Forests and Green Infrastructure - NC NEMO

Table of Contents

1. Home
2. Forests and Stormwater
3. Types of Forests
4. Interaction of forest types
5. Development within Forests
6. What is a Watershed?
7. What happens when it rains?
8. Why is stormwater runoff a problem?
9. Green Infrastructure
10. Benefits of Forests
11. Ecosystem Services
12. Those elusive tax revenues
13. How to move forward

Types of Forests

How do we define forests?

We aren't talking about individual trees, or about street trees. These are important and contribute to the tree canopy of a city. Although valued for aesthetics and positive effects on property values, and even for wildlife functions and cooling effects, street trees do not provide the functions that a forest provides.

The urban forest has more than 64 housing units per square, and often includes our neighborhoods and greenways. You might also call it the suburban forest. This forest does provide more function than street trees. It should be protected and managed and expanded by replanting, but due to already present infrastructure and development, it is not as good at providing the functions of larger stands of trees.

The exurban forest has 16-64 housing units per square mile

The rural forest has fewer than 16 housing units per square mile

You can consider the exurban and rural forests as "outside of town"

Here is a picture from google maps. In it, you can see a busy downtown area to the right, suburbia to the right of that and exurban and rural forests to the center and left.

We'll look at some zooms now.

Here are 2 pictures of urban forests. The one on the top does have more trees, less houses, but both have more than 64 housing units per square acres. This is the basically the forest in town that consists of street trees, backyard trees, parks, and greenways. It certainly provides benefits, such as cooling, wildlife habitat and property values, some water retention, and with large enough greenway corridors, it can connect the exurban and rural forests, but it doesn't provide the attributes we think of in a forest, such as soil structure, nutrient cycling, and water resource potential. It does need to be managed

I'll mention some important points about urban forest management later on.

Here is a photo of the exurban forest, 16-64 houses per square mile.

This forest retains many of the intrinsic characteristics and benefits that we associate with a forest.

And here is a rural forest. There are less than 16 homes per square mile. This is a forest by anyone's standards.