Saturday, January 15, 2011

Why We Need Green Roofs

Florida's forests and wetlands bountifully stretch across the state, historically providing an uninterrupted swatch of green to migrating birds and other wildlife.

The same holds true for many other states here in the US and other nations.

When Europeans first arrived in the new world tall forests of trees, vines and shrubs stood, having grown over hundreds if not thousands of years.

Slowly and persistently with population growth, the volumetric green became horizontal green.

Ardea alba, Great White Egret, Orlando, Florida
Working with my son Ruairi last year on his entry for the state history fair, I stopped in Deland to pick up a copy of a DVD documenting the cutting of Florida's great cypress forests.

One of the elderly volunteers told me the story of and showed me photographs of a cypress tree, Taxodium distichum, cut and laying in the swamp waiting to be chained to a steamboat and taken to the sawmill.  The cypress stump measured 25' (7.62 M) in diameter.  The tree required three or four thousand years to grow and one week to fell.

Of the hundreds of thousands of acres of ancient native longleaf pine and cypress trees stretching across the state, all but two or three were logged.  Two ancient cypress trees, named 'The Senator' and 'Lady Liberty' are preserved in a small Seminole County Park, each several thousand years in age.

With the forests gone and wetlands filled, concrete and asphalt spread across the landscape.

Today, wildlife and birds no longer have uninterrupted corridors for travel and like the Ardea alba illustrated above resort to the concrete.

Mother nature though is resilient.  The egret was a juvenile, a youngster maybe six months or so old but was making the best of the urban jungle.  Finding a fast food restaurant and the left over fries, the bird seemed happy.

Plants across the roofs of Florida, the US and the world could never replace the forests we've cut.  But they could however serve to provide a level of habitat now missing in the cities.

Green roofs have been touted as energy savers.  I believe their real value is in restoring volumetric green back to the urban core.  Once green roofs appear then habitat is found, stormwater cleaned, a sense of place created, carbon is sequestered, food can be grown, community is strengthened and fresh oxygen replaces smog.

And tree frogs and lizards will be a healthier snack than the fries for the egret.

Happy Green Roofing!


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