Putting pollination quality into analyses of floral ecology: testing syndromes through pollinator performance

Pollination;Pollinators;Pollination by insects;Pollination by animals;Plant ecology

King, Caroline ; Willmer, Pat ; Willmer, Pat

University:University of St Andrews

Department:Biology (School of)

关键词: Pollination;    Pollinators;    Pollination by insects;    Pollination by animals;    Plant ecology;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/3219/CarolineKingPhDThesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

Over recent years, the extent of specialised and generalised plant-pollinatorrelationships, and the predictive powers of floral traits (often grouped into “pollination syndromes”) as indicators of the most effective pollinators of plant species, have beenquestioned. Such studies, however, have used proxies such as visitation frequency ratherthan direct measurements of pollinator effectiveness (PE). The main objective of this thesiswas to test the predictive powers of various pollination syndromes using a specific measureof PE: single-visit stigmatic pollen deposition (SVSPD).Six different classical pollination syndromes were tested, using 13 different plantspecies from tropical and temperate habitats, and in the case of flowers typical of thehummingbird, hoverfly, bee, oil flower and long-tongued insect syndromes, the expectedpollinators were the most effective at a single-visit scale. For generalist pollination syndromeflowers, not all observed visitors were significant pollinators, and the species studied werenot as broadly generalised as their visitor assemblages would suggest.In all 13 plant species, pollinator performance could appear consistent withinfunctional visitor groups but was variable between visitor species, and in almost all cases notall of the observed visitors were effective pollinators. The pollinator performance proxies ofvisit duration and feeding behaviour were neither significantly, nor consistently, related toPE. Visit duration was not an accurate indicator of pollinator performance on its own, thoughit was useful when combined with SVSPD to define pollinator performance at a given timescale, for example per hour, per day or per season. My findings suggest that the results ofrecent “pollination” networks and webs, based on visitors but not necessarily pollinators,should be treated with caution.SVSPD therefore proved to be an effective and relatively simple direct measure ofPE, confirming the predictive powers of pollination syndromes, and giving further insight intothe extent of specialisation and generalisation.