Ecologia reprodutiva de Copaifera langsdorffii Desf. (FABACEAE)

Abstract

Copaifera langsdorffii Desf. (Fabaceae) is a arboreal tropical species with supra annual fructification and from 10 to 15 m of height, attaining 35 m. The pattern phenologyc and plant’s size are characteristics that can affect the number and the size of the produced seeds, being also in the predation of the same ones. The variation of the number e the size of produced seeds, caused by the pattern phenologic and the plant’s size has direct consequences reproductive success of the species. Therefore, the objective of this work was characterize any aspects of the reductive ecology of C. langsdorffii. The chapter I had like objective to analyze the reproductive strategy of C. langsdorfii between and inside of years of high and short reproductive investment, testing the hypothesis of trade-off size/number of seeds. So, we supposed that: (i) in the year high reproductive investment the plant produce larger number of seed with smaller size when compared with year of short investment; (ii) inside of the same reproductive event there are an inverse relationship between the number and the size of seeds produced of plant and (iii) the size of plant influences the results of trade-off size/number of seeds. Were selected 33 reproductive individuals in 2008 and 30 individuals in 2011 for data collection. The results of this work demonstrate that as larger number of seeds for plants smaller the size of produced seeds. That effect was only visible inside of the same reproductive event. Were observed that the production of seeds varies in function of the reproductive year and the size of plant. In 2008 were observed that as larger the plants, larger the number and the size of produced seeds. In 2011, short plants produced more seeds while bigger individuals produced larger seeds. The capacity of change the reproductive strategy in function of the corporal size can represent a competitive advantage of the specie, promoting its full distribution for different environment. The chapter II were appraised the relationship between the size of seeds, the germination and the performance of the seedlings, testing the follow prediction: (i) larger seeds present greater percent of germination; (ii) smaller seeds present short time of germination; (iii) larger seeds produced seedlings more vigorous. In 2011 were selected 30 individuals of C. langsdorffii in which were random collect 300 fruits in the long of the canopy for determination of the biometry of seeds. The seed were allocated in tray germination using vermiculite like substratum. To characterize the vigour of the seedlings, after the fall on the cotyledons the seedlings were removed of the substratum for the determination of the length and the dry weight of the aerial part and root system. The size of the seeds affected the percent of germination. However the result were different from the expected, why small seeds presented larger percent of germination. The time of germination was different between the classes of size. Shorter seeds presented smaller time of germination has larger seeds, corroborating the prediction (ii). Thereby waited, the results demonstrated that bigger seed produce seedlings with larger initial size. The fact of short seeds presented larger percent of germination and germinate more fast favors the colonization of the transitory habitats, however larger seeds form seedlings more vigorous, benefiting the establishment in stable habitats. The chapter III was tested three hypotheses: (i) hypothesis satiation of predators that predict smaller percent of predation in years of higher production of fruits, (ii) hypothesis of recourse concentration that predict larger attack in stains of more concentrated resource and (iii) hypothesis of architecture the plant that predict larger attack of herbivores in plants architecturally more complex. In 2008 were selected 35 reproductive individuals, and in 2011 others 30 individuals that input in reproductive state were for data collection. The production of seeds of Copaifera langsdorffii varied between the years of study, being the number of produced seeds approximately 26.44% larger in 2008. The resulted of this study show that a percent of predation of seeds of C. langsdorffii were 98.42% larger in year of shorter production of seeds, sustaining hypothesis satiation of predators. The percent of seeds predated were smaller in the plants that produced larger number of seeds. Therefore ours data weren’t capable to support hypothesis of recourse concentration. The plant size and seed size produced affected positively the percentage of predation, both in the year as high in years of low resource availability. This study highlights two important aspects: first, the irregular supra-annual fructification results in survival of a larger number of seeds; and second, the seed predators should select patches of better quality resources as a way to produce more offspring