Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2018-2019)

This proposal is for two interdigitating projects: 1) Community ecology on plant/pollinator interactions across the advancing ecotone of Boreal forest to Arctic tundra in relation to climatic warming and 2) Micrometeorological studies on mechanisms and functional significance of heat gain in flowers.
Project 1 comprises field studies on the importance of insect pollination in plant sexual reproduction coupled with bipartite connectance analyses with weighting botanical importance (i.e. in pollination and plant sexual reproduction) and entomological importance (bionomic utility of floral resources to foraging and reproduction). Bipartite connectance patterns relate the diversity of pollinators with the diversity of plants. They are descriptive of such mutualistic communities, but with additional information can be explanatory and predictive. Environmental changes, resulting from warming, are especially severe in the Arctic with the treeline marching north. Pollination systems are known to respond to environmental stress, but studies across the treeline have not been made. The Churchill, MB area straddles the treeline, is well known botanically and entomologically, and standardized plots for this study are in place. Through a quantifiable measures of community ecology through bipartite connectance patterns weighted to consider the plant and insect biota through pollination is expected to elucidate present mutualisms, explain their importance and possible allow for predictions for future Arctic terrestrial biodiversity.
Project 2 will investigate the extent, mechanisms and functional significance of heat accumulation in flowers for pollination, pollen tube growth, fertilization, embryogenesis and fruit/seed production. Flowers passively variously accumulate solar heat. Well known are diaheliotropic (spectacularly parabolic bowls and other forms) radiation collectors. Some are hollow microgreenhouses (campions, louseworts), others pubescent (willows), yet others (hanging bells) capture convective warmth from the ground. Additional heat is thought to contribute significantly to floral maturation, pollination through to seeding. New mini-instrumentation (with thermocouples or thermistors) allows continuous recording of microclimates in tiny spaces. Comparisons of temperatures (within and between flowers, and ambient air), change in plant stature, intrafloral phenology (duration of flowering, rates of androecial development and pollen shedding, rates of gynoecial development and stigmatic receptivity), rates of development of pollen tubes in stylar tissue, duration from anthesis to fertilization, and duration to fruit/seed maturation and release. Field experiments in years 1 and 2 will give way to detailed indoor studies (greenhouses, growth chambers and laboratory).