Assembleia de pequenos mamíferos em voçorocas no sul de Minas Gerais

Abstract

Forest fragmentation consists of the transformation of a great habitat extension into smaller patches, with consequences to the conservation of several arboreal species. The Ocotea odorifera Vell Rohwer species, of ecological and economic importance and, also, under threat of extinction, is in this situation. The phenologic accompaniment of component individuals from the remaining fragmentation areas is one of the means by which alterations of the biotic and abiotic mediums can be evaluated. The objective of the present study was to analyze and compare, in addition to the phenologic pattern, the population structure, as well as the biometrics patterns of fruits of two natural populations of the species, one population formed of individuals isolated by the fragmentation process (isolated condition) and another formed of individuals in a continuous of seasonal semidecidual forest (continuous condition). For the biometrics analyses we collected length, width and fresh weight values of ripe fruits and, in order to analyze the population structure, the DAP values. The phenologic evaluations were performed between February of 2010 and March of 2012 being used the Fournier activity and intensity indexes and circular statistical analyses. To verify the correlation between the geographical distance and the population synchrony of phenologic events, we performed the Mantel test. Climatological data were still correlated to the phenologic data. There was not statistical difference between the conditions, isolated and continuous, in relation to the biometric pattern of ripe fruits. In isolated condition, a low establishment of the individuals` natural regeneration occurred. The population of the continuous condition, however, presented an inverted J curve. Larger intensities of reproductive events occurred, in general, in the isolated condition. Even with the high production of immature fruits in the isolated condition, predation episodes have befallen the fruits in this condition even before maturation, not statistically differing from the ripe fruit event in the continuous condition. In contrast to the flowering events, for the immature fruit event, the larger the distance between individuals with this event, the higher the synchrony between them, indicating that the species possesses an abortion and/or of self-incompatibility mechanism between close individuals. O. odorifera presented a sub annual flowering and fruiting pattern inserted between main flowering and fruiting periods, of supra annual pattern. The stimulus for unchaining the reproductive events is related to the minimum temperature variable. The continuous condition softened the incidence of the environmental variables on the individuals in this condition.