Pollen proves beneficial for northern lakes

Mark Graham, a PhD student from the Department of Biological Sciences at the U of A, has shown for the first time the benefits of pollen on boreal lakes. Rich in nutrients, pollen is an essential component of plant fertilization but few think of its importance to fertilize lakes. Wind-dispersed pollen in early summer is not only visually striking, but it can represent a substantial pulse of nutrients to northern lakes.

Graham's research team found that plankton responded strongly to additions of pollen in experimental enclosures, located along the shorelines of three boreal lakes in northwestern Ontario's Experimental Lakes Area. “Specifically, pollen subsidized the lake water nutrient levels and in turn, promoted the abundance of plankton,” said Graham, who is working with Dr. Rolf Vinebrooke in the U of A's Freshwater Biodiversity Laboratory. “Our findings strongly suggest that pollen is an important linkable between terrestrial and aquatic ecosystems in northern environments.”

By increasing the availability of plankton, an important food resource for forage fish, the production of harvestable sport fish may also rise, all thanks to pollen.

Since climate also affects annual pollen production predicted climate change scenarios could affect the productivity of northern lakes by altering the magnitude and timing of delivery of this important source of forest-derived nutrients, said Graham.