Autocorrelação espacial e variação temporal na fenologia floral, produção e predação de sementes em Chromolaena odorata (Asteraceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

I investigated the flowering phenology of an important weed in its native habitat, in order to ask if plant phenological parameters, such as onset, end, duration and flowering synchrony, were spatially structured and if so, what are the possible consequences of such structure for plant seed production. Plants were spatially aggregated, at the leveI of both species and genus. I found spatial autocorrelation in several different phenological parameters and in plant fecundity. There was positive autocorrelation mainly between neighbouring plants, which means that floral phenology and plant fecundity are not randomly distributed in space. According to my results, phenological parameters did not affect significantly either seed predation or proportion of viable seeds per plant. Although this result is contrary to most results in previous studies, it may be explained as a density-dependent effect among plants. In this study, seed predation was inversely density dependent as well as spatially autocorrelated. This autocorrelation should be related to spatial structure in the abundance of flower-heads and seeds per plant. Thus, spatial autocorrelation in plant fecundity possibly induced the same effect in seed predator response. Intra-specific and congeneric flower-head abundance probably has an additive effect on seed predation escape

ASSUNTO(S)

ecologia analise espacial (estatistica) cerrados

ACESSO AO ARTIGO

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