Maple tree at Ponkapoag Golf Course in Canton, in the fall.

There are many different types of trees along the Neponset River. Trees help to keep the river corridor healthy. 

For example, tree roots hold the soil together. Without these roots, the soil would wash-away into the River with the rains, and blow away into the air with the wind. A River with a lot of dirt in its water because of "soil erosion" is a very hard place for a fish or an insect to find food, breathe, or raise babies.

All sizes of trees, shrubbery and plants also slow any water that flows over the land. The water has to find its way around plant stems and tree trunks, over fallen leaves and dried fruits. 

When water moves slowly, it can sink into the thirsty soil. In the soil, the water loses the pollutants it's gathered along its journey, and sinks further and further underground. Eventually, this water joins the "groundwater." Groundwater flows slowly within the soil, invisible to people until it re-appears in ponds, streams, marshes and wells. In this way, trees help to keep our ponds, streams, marshes and wells clean and full of water.

What kind of pollutants do you think water gathers from streets and parking lots, sidewalks and lawns? Car oil, candy wrappers, road salt, and fertilizer, are a few. 

If trees, bushes and little plants weren't in the soil, what do you think would happen to the polluted water that's flowed over our streets and yards? It would end up right in the River, unfiltered! The River would become contaminated. In places where there are all shapes and sizes of plants, water slows down and sinks into the soil, where the pollutants sit for a while. Over time, many of these pollutants are broken-down by organisms so tiny we can't see them, except with a microscope ("microorganisms").

Trees also shade the river, keeping the water temperature and oxygen levels just right for fish and baby insects. 

And, the leaves and twigs, fruits, insects, little animals and fungi that fall from trees provide food for animals in the River. 

Trees and shrubs also make great homes for wildlife like insects, birds, reptiles and mammals.

How can you identify a tree?

You can look at a tree's buds, flowers, fruit, leaves, bark, height and shape, fallen leaves and fruit, to identify it. It's also very helpful to look at the other kinds of plants that are growing around the tree; they often give a strong hint toward the kind of tree you're looking at. Some plants need very similar amounts of sunlight, moisture and nutrients in the soil to grow.

What kind of trees "dominate" the Neponset Watershed?

Deciduous trees, or trees that lose most of their leaves at one time (like Oak trees, in the winter), are dominant in the Neponset River Watershed. 

However, conifers (trees that lose their leaves gradually throughout the year, and have cones as fruit), like White pine and Eastern hemlock, also exist throughout the Neponset Watershed.