Ecological and Evolutionary Characteristics of New England's Buzz Pollinated Flora
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Authors
Curran, Bridget
Date
2022-05
Type
Thesis
Language
en_US
Keywords
Pollination syndromes, floral characteristics, vibratile dehiscence, angiosperms, buzz pollinated species
Alternative Title
Abstract
Description
Pollination syndromes are sets of floral characteristics that have
evolved to attract specific pollinator groups for successful reproduction. Buzz
pollination is a specialized form of vibratile dehiscence whereby a pollinator
must produce a vibration to expel pollen from the anther. This is thought to
occur in approximately 6% of angiosperms as an evolutionary adaptation to
economize pollen, and we now know it occurs in approximately 3% of New
England species. Unlike other pollination syndromes (e.g., moth,
hummingbird, etc.) buzz pollinated species possess a relatively broad range of
perianth morphologies. Buzz pollination has been studied in tropical and
laboratory settings, but community-level studies are few and the breadth of
morphological and ecological variation in New England is poorly understood.
With my research, I tested the hypothesis that buzz pollinated species have a
broad geographic distribution across New England habitats (as opposed to
being restricted to one of a few special habitats) and that differences in
phenology serve to reduce competition for pollinators. Second, I tested
whether there are groups of plant species with similar floral morphologies
associated with specific foraging behavior.
We used online databases, published literature, and herbarium
specimens to determine the number of buzz pollinated species in New
England. Spatial analyses of georeferenced herbarium records were used to
construct a species distribution model and annotated iNaturalist observations
were summarized to determine species’ phenologies. We used linear
regression, multiple factor analysis, and analysis of variance to better
understand the relationships between anther morphology and several other
floral and environmental characteristics. Additionally, we recorded buzz
pollination frequency, amplitude, and duration for a small subset of plant
species in the field to determine whether buzzing characteristics were
associated with specific floral forms.
We find that 89 species of buzz pollinated plants occur throughout
almost every habitat in New England (though primarily in anthropogenic
habitats), that divergence in flowering times occurs in some (not all) habitats,
and that peak flowering time for buzz pollinated species occurs during the
months of June and July. We find a close relationship between anther length and specific perianth morphologies, and a negative correlation between pore
diameter and anther length. We also find significant differences in buzzing
characteristics among several species. Because buzz pollinated plant species
occur in a wide variety of habitats and range from common to rare, basic
knowledge on how bees are interacting with these species in New England will
foster a greater understanding of community interactions and consequences of
disturbances like habitat fragmentation and type conversion. Future research
on plant phenology and how differences in flowering times relate to the
selective pressures acting on plant-pollinator resources will provide insight on
the evolutionary trajectory of this syndrome.