Pollination Biology and Environmental Change
Collaborators: Dr. Peter Reich, University of Minnesota, and Dr. Tiffany Knight,
Washington University
Many plant species respond to environmental change, i.e. by shifting their
resource allocation, increasing respiration rates, increasing reproductive output,
etc. My goal is to quantify species-specific responses and the effects of these
responses on plant-animal interactions. I am particularly interested in
plant-pollinator interactions as they are important to plant population dynamics,
and traits that affect them have been shown to respond to environmental change.
This research was conducted at the long-term ecological FACE experiment, known
as the BioCON (Biodiversity, CO2 and N), at the Cedar Creek Natural History
Area. Specifically, I am exploring the effects of environmental change, i.e. elevated
atmospheric CO2 concentrations and N deposition, on the interspecific
interactions of plants with their mutualists and antagonists, i.e. pollinator and
herbivores respectively, in a Free-Air CO2 Enrichment (FACE) experiment that
controls atmospheric CO2 and soil N deposition at a large spatial and temporal
scale. These species include 4 legumes: Amorpha canescens, Lespedeza
capitata, Lupinus perennis, and Petalostemum villosum; and 4 non-legumes:
Achillea millefolium, Anemone cylindrical, Asclepias tuberosa, and Solidago rigida.
Species Distributions.
Historically, the principle of limited similarity conceptualized in the context of
abiotic resources, but plant species are known to compete for pollinators. In
response to a high stress environment, plants often have similar suites of traits
that are thought to be adaptive and are sometimes termed the “stress resistance
syndrome” (SRS). However, these traits also reduce above ground-biomass, which
reduces the competitive ability for pollination success. For my dissertation, I
explored the tradeoff between stress-adaptation and reproductive specialization as
a potential mechanism in the range restriction of three Ozark glade endemic
plants. The Ozark glades are xeric, rocky habitats inhabited by many endemic
species. By comparing these endemic plants to their widespread congeners that
occur on but are not restricted to glades, I tested for a stress-reproduction tradeoff
via field and greenhouse experimental manipulations with three plant species pairs,
each consisting of a glade endemic (i.e., Delphinium treleasei, Echinacea
paradoxa, and Scutellaria bushii) and a more widely distributed congener (i.e., D.
carolinianum, E. pallida, and S. ovata). Through this research, I identified a
mechanism, pollination specialization, contributing to the spatial distribution of
three endemic plants. These results document the importance of interspecific
interactions in the range restriction of glade endemic plants, which previously were
thought to be abiotically determined
.
Major Research Topics:
Determinants of Species Distributions
Pollination Biology
Climate Change
Plant Biology and Environmental Change
Community Responses to Climate Change
Collaborator: Dr. Peter Hoch, Missouri Botanical Garden
Through my research, I seek to understand the historical role of climate
change and its potential future affects on biological systems. While
numerous studies document the temporal and spatial shifts of species in
response to climatic change, few of them consider these shifts in an
ecological and evolutionary context. Using phenological datasets collected by
career and citizen scientists at the Shaw Nature Reserve (SNR) in Gray
Summit, Missouri, I am exploring the contributions of evolutionary history,
species traits, and local habitat to species responses to climate change. In
1937, Dr. Edgar Anderson, a genetist and president of the Missouri Botanical
Garden, conducted weekly surveys of the prominant angiosperms blooming
at SNR. He noted the habitat in which they were found and the phenological
stage of the population. These "phenology walks" were repeated periodically
between 1978 and 2003, and in 2009, my colloborator and I established a
Pollination Biology
The importance of pollinators was recognized well before written history. However, it was
not until 1793 that comparative studies of plant-pollinator interactsion were first conducted
by Christian Sprengel. Charles Darwin (1862) put plant reproduction into an evolutionary
context and formalized the role of pollinators on the evolution of plant morphology. Plant
and animal ecology begain to merge with Heinrich and Raven (1972), which first
introduced the idea of co-evolution and the role of pollination in the diversification of
Angiosperms. However, in 1994, Bronstein still notes that, "It appears that we
simultaneously know both a great deal and not very much at all about mutualisms." For
instance, to date little is known about the pollination biology of the many plant species,
particularly rare or endemic species. However, it is estimated that ninety percent of
angiosperms require pollinators to some degree for fertilization. Despite their importance,
plant-pollinator interactions are often poorly understood and rarely incorporated into
conservation and management strategies. Currently, I am documenting and exploring the
importance of pollinator services for 6 native plant species. I am also interested in the role
of pollination in the management of at-risk and endangered plant species.