The pollination ecology of a Mexican Acacia community. / Raine, N. E.

2001. 242 p.

Research output: ThesisDoctoral Thesis

Published

Abstract

This thesis examines the interactions between patterns of resource availability and insect activity using the pollination ecology of a Mexican Acacia community as a model system. Plants present a number of resources (including pollen and nectar) used by insects, but the extent to which the patterns of resource presentation and the structuring of insect activity patterns influence one another is little known. The patterns of pollen presentation and flower visitation within a community of Acacia species in Chamela, México were studied over three field seasons between 1998 and 2000. Seasonal patterns of flowering and daily patterns of pollen release amongst species appeared to be important in achieving effective pollination in this Acacia community. Pollinator activity patterns tracked the amounts of pollen available in both seasonal and daily time. Data suggest the avoidance of movement by individual shared pollinators between Acacia macracantha and A. angustissima inflorescences, and the associated interspecific pollen flow, could potentially form the basis of a competitive interaction promoting divergence between these species in their daily patterns of pollen release. Spatial and temporal patterns of trophic reward (extrafloral nectar and Beltian bodies) presentation within the canopy of the ant-acacia A. hindsii and activity patterns of its associated ant-guard Pseudomyrmex veneficus were investigated. They revealed that trophic rewards are preferentially invested in the new growth leaves, hence making them the focus of ant guarding activity. During flowering there is potential for antagonistic interactions between the two groups of mutualists upon which this tree relies - pollinators and ant-guards. Despite substantial temporal overlap in the daily activity patterns of ant and pollinators, the potential for ant-pollinator conflict appears to be largely resolved by spatial segregation of the resources used by these two insect groups. In addition, A. hindsii flowers produce an ant-repellent substance that reinforces spatial segregation between ants and pollinators.
Original languageEnglish
QualificationPhD
Awarding Institution
  • University of Oxford
Supervisors/Advisors
  • Stone, G. N., Supervisor, External person
Publication statusPublished - 2001

ID: 1065464