On Tuesday, October 2nd, things got messy in Outdoor School! We met with Rachel, an environmental science graduate from the University of Guelph and she walked us through a pond study of the Arboretum. She explained how lucky we were to have a “natural museum” connected to the University and described the richness of the wildlife in the Arboretum, particularly in regards to tree life. On our walk down to the pond, we passed a Kentucky coffee tree and Rachel explained the joint project the University had undergone with the African Lion Safari to fertilize the trees. After the extinction of wooly mammoths, the tree lost its natural partner necessary for germination; the Arboretum decided to feed the pods to elephants at the African Lion Safari to see if fertilization was possible using a modern-day partner.
The result was a success according to Rachel, who helped to sort through the piles of poo, and the final germination rate was a whopping 60%. This symbiotic relationship drew parallels in my mind to the important partnership between bees and flowers that we learned about in the aviary. Bees are necessary for the pollination of a variety of plant life (such as ragweed and clover) and are crucial to their survival and inherently our survival. Imagining the impact of losing bees and the devastation that would cause helped to iterate how harmful extinction of any species, including the mammoth, can be. It also emphasized the positive impact of discovering a new germination partner for the Kentucky coffee plant, as it will help to maintain the tree’s population and lower its risk of extinction.
Continuing down the path, Rachel pointed out clumps of decaying leaves she claimed were the product of an unlikely invasive species, the earthworm! That’s right, the wriggly right-hand man of Ontarian gardeners is harmful to our forests! Rachel explained that decomposition in our forests was originally the responsibility of fungi, but that the introduction of the earthworm has resulted in faster decay. Earthworms have led to soil depletion and lower nutrients available to forest trees, as the dead foliage is broken down at a rate the trees cannot keep up with to properly absorb nutrients. It was interesting to be presented with a local example of an “invasive” species after listening to the podcast CBC Ideas: Bioinvasion: Attack of the Invasive Species, hosted by Barbara Nichol. When Rachel was talking I thought about the point Barbara brought up about how humans can be selective in what we choose to view as “bad” invasive species. So-called “ugly” fish like the snakehead can be painted as truly evil and propaganda is created to instill fear and encourage removing them from environments. However, in the case of earthworms, the benefits they provide in cultivating gardens is beneficial enough that we tend to overlook their negative impact as seen by the chorus of “good” that erupted from our class when Rachel asked if earthworms were “good or bad” for the forest.
After carefully rounding a corner with a small patch of poison ivy, our class entered the pond. The trees were slightly wet and the air was damp from fog earlier in the morning. A light mist floated on the water, creating a peaceful scene. With each step down to the water’s edge, our rainboots squelched through the thick mud. Within five minutes of our study, Molly dipped her bucket into the water and with one confident stroke pulled up a bucket containing a frog and a tadpole. It was interesting comparing the differences between the two, as I had never had a chance to study a tadpole up close. The coloration of the tadpole’s body was similar to that of a frog and possessed a leopard pattern. Its upper body was very large in proportion to its tail, and the small fish-like appendage looked almost unnatural.
Later, Kasia and I were investigating a patch of water near the lily pads. We pulled up a bucket of water and were amazed at the quantity and variety of life in such a small volume. Along the surface, dozens of small black daphnia swam in a frenzy. Along the bottom slender damselflies with feathery gills scuttled about, and under a dead leaf, we found the queen of the Canadian pond bugs: the giant water bug. After extracting a larger damselfly and the giant water bug into vials, we showed Rachel and she excitedly shared some facts. She explained that the damselfly lived for only a few hours, its sole purpose in that time to mate, and that the giant water bug was apparently an aggressive predator capable of growing up to 2-3 inches in length. Woah!
Another group caught a frog, and Rachel showed us the proper way to hold him without causing harm. She pointed out two holes behind his eyes and explained these were his ears, and she explained that frogs breath through their skin, hence the importance of handling them with clean hands and respect.
Overall, the day was a success and I was amazed at the variety of life both in and around the pond. I found it incredible how at a closer look life was everywhere in the quiet arboretum, and with someone as knowledgeable as Rachel to guide the way, each new discovery was a learning experience.
CBC Ideas: Bioinvasion: Attack of the Invasive Species, Barbara Nichol, 2014.