Phenological study of Cactaceae in the dry enclave of Tatacoa, Colombia

A one-year phenological study of three columnar cacti, Stenocereus griseus (Haw) Britton & Rose, Pilosocereus sp., Cereus hexagonus (L.) Mill., and a decumbent cactus Monvillea cf. smithiana (Britton & Rose) Backeberg., was c arried out in the Andean arid region of La Tatacoa, Colombia. Pollinators a nd/or dispersers of the cacti species also were studied monthly, and fecal samples were collected for the identification of pollen and seeds. The flow ering of all species was prolonged and showed bimodal, multimodal, or irreg ular patterns. Fruiting in all species also was prolonged and followed flow ering with a lag of less than two months. Although there were no simple cor relations between rainfall and flowering or fruiting, flower production dur ing the dry season was higher for S. griseus, while Pilosocererus sp. and C . hexagonus showed higher flower production during the wet season. Fruit pr oduction was also seasonal, with higher production during the wet season fo r S. griseus and C. hexagonus. The patterns of flowering and fruiting in M. cf smithiana showed no relationships with dry and wet seasons. The bats Gl ossophaga longirostris, Carollia perspicillata, Sturnira lilium, the birds Melanerpes rubricapillus (Picidae) and Mimus gilvus (Mimidae), and moths of the family Sphingidae, were identified as pollinators and/or fruit consume rs of these cacti species.