microclimate

Working in California is drastically different than working in the eastern U.S., is so many ways.

I was reminded of one of those ways on the drive north tonight. As I left San Francisco about 7:00 pm, a full moon was readily visible through thin, broken clouds. Just 45 minutes north, in Petaluma, I began to encounter cells of light showers. North of Santa Rosa, it was raining more often than not.

North of Ukiah, Rt.101 begins to climb in elevation. Not a lot, but between Willets and a little north of Laytonville, the highway is at 1,500 to 1,800 feet. Tonight, that was enough for the rain to begin to turn to snow. Not much, none sticking on the road, but snow was readily visible in the bordering vegetation. Caltrans plows waited patiently in a few places in case it became heavier. Before intersections, signs warned of winter conditions on the higher elevation roads crossing east over the inner coast ranges.

North of Laytonville Rt. 101 drops quickly, and here there was first light rain, then patchy fog. The rest of the way north from here, microclimate was the rule. Every valley, every ridge seemed different than the one before. Rain started and stopped and started again. Fog hung in some valleys but not others.

This microclimate profoundly affects restoration planning. I've worked on sites where a fog gap, a low spot in the coastal mountains, has allowed coastal terrace prairie dominated by California oatgrass to develop and persist in places 10 miles inland that ordinarily would support a valley needlegrass association. That's just one example. Here, microclimate is the rule. Different parts of the same preserve can have different enough weather to affect what grows.