Lianas da Amazônia Central: relação entre abundância, propagação vegetativa e aspectos filogenéticos

Abstract

Lianas are plants that need support to reach the forest canopy. Some authors suggest that the high local abundance of individuals of some species is due to high reproductive capacity through vegetative means. We evaluated whether vegetative propagation capacity of liana species can explain the relative local abundance of the species, and if this vegetative propagation capacity is correlated with the phylogenetic placement of the studied species. We based liana species selection on relative abundance data for lianas in the 25-ha Reserve at KM 37, in the Biological Dynamics of Forest Fragments Project, Manaus, Brazil (data from Robyn J. Burnham). Priority species were those that formed congener pairs with species showing different levels of abundance, and a spectrum of species that represented the local diversity of lianas. Five individuals were collected of each species with seven replicate cuttings per individual, each with four nodes. The cuttings were planted horizontally in plastic boxes containing a layer of sand covered by a layer of coconut fiber, and maintained in moist conditions for five months in the greenhouse of the National Institute of Amazonian Research, simulating tropical forest conditions. The percentage of survival, percentage rooting, the Index of Regeneration Potential, and the length of the longest root were recorded for each species. The results indicated a significantly positive correlation between vegetative propagation and local relative abundance. Congeneric species showed similar vegetative propagation capacity. Vegetative reproductive capacity was compared within all major evolutionary lineages including lianas, and was highest in the families Fabaceae and Bignoniaceae, which are the two families of greatest abundance in the studied area and generally in neotropical forests.