Tree Blog

Habitat Complexity: The Urban Forest Connection
By Matthew Mega, Conservation Director, Seattle Audubon

Most people probably know that all trees are not created equal. A large mature tree that has been around for a multiple decades certainly provides more benefit than a newly planted young tree. Also, trees that grow together to form a grove are probably more beneficial than single specimen trees growing alone. A grove of trees will provide more stormwater management benefits, wind breaks and even aesthetic value.

When it comes to birds and wildlife these concepts become even more important. Certain bird species use different parts of the canopy. Pileated Woodpeckers, for example, tend to forage for food higher in the canopy, where Northern Flickers can often be found on the ground foraging for ants. If we cut down all our mature trees, the Pileated Woodpecker will most likely not survive. Different birds need different vertical habitat complexity for foraging and nesting. As with most things in life the more diversity we can incorporate the better. As we move forward with our Urban Forest Management plan we need to think about ways to incorporate more diversity in the landscape. Planting trees may need to be accompanied by also planting understory plants to increase vertical complexity. There are many things we can do to help promote a healthy and diverse urban forest. Here are a few of my favorites.

• Protect large mature trees, especially conifers.
• Protect large groves of trees like those currently threatened at Waldo Woods in Maple Leaf and Ingraham High School in North Seattle.
• Plant more trees and maintain the trees we have.
• Support a comprehensive urban forest management plan and suit of ordinances that consider the entire forest structure not just individual trees.
• Support and create Backyard Wildlife Sanctuaries. Individual homeowners can help the urban forest and birds by considering turning their backyard into a wildlife sanctuary. More than half of the city is currently single-family homes. Think about how much habitat and urban forest we can create if just a fraction of homeowners participate in the program.

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