The phenological patterns of trees from cerrado, savannah and others seasonally dry forest are not well known and causes for observed periodicity are still obscure; it is said to be caused either by abiotic factors like precipitation or to biotic ones or even both, or also enforced by phylogenetic restriction. In an area of cerrado in the far northeast of Maranhão, the ten most frequent leguminous trees were monitored during twenty-two months. The phenological records were made montly in a sample of ten individuals of each species. Either vegetative or reproductive growth are periodical and seasonal events and in the most species flowering occur during the dry season simultaneous to leaves renewal. Most species produce fruits during the wet period and the propagules are dispersed almost exclusively during the dry one. Tree phenological patterns are discernible: species that renew their leaves and bloom early during the dry season, fruiting and dispersing their propagules at the same season (1), species that renew their leaves late in the dry season, flowering at this time (2) or flowering during the wet season (3), fruiting in the wet period and dispersing their propagules during the following dry one. Periods of vegetative growth and dormancy seem to occur alternately more synchronised with variation of the photoperiod, thermoperiod, and irradiance, than seasonal variations of water availability. Phenological patterns, flowering and fruting periods vary inter and intra families considered as monophyletic, being the only convergence, at this taxonomic level, the synchronisation of thepropagules dispersal in the dry season. The vegetative reproduction does not seem to be a common event in the leguminous species studied.
Phenology; leguminous; cerrado; Maranhão
