Sonoma County Forests, Part Two: Changing woodlands

Arthur Dawson, THE PRESS DEMOCRAT

Editor’s Note: This is part two of a series about the indigenous forests that blanket Sonoma County — their past, present and threats to their future.This is the second in a series of three stories about Sonoma County forests that will be published in Sonoma Outdoors.

Part 1: The history of Sonoma County forests, January

Part 2: Where our forests stand now, February

Part 3: Our forests’ future, March

The 2017 North Coast Forest Conservation Conference, “Growing Resilience,” will take place June 7-9 at Santa Rosa Junior College’s Shone Farm, 7450 Steve Olson Lane, Forestville.

More information: Sonoma County Forest Conservation Working Group, sonomaforests.org

For the latest on the Sonoma County Vegetation map, visit sonomavegmap.org

Our forests “are undergoing a sea change,” observes Mark Tukman, founder of Tukman Geospatial, who is spearheading the Sonoma County Agricultural Preservation and Open Space District’s development of a fine-scale vegetation map.

“I’ve spent over a year looking at aerial photos and coordinating field teams. Many of our oak woodlands are disappearing rapidly, transitioning to Douglas fir and California bay,” he said.

In many places this is visible at ground level — dead manzanitas scattered beneath oaks dying in the shade of Douglas firs — a century of change visible in a glance. Of course, oaks and firs represent just a few of our native trees. Sonoma County’s wide range of geology, soils, landforms and climate has been described as “where Alaska meets Mexico.” With 10 species of oaks and 19 conifers, our forests reflect this diversity.

Close up, they can seem infinitely complex. But if you pull back, larger patterns emerge. Moving west to east, conifers grow in parallel bands — Bishop pine along the cool coast, then redwoods, and finally Douglas fir reaching warmer areas far inland. Interspersed are woodlands of oak, bay, madrone and other hardwoods. There are no hard boundaries between any of these types — in fact mixed conifer-hardwood forests are more common than either alone.

By the early 20th century, forested lands had seen severe impacts. Logged-off tracts of redwood and Douglas fir were now brushy and crowded with young trees. Oak and madrone woodlands, leveled for firewood, had become grassland. Settlements replaced oak savannahs. By all indications, there were far less trees 100 years ago than today.

Read more at: The state of Sonoma County’s forests | The Press Democrat