SO BE FREE - 2002

SO BE FREE #7

March 2002

Hopland Research and Extension Center


Location:

The Hopland Research and Extension Center is the University of California's principal field research facility for agriculture and natural resources in the North Coast region. Located 40 miles inland from the Pacific Ocean in the rugged Mayacmas Mountains of southeastern Mendocino County, the 5,358 acre center is topographically and biologically diverse. Elevations range from 500 to 3,000 feet. The soils are predominately fractured sandstones and shales or glaucophane schist with related metamorphic rocks of the Franciscan Formation. Serpentine outcrops are common. The principal vegetation types include annual grassland, mixed oak woodland, hardwood forest, and chaparral, which support 675 vascular plant species, 56 mosses, 5 liverworts, and 60 lichen species.

Typical of the interior North Coast Ranges, the natural vegetation reflects a mediterranean climate of hot dry summers and cool wet winters, with an average annual rainfall of 38 in. Oaks and other hardwoods are common overstory species of the lower elevation woodlands and include blue oak (Quercus douglasii), black oak (Q. kelloggii), valley oak (Q. lobata), Oregon oak (Q. garryana), coast live oak (Q. agrifolia), Shreve oak (Q. parvula var. shrevei), California bay (Umbellularia californica), Pacific madrone (Arbutus menziesii), and California buckeye (Aesculus californicus). Grasslands and the understory of open oak woodland and savanna are dominated by non-native annual grasses such as slender wild oat (Avena barbata), big quaking grass (Briza maxima), hedgehog dogtail (Cynosurus echinatus), and barbed goatgrass (Aegilops triuncialis). Chaparral scrub consisting of chamise (Adenostoma fasciculatum), Arctostaphylos spp., Ceanothus spp., and Quercus spp., along with patches of closed cone pine (Pinus attenuata) are common above 2,200 feet. Douglas fir (Pseudotsuga menziesii), California nutmeg (Torreya californica), and canyon live oak (Quercus chrysolepis) form dense shaded canopies on steep north and east facing slopes. Numerous seasonal creeks, sag ponds, vernal pools and springs provide a diversity of wetland habitats and plant communities.

Prior to the University's purchase of the property in 1951 the area was used as a sheep range. Today, a research flock is still maintained and ranges over 2/3 of the Center. Livestock are excluded from approximately 1,100 acres in designated "biological areas," research pastures, and steep, wooded terrain outside of fenced pasture boundaries.

Schedule

On Saturday 3/23 we gathered at the Hopland Research and Extension. Local bryologists Dave Toren and Kerry Heise gave an orientation lecture about the region.

On Sunday we took an all day field trip to the Mendocino coast to see the redwood forest, deep canyons, and the famous Mendocino pygmy forest -- which grows on old, raised, beach-terrace podsols with underlying hardpan on a series of Pleistocene marine terraces. Each terrace is about 100,000 years older than the next below. The evolution of soils on this "ecological staircase", has provided a foundation for studies of vegetational succession over a period of 500,000 years, and biotic responses to a steep gradient of soil fertility, which supports normal coastal vegetation on lower younger terraces, but becomes impoverished in nutrients to produce a climax pygmy vegetation on the uppermost terrace.

On Monday Dave Toren led a trip to the drier interior habitats of Lake County. Stops included Anderson Springs, a former hot spring resort with sulfur hot springs where you can find Ditrichum ambiguum, Ditrichum schimperi, Pohlia nutans, and the rare Mielichhoferia elongata. The hepatics Cephaloziella turneri and Jungermannia sp. are also found there.

We made a few stops along Highway 175 in the Cobb Mountain area to see the aquatics Hygrohypnum bestii and Platyhypnidium riparioides. We also stopped in the Boggs Mountain State Forest to see Andreaea heinemannii and the rare Grimmia mariniana growing on volcanic boulders. On the way back to Hopland, we stopped at Manning Creek about 4 miles west of Lakeport on Highway 175. This is an area of rolling hills, oak woodland with California Juniper, chaparral, a creek, and rock outcrops, together supporting a very rich bryophyte flora. Species of Grimmiaceae and Pottiaceae are numerous here and Encalypta vulgaris, Entosthodon californicus, and Bartramia stricta should be found. Didymodon norrisii is also found in abundance here (with sporophytes!) along with such rarities as Bryoerythrophyllum columbianum and Pseudocrossidium obtusulum.

During the evenings we had slide shows about bryophytes and the current research efforts of the participants. On Tuesday we explored the HREC itself for the morning, departing after lunch.