Shady Business
Know Before
Shading over a creek can be a delicate balance. At the bottom of the food chain, plants and algae need sunlight to grow and produce nourishment for all other organisms. However, shade from tree cover is desperately needed to keep water cool and at a temperature that allows brook trout to grow. Without shade cover, water heats up, making it difficult for Brook Trout to survive. Tree shadows help keep the ground cool so that rainfall runoff from the surrounding area isn’t warmed as it flows overland on its way to the stream.
Get Out The Door
Estimate the canopy cover over the creek
To focus on a particular area to assess, touch your index fingers together and thumbs together, forming a circle. Raise your hands directly overhead and compare the amount of tree cover and sky that you see.
A visual estimation chart can be useful for comparing the percentage of the sky overhead that is covered by tree canopy.
Estimate the ratio of vegetation to visible sky. What category of percentage would this be?
5. Extend your assessment by estimating the percentage of canopy cover that is deciduous (sheds leaves) or coniferous (has needles).
Think Some More
How does canopy cover change throughout the seasons?
What impacts could changing canopy cover have on the stream over a year?
How else do mature trees support a healthy watershed?
Bring Along
visual estimation chart