English: Sequoia sempervirens driftwood in Shorttail Gulch, near Bodega Bay, California. These large diameter logs spent enough time exposed to wave action to round their contours before being driven into the mouth of a narrow ravine by storm surf. Sequoia's high tannin content is resistant to decay, so these logs retain structural strength for decades. Storm flows within the gulch are insufficient to move the logs back to sea. This unique habitat at the mouths of small estuaries of the California coast is threatened by the diminished quantity of large Redwood logs available in flood waters since the logging of aboriginal forests.