. 1999. On the status of seagrass communities in the Black Sea. Aquat. Bot.65: 21–32.10.1016/S0304-3770(99)00028-5Search in Google Scholar
Muus, B.J. 1967. The fauna of Danish estuaries and lagoons. Meddr. Danm. Fisk- og Havunders. pp. 316.Search in Google Scholar
Pulich, W.M. 1985. Seasonal growth dynamics of Ruppia maritima L.s.l. and Halodule wrightii Aschers. in southern Texas and evaluation of sediment fertility status. Aquat. Bot.23: 53–66.10.1016/0304-3770(85)90020-8Search in Google Scholar
Santamaría, L. and M.L.M. Hootsmans. 1998. The effect of temperature on the photosynthesis growth and reproduction of a Mediterranean submerged macrophyte, Ruppia drepanensis. Aquat. Bot.60: 69–188.Search in Google Scholar
Schutten, J., J.A. van der Velden and H. Smit. 1994. Submerged macrophytes in the recently freshened lake system Volkerak-Zoom (the Netherlands) 1987–1991. Nutrient dynamics and biological structure in shallow fresh water and brackish lakes. Hydrobiologia275/276: 207–218.10.1007/BF00026712Search in Google Scholar
Van Vierssen, W.C., C.M. van Kessel and J.R. van Der Zee. 1984. On the germination of Ruppia taxa in Western Europe. Aquat. Bot.19: 381–393.10.1016/0304-3770(84)90050-0Search in Google Scholar
Verhoeven, J.T.A. 1979. The ecology of Ruppia-dominated communities in Western Europe. I. Distribution of Ruppia representatives in relation to their autecology. Aquat. Bot.6: 197–268.10.1016/0304-3770(79)90064-0Search in Google Scholar
Verhoeven, J.T.A. 1980. The ecology of Ruppia dominated communities in Western Europe. III. Aspects of production, consumption and decomposition. Aquat. Bot.8: 209–253.Search in Google Scholar
Zar, J.H. 1984. Biostatistical analysis. 2nd edition. Prentice-Hall Inc, N.J. pp. 718.Search in Google Scholar
©2004 by Walter de Gruyter Berlin New York