A nurse roof?
Nurse logs are common in the rain forests of the Olympic Peninsula. However, until this week I had never noticed that two old cabins at NAD/Soroptomist Park in Bremerton have what could be considered nurse roofs (see photo). The roof in the picture won’t go through the complete nurse-log cycle, but it will be interesting to see how tall the Western Hemlocks that sprouted there get before it collapses or the building is torn down.
A nurse log is a fallen tree that provides a raised platform above the forest floor for new seedlings to grow on. Insects, fungi, and microbes help break down the old tree, which provides nutrients and moisture for a variety of plants. As the seedlings grow their roots grow around and through the log to the soil beneath it. Eventually the old tree decays completely leaving a new generation of trees in its place.
NAD/Soropomist Park consists of 54 wooded acres located between Kitsap Way and SR 3. Before the area became a park, it was a naval ammunition depot (or NAD) that dated back to the 1930’s. Today the park belongs to the city of Bremerton.
The building in the photo was probably the residence of the officer in charge when the ammunition depot was an active facility. When I first moved to Bremerton in the 1970’s, the park’s caretaker lived in the cabin. The building has since been condemned for structural reasons, so it is unlikely that its roof will ever be replaced.
A matching cabin located on the opposite side of Austin Drive also has a nurse roof. It has more ferns growing out of its moss-covered shakes than the cabin in the photo. However, the small trees it supports aren’t as large. The building is still in use and houses a store run by the Boy Scouts of America. When I asked the store’s manager what it was like to be inside on a rainy day, she said that it didn’t leak. She added that there are plans to replace its roof when money is available.
Austin Drive is a heavily used shortcut through the park that connects Kitsap Way and SR 3. The cabins are located just before the stop sign at the Kitsap Way end of Austin Drive. I wonder how many drivers notice the trees on the roofs as they drive through the park.
Mud Bay Blog 
Kind of like, “Pigeons on the grass, alas.” This is, “Trees on the roof, poof.”
Here succulents are planted on roofs. While not self starting like the hemlocks with a shallow root structure and water of course they are more likely to survive.