Factors affecting pollinator movement and plant fitness

NATTERO J, MALERBA R, MEDEL R, COCUCCI AA

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Año: 2011 vol. 296 p. 77 - 85

0378-2697

The rate of pollen exchange within and among flowers may depend on pollinator attraction traits such as floral display size and flowering plant density. Variation on these traits may influence pollinator movements, pollen receipt, and seed number. To assess how floral display size and flowering plant density affect parameters of pollinator visitation rate, pollen receipt per flower, seed number per fruit and the between-plant pollinator movements, we studied the self-incompatible plant, Nierembergia linariifolia. Per-flower pollinator visitation rate and bout length increased linearly with floral display size. Pollen receipt per flower increased linearly with flowering plant density. For seed number per fruit, a polynomial model describing an increased seed number per fruit at low density and a decreased seed number per fruit at high density provided a significant fit. Per-flower pollinator visitation rate did not associate with pollen receipt per flower and seed number per fruit. Bees visited more frequently plants located near to the centre of the population than plants located at the periphery. Both floral display size and flowering plant density increased the chance of a plant of being chosen as the centre of the pollinator foraging area. These results suggest that even though large floral displays and high flowering plant density are traits that attract more pollinators, they may also reduce potential mate diversity by restricting pollen movement to conspecific mates that are closely located.