Welcome back to Ask a Naturalist: your own personal ‘Google’ for all things wild on PEI! Late last week, my inbox started filling up with questions about a yellow film on waters in various locations around PEI, such as these great examples from Paula Dingwell-Vos (Photo 1) and Amy Chandler Cole (Photo 2). This film is the result of a natural, annual spring occurrence: release of tree pollen.
Pollen is comprised of tiny, powdery, slightly sticky grains of genetic material produced by male flowers. Many of our trees are wind pollinated, using a strategy of tossing huge quantities of pollen into the air like confetti, in hopes that some of it will land on female flowers. Some does of course, but far more ends up on land, water bodies, cars, houses, and – much to allergy-sufferers’ dismay – up noses.
Examples of wind-pollenated trees common here on the Island include Alder, Birch, Maple, Oak, Pine, Poplar, Spruce, and Willow. All are in the midst of their spring reproductive season right now, but Birch and Spruce seem to go the extra mile in terms of the amount of pollen produced. A single tree can produce tens of billions of pollen grains! I made a short, slow-motion video to show how much pollen is released by just a few male White Spruce (Picea glauca) flowers. This website platform doesn't support video, but you can find it on my Facebook page on June 5. A still from the video is below (Photo 3).
Pollen is essential for plant reproduction, but it’s beneficial in another way as well. Because it is annual, durable, local, and can be identified to species, pollen preserves a record of our past landscape in much the same way tree rings document the history of a tree. Researchers have taken sediment cores from bogs and estuaries around PEI and used pollen to understand the how our landscape changed since the end of the last ice age, some 12,500 years ago. The pollen you see on the water in these photos will eventually sink to the bottom, continuing the record of vegetation around us.
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