Humans aren’t the only ones finding it hard to stop and smell the roses. Scientists at the University of Virginia have discovered that air pollution can significantly decrease the fragrance of flowers, and thereby impede pollinating insects’ ability to follow a bloom’s scent trail. The researchers believe this decrease could play a factor in the declining population of pollinators, particularly bees, which rely on nectar for food.
The 2008 study found that in less-polluted eras, such as the 1800s, a flower’s scent molecules could travel as far as 1,200 metres. However, in today’s polluted environments, molecules may spread no more than 200 to 300 metres, often making it difficult for pollinators to find blooms. “Air pollution destroys the aroma of flowers by as much as 90 per cent compared to periods before automobiles and heavy industry,” says professor and study co-author Jose D. Fuentes.
Not only are nectar-dependent insects adversely affected, but so too are the flowers, which rely on pollination to proliferate. —Sandra MacGregor
What you can do to aid pollinators:
- Plant a diversity of nectar- and pollen-producing species that provide blooms from early spring through fall.
- Include indigenous plants.
- Avoid the use of pesticides.
- Include larval host plants for butterflies (see “Plants to Attract Butterflies” on page 58 for a list).
- Join Pollination Canada’s Citizen Science project and monitor the pollinators that visit your garden (see pollinationcanada.ca).
- Support the North American Pollinator Protection Campaign (see nappc.org).
Serviceberry (Amelanchier spp.) from Zone 2
Dogwood (Cornus spp.) Zone 2
Wild strawberry (Fragaria virginiana) Zone 3
Wild geranium (Geranium maculatum) Zone 4
Oregon grape (Mahonia aquifolium) Zone 5
Redcurrant (Ribes sanguineum) Zone 6
Violet (Viola canadensis) Zone 4
Hyssop (Agastache scrophulariifolia) Zone 5
Sunflower (Helianthus spp.)
Blazing star (Liatris spicata) Zone 4
Bergamot (Monarda fistulosa) Zone 4
Black-eyed Susan (Rudbeckia hirta) Zone 3
Broad-leaved stonecrop (Sedum spathulifolium) Zone 6
Stiff goldenrod (Solidago rigida) Zone 4
Culver’s root (Veronicastrum virginicum) Zone 3