There once were more than 20 different pygmy forests in the Sonoma and Mendocino North Coast area, but now there are only a few, as most were bulldozed in the course of development. The pygmy forest is one of the few places in the world where one can track the complete evolution of soils from their origin to near-depletion. The pygmy forest has a special role to play in illustrating the interdependence of soil and plants in the unique ecosystem formation. Located on the oldest ancient marine terraces, the sandy soils are underlain by an impermeable layer of iron and graywacke sandstone. Over hundreds of thousands of years, acid leached from the trees by rainfall has built up in the infertile soil. Neither plant roots nor water can penetrate the hardpan lying approximately eighteen inches below the soil surface. The white, nutrient-poor, iron-hardpan soil sustains only stunted vegetation, yet the trees may be hundreds of years old. Very few species can eke out a living in this impoverished environment; those that do must struggle mightily. Stands of cypress, pine and even the normally gigantic redwood do not attain normal growth.
The pygmy cypress, Cupressus goveniana pigmaea, is a rare, single-stemmed, shrubby, evergreen tree with slender crowns and scarce silvery branches encrusted with lichens. Leaf sprays are slender and delicate with scale-like leaves occurring in opposite, alternating pairs. Cones are woody, brown to gray, serotinous (late developing) with umbrella-like scales. Pygmy Cypress is often found with Bolander pine bolanderi, but here the pines are mostly Bishop pine Pinus muricata. Other species commonly found in this forest are rhododendron Rhododendron; macrophyllum Gaultheria shallon; manzanita Arctostaphylos; coast chinquapin Chrysolepis chrysophylla; California huckleberry Vaccinium ovatum; Labrador tea Ledum glandulosum; and bracken fern Pteridium aquilinum.