Spatial distribution and population structure of palms em um fragmento de Floresta Ombrofila Densa de Terras Baixas no Sul do Brasil

• Published in: Ciência florestal 2015-10, p.817
• Main Authors: Cappelatti, Laura, Schmitt, Jairo Lizandro
• Format: Article
• Language: Spanish
• ISSN: 1980-5098; 1980-5098

In the state of Rio Grande do Sul, the Dense Humid Forest is reduced to less than 5% of its original cover. However, it still has the highest richness of palms in this state, which constitute an important and economically relevant group. Environmental and demographic aspects of plant populations in forest fragments are of great importance for their management and conservation. We conducted a study on the spatial distribution and age structure of five palm species in a forest fragment at the municipality of Tres Cachoeiras, in the north coast of Rio Grande do Sul. We delimited 25 10* 10 m plots and counted the number of individuals in the stages of seedling, juvenile and adult for each palm species. Aggregation Indices were calculated with software SADIEShell. We performed variation partitioning analyses among species distribution and environmental variables canopy openness and soil moisture. A total of 1,443 plants were counted and the most abundant species was Euterpe edulis. The average density was of 57.72 ind. 100 [m.sup.-2]. Three species showed a pattern of "inverse J", which indicated that they have a potential for regenerating in that palm community. The predominant spatial pattern was aggregated (Ia>l) and canopy openness did not influence species abundances. Only the distribution of Bactris se tosa and Geonoma gamiova, both understory species, was explained by soil moisture, suggesting that other abiotic or biotic factors may be influencing the spatial arrangement of the canopy species. Keywords: Altantic rainforest; population ecology, soil humidity; canopy openness. No Rio Grande do Sul, a Floresta Ombrofila Densa esta reduzida a menos de 5% da sua area original, porem, apresenta a maior riqueza de palmeiras do estado, que constituem um grupo importante e economicamente relevante. Aspectos ambientais e demograficos de populacoes de plantas em remanescentes florestais sao de grande importancia para o seu manejo e conservacao. Nos conduzimos o estudo da distribuicao populacional e estrutura etaria de cinco especies de palmeiras em um fragmento florestal no municipio de Tres Cachoeiras, no litoral norte do Rio Grande do Sul. Delimitamos 25 parcelas de 10 x 10 m e contamos o numero de individuos em estadio de plantula, jovem e adulto para cada uma das especies. Calculamos indices de agregacao (Ia) com o programa SADIEShell. Tambem desenvolvemos analises de particao de variacao entre a distribuicao das especies e as variaveis ambientais, abertura de