As you look around Tobit’s Trace you will notice a number of large trees, and some small saplings which were recently planted. We humans like trees. They look nice. They provide a shady place to sit and enjoy life. But what role do trees play in the health of streams?

Just as we like to rest under a shady tree, it turns out that shade helps other species also. Shade keeps the area under the tree cool and moist so that the smaller trees, shrubs and grasses can thrive. This undergrowth creates habitats for mammals, reptiles, amphibians, and insects. While some species of birds build their nests low to the ground, more make their homes in the branches of the trees. Some trees, like burr oaks, provide acorns which are food for squirrels and other animals.

Trees provide shade for the stream, which helps the stream maintain a higher level of dissolved oxygen. Fish breathe the oxygen dissolved in the water through their gills. Woody debris from trees which falls into streams offers habitats for macroinvertebrates, fish, reptiles, and amphibians. Bacteria and fungi from dead leaves and branches are food for some stream creatures.

Perhaps most importantly, trees help slow erosion and absorb runoff and pollution like nitrates. Deep tree roots keep soil stabilized and healthy so it can act as a filter. This keeps silt and chemicals from flowing directly into the stream.