Abundance, Survival And Growth Of Ipomoea Pes-caprae (l.) R. Br. (convolvulaceae) Seedlings On Santa Catarina Island, Santa Catarina State, Brazil [abundância, Sobrevivência E Crescimento De Plântulas De Ipomoea Pes-caprae (l.) R. Br. (convolvulaceae) Na Ilha De Santa Catarina, Sc, Brasil]

Seedlings of Ipomoea pes-caprae occurred on nine of the beaches studied (n = 10) at Santa Catarina Island, (State of Santa Catarina) and in 21 monitored patches (n = 30); it did not occur at the smallest beach. Seedling densities varied from 0 to 5.2 m2, and these differences are in part explained by viable seed bank densities. Seedling survival was low (0.6%) considering the 2823 plants monitored over three years. The main causes of death were wave erosion and burial. No seedlings survived at the beach zone (n = 2684). Seedlings survived in the fore dune, in patches of Ipomoea pes-caprae (0.8%, n = 119), in recolonization areas where Ipomoea pes-caprae was partially removed (80.0%, n = 20) and in recent dune areas, which were reconstructed after intense wave erosion (four seedlings observed). Seedling growth was greatest at the latter. Experiments showed that one-month-old seedlings did not tolerate burial in 10 cm of sand. When buried by 5 cm of sand, 50.0% of the seedlings survived, but these had fewer leaves, lower biomass and lower allocation to root and shoot development. All established seedlings of Ipomoea pes-caprae were recruited in a period without wave erosion; habitat stability was a key factor in Ipomoea pes-caprae regeneration.204875885Abreu de Castilhos, J. & Gré, J.C.R. 1997. Praias da Ilha de Santa Catarina: caracterização morfológica e problemas de erosão costeira. Pp. 107-113. In: Colóquio Franco-brasileiro sobre manejo costeiro da Ilha de Santa Catarina. Florianópolis 1977. Florianópolis, UFSCUniversité Bordeux 1Bach, C.E., Seedling survivorship of the beach morning glory, Ipomoea pes-caprae (Convolvulaceae) (1998) Australian Journal of Botany, 46 (1), pp. 123-133Bernardi, H., Cordazzo, C.V., Costa, C.S.B., Efeito de ressacas sobre Blutaparon portulacoides (St. Hill.) Mears, nas dunas costeiras do sul do Brasil (1987) Ciência e Cultura, 39 (5-6), pp. 545-547Bernardi, H., Seeliger, U., Population biology of Blutaparon portulacoides (St. Hill.) Mears on southern Brazilian backshores (1989) Ciência e Cultura, 41 (11), pp. 1110-1113Boorman, L.A. & Fuller, R.M. 1984. The comparative ecology of two sand dune biennials: Lactuca virosa L. and Cynoglossum officinale L. New Phytologist 69: 609-629Castellani, T.T., Folchini, R., Scherer, K.Z., Variação temporal da vegetação em um trecho de baixada úmida entre dunas, Praia da Joaquina, Florianópolis, SC (1995) Insula, 24, pp. 37-72Castellani, T.T., Santos, F.A.M., Fatores de risco à produção de sementes de Ipomoea pes-caprae (2005) Revista Brasileira de Botânica, 28 (4), pp. 773-783Castellani, T.T., Santos, F.A.M., Abundância de ramos reprodutivos e produção de sementes em populações de Ipomoea pes-caprae (L.) R. Br. na Ilha de Santa Catarina, Brasil (2005) Acta Botanica Brasilica, 19 (2), pp. 251-264Castellani, T.T., Scherer, K.Z., Paula, G.S., Population ecology of Paepalanthus polyanthus (Bong.) Kunth: Demography and life history of a sand dune monocarpic plant (2001) Revista Brasileira de Botânica, 24 (2), pp. 123-134De Jong, T.J., Klinkhamer, P.G.L., Population ecology of the biennials Cirsium vulgare and Cynoglossum officinale in a coastal sand-dune area (1988) Journal of Ecology, 76, pp. 366-38

Community Structure, Succession And Invasibility In A Seasonal Deciduous Forest In Southern Brazil

Majority of invasive trees colonize grasslands, shrublands, and temperate forests. Hovenia dulcis is an exception, because it is one of the most pervasive invaders in Brazilian subtropical forests where it has changed their structure and composition. This study has aimed to identify the clues for its success by defining the structural and functional characteristics of plant communities in different stages of succession with and without H. dulcis. Following the general assumptions of invasion ecology, we expected that H. dulcis establishment and invasion success would be significantly higher in early successional communities, with high resource availability and low species richness and diversity, as well as low functional diversity. Contrary to this hypothesis, no differences were found between plant communities invaded and non-invaded by H. dulcis at three different succession stages. No relationship was found between species richness and diversity and functional diversity, with respect to invasibility along the successional gradient. Hovenia dulcis is strongly associated with semi-open vegetation, where the species was found in higher density. The invasion of open vegetation is more recent, providing evidence of the species’s ability to invade plant communities in early successional stages. We concluded that the colonization by H. dulcis was associated with forest openness, but the species is also able to colonize semi-open vegetation, and persist in the successionally more advanced communities