Dubakella soil series is the name given to a reddish-brown stony loam soil which has developed on ultramafic rock containing magnesium minerals such as serpentine or asbestos.[1] This soil occurs from southwestern Oregon south to the Coast Ranges of California near Healdsburg, and it also is found in the Sierra Nevada mountains and foothills.[2]
In common with other ultramafic soils, Dubakella has a poor balance of nutrients which does not allow the vegetation it supports to match the luxuriance seen on adjacent non-ultramafic sites. Jeffrey Pine is usually the most common tree, accompanied by Douglas-Fir, Incense-Cedar, and Sugar Pine—all in open, somewhat stunted stands. Stunting may be less severe in areas which have been dusted with nutrient-bearing volcanic ash. In some areas, as at Grass Valley and near Nevada City, the less stately Gray Pine is dominant.[3] [4] On the poorest sites vegetation may be held to a chaparral-like state.
In addition to being inferior for forestry and poor for agriculture, Dubalkella may present a health hazard due to presence of asbestos. Any Dubakella land which has been developed or is scheduled in that direction should be tested.[5]