Saturday, August 13, 2016

Fire and Madrones

I paid a revisit to a burned over slope in western Washington. This is a slope that has a southwest aspect, is well within the rain shadow of the Olympic Range, and much of the slope is underlain by sand and gravel. Hence, a dry place that has remained a small prairie (small-prairie-at-discovery-bay).  During a previous winter visit I had noted that madrones were growing from burned stumps. In the two years since the growth has continued. Fire clears out the competing trees and the madrone is well suited for this setting.   

This prairie has been long lived. A sketch image from the Vancouver exploration of this area shows a grass slope at the same location in 1792. I suspect that First Nations use of the area enhanced the frequency of fire.

It is nice the see that madrone (Arbutus menziesii) is thriving here much as it did in 1792 when Archibald Menzies described the tree in detail while visiting the bay. Hard to image he did not walk up this prairie slope examining and collecting plants while visiting in May 1792.


Geoffrey Middaugh said...

You nailed it? Excellent observations. We need more fire into these systems. But.... One comment: the fuel loading it seems to me has been increased significantly by annual grasses (cheat, and its friends) and this can be a threat to the madrone. Any Garry Oak in the area? When the indigenous people put fire into these systems, theses grasses where primarily perennials, but things have changed. This is the same issue in the sagebrush steppe, but more subtle given the precip zone.

Dan McShane said...

I do not know much about my perennials in western Washington. The few invassives I know are not real common at Port Discovery - perhaps it is a bit cut off from those plants - for now. There are invasions of Scotch Broom on some dry slopes south of here. I have not seen any Garry Oak here; sort of surprising given the habitat.