A pioneering community in dunes: does anthropization modify floristic composition?

A zona costeira do Piaui tem sido fortemente impactada nos ultimos anos pela intervencao antropica – processos urbanisticos, turismo predatorio, descarte inadequado de residuos solidos – principalmente sobre as areas de dunas. Os impactos negativos refletem nos estratos vegetais, dentro os quais se destacam as formacoes herbaceas, alterando sua estrutura e dinâmica, comprometendo o equilibrio do ecossistema. Assim, este estudo avaliou as diferentes formacoes herbaceas em dunas em estado de conservacao e antropizacao, assim como, identificou a diversidade de especies presentes nos dois ambientes, as especies dominantes, comuns e indicadoras de efeitos antropogenicos. A pesquisa procedeu na cidade de Luis Correia, litoral do Piaui, nas proximidades das praias do Coqueiro e Macapa, onde foram realizadas as coletas das dunas antropizadas e conservadas, respectivamente. Foi empregado o metodo de parcelas, totalizando 200 parcelas em 4 dunas. O material vegetal foi coletado, identificado e incorporado em herbario. Nas dunas antropizadas, foi encontrado um total de 12 especies, distribuidas em 11 generos, correspondentes a 11 familias. Ja nas dunas nao antropizadas, foi possivel obter um total de 23 especies, distribuidas em 20 generos, correspondentes a 13 familias. As dunas se caracterizaram pela formacao de campos. As familias mais representativas foram Fabaceae e Poaceae. As especies mais significativas quanto a sua dominância, foram Richardia grandiflora Britton, e Euploca polyphylla (Lehm) J.I.M. Melo & Semir, sendo consideradas indicadoras de efeitos de antropizacao, utilizadas em estudos de anatomia foliar, onde foi possivel a identificacao de estruturas que permitem a sua adaptacao a ambientes de restinga. Este estudo contribuiu para o conhecimento da diversidade botânica de herbaceas em dunas do litoral piauiense, fornecendo dados para subsidiar pesquisas subsequentes de fisiologia e anatomia de especies indicadoras de antropizacao. A B S T R A C T The coastal zone of Piaui has been heavily impacted in recent years by anthropic intervention - urban processes, predatory tourism, inadequate disposal of solid waste - mainly on the dune areas. The negative impacts reflect in the vegetal strata, in which the herbaceous formations stand out, altering its structure and dynamics, compromising the balance of the ecosystem. Thus, this study evaluated the different herbaceous formations in dunes in a state of conservation and anthropization, as well as, identified the species diversity present in both environments, the dominant species, common and indicative of anthropogenic effects. The research was carried out in the city of Luis Correia, on the coast of Piaui, near the beaches Coqueiro and Macapa, where the plant samples were collected in the anthropized and preserved dunes. The plots method was used, with 200 plots in 4 dunes. The plant material was collected, identified and incorporated in herbarium. In the anthropic dunes, a total of 12 species were found, distributed in 11 genera, corresponding to 11 families. In the non-anthropic dunes, it was possible to obtain a total of 23 species, distributed in 20 genera, corresponding to 13 families. The dunes were characterized by the formation of fields. The most representative families were Fabaceae and Poaceae. The most significant species for their dominance were Richardia grandiflora Britton, and Euploca polyphylla (Lehm) J.I.M. Melo & Semir, being considered indicators of anthropization effects, used in foliar anatomy studies, where it was possible to identify structures that allow their adaptation to restinga environments. This study contributed to the knowledge of the herbaceous botanical diversity in dunes of the Piaui coast, providing data to support subsequent researches on the physiology and anatomy of species indicative of anthropization. Keywords: leaf anatomy, anthropization, phytosociology, herbaceous, restinga.