October 1, 2020 | Hailey Campbell
There is so much life that exists in the rainforest of the Clayoquot and Barkley Sound region. You will find a vibrant green that is unlike anywhere else on Earth. Amongst the ancient cedars and prehistoric ferns lives ecosystem engineers that are of fundamental importance to our forest. An ecosystem engineer is technically defined as an organism that creates, modifies or maintains an ecosystem. There are few organisms as important as decomposers for maintaining the forest’s ecology. As decomposition in coastal rainforests is quite slow, the rainforest is dependent on the recycling of plants and nutrients by other organisms.
If you have ever taken a walk on a rainy forest day in the Tofino area, you’ve likely had a slimy encounter! These slimy friends are known as Banana slugs (Ariolimax columbianus). I’m pretty sure they’re one of the most aptly named animals because they come in colourations that look just like bananas in all stages of ripeness.
As with many creepy crawlers, Banana slugs are simply misunderstood. They are part of a class of mollusks called gastropods (Greek “stomach foot”) and are classified as detritivores, meaning they consume and gather nutrients from decaying organic matter. Banana slugs can be found on rainy forest days, munching away on detritus (dead organic matter) like fallen leaves, mushrooms, and animal scat, recycling this food into nutrient-dense waste. Banana slugs also play an important role in dispersing the spores of mycorrhizal fungi (Greek “fungus root”) which form a symbiotic (mutually beneficial) relationship with nearly all forest plants. Thousands of mycorrhizal species occur in our forests. Douglas fir (Pseudotsuga menziesii) alone has associations with over 2000 species of fungi.
Speaking of fungi, what is there not to love about them? They just look so cool! Fungi are also one of the few organisms that can break down cellulose and lignin, making fungi essential to nutrient cycling and forest regeneration. The mushrooms that pop up after a rainstorm are there to spread their spores in the damp forest. When the spores germinate, they begin to grow underground branching filaments called hyphae, as the hyphae continue to grow, they will fuse to form mycelium. The mycelium forms an underground fungal network which serves as an extension of the plant’s root system, transporting water, carbon, nitrogen, and other nutrients. In return the plant is the primary energy source for the fungus, providing sugars from photosynthesis. Fungi are essential for both tree decomposition and growth!
It’s quite interesting how detritivores, which we cannot always see, have such a profound effect. Decomposers, like fungi and banana slugs, perfectly demonstrate the interconnectedness of the forest inhabitants. They provide essential nutrients for the growth of new organisms and are the foundation of the cyclical processes that maintain life in the forest. We are incredibly grateful to share our home with the amazing organisms here in the Clayoquot and Barkley Sound Region where our forest ecosystems are teeming with biodiversity.
Hailey Campbell interned at the Raincoast Education Society in Summer 2020. You can get in touch to talk more about detritivores and decomposition!