Reproductive Biology of Tropical Lowland Rain Forest Trees. Ii. Pollination Systems

Abstract

The reproductive biology of tree species of a tropical rain forest was investigated to determine the relative frequency and spatial distribution of different types of pollination mechanisms. Species pollinated by medium‐sized to large bees were most frequent, followed by those pollinated by moths, small diverse insects and small bees, in that order. Almost one half the total species were found to have pollinators with wide foraging ranges. Species pollinated by various groups of pollinators were distributed non‐randomly. The greatest diversity of pollination systems was found in the subcanopy. As compared to the subcanopy, pollination mechanisms in the canopy were monotonous, consisting primarily of species pollinated by bees and small diverse insects. The hummingbird‐ and sphingid moth‐pollinated species were found mainly in the subcanopy. The factors underlying the non‐random distribution of pollinators are discussed and the potential implications of such distribution on the forest structure are explored.

Pollination biology in Jacaranda copaia (Aubl.) D. Don. (Bignoniaceae) at the "Floresta Nacional do Tapajós", Central Amazon, Brazil

“…However, selffertility and apomixis have been also described in some woody tropical Bignoniaceae (Costa et al 2004). The extremely low fruit set from open pollination is consistent with other tropical trees (Bawa et al 1985).…”

“…(Gibbs & Bianchi, 1999), Jacaranda macrantha (Bittencourt 1981) and Jacaranda racemosa (Bittencourt Júnior & Semir 2006). Studies over the last two decades have shown that outbreeding and LSI are common features in many tropical trees (Bawa et al, 1985) but seem to be such common features in the Bignoniaceae that a phylogenetic component has been argued to explain such familial clustering (Gibbs & Bianchi 1999). However, selffertility and apomixis have been also described in some woody tropical Bignoniaceae (Costa et al 2004).…”

“…But despite low density and sometimes asynchronous flowering, which have led to misconceptions about the ability of these plants to attract pollinators and have allogamous fruit set (Corner 1954, Fedorov 1966, they do attract efficient long distance pollinators as large solitary or subsocial bees (Bawa et al 1985, Dick et al 2004. For the tropical Bignoniaceae, a diverse assemblage of pollinators seems to have influenced flowering morphology and guaranteed fruit-set of these largely self-incompatible plants (Gentry 1974a, Gibbs & Bianchi 1999, Bittencourt Júnior & Semir 2004, Gottsberger & Silberbauer-Gottsberger 2006.…”

Abelhas generalistas (Meliponina) e o sucesso reprodutivo de Stryphnodendron pulcherrimum (Fabales: Mimosaceae) com florada em massa na Mata Atlântica, BA

“…Em fl orestas tropicais de alta diversidade de árvores, além da baixa mobilidade do polinizador, outros fatores podem aumentar as chances de autopolinização, como a baixa densidade populacional e grandes distâncias entre indivíduos arbóreos co-específicos (Bawa 1974, Bawa et al 1985, Kress & Beach 1994) ou a fl utuação temporal na abundância do polinizador efetivo. Sendo assim, ao contrário da dioicia, a autocompatibilidade ou auto-incompatibilidade parcial aparecem como estratégias que asseguram a produção de sementes via autopolinização, incluindo a geitonogamia (Harder & Barrett 1996), mesmo que com baixa variabilidade.…”

Biologia reprodutiva de Tapirira guianensis Aubl. (Anacardiaceae), uma espécie dióica em mata de galeria do Triângulo Mineiro, Brasil

“…Estudos com espécies dióicas em ecossistemas tropicais mostram forte associação entre a dioicia e a polinização por grande variedade de pequenos insetos generalistas (Bawa 1980a, Bawa et al 1985b, Oliveira 1996, principalmente pequenas abelhas sociais generalistas e moscas (Bawa 1980a, Givnish 1982. Esses grupos de insetos são sensíveis a pequenas variações individuais na disponibilidade de recursos florais (Beach 1981).…”