It is impossible to imagine Sonoma County without its majestic redwood trees and stunning oaks. Besides giving shape and definition to our hills, valleys, ridges and rural scenery, their likenesses are etched on our county seal, town logos, highway markers, school monuments and countless commercial labels. We live in a “redwood empire” where the original people here centered their culture around acorns.
Trees are at the pinnacle of our natural world, and are living expressions of healthiness, vibrancy and biological dynamism. In times such as ours where droughts, hurricanes, wildfires and a global pandemic fill our thoughts with dread and unease we can look to our towering redwoods and muscular oaks for reassurances, knowing that the oldest redwoods are nearly 2,000 years old and the oldest of our heritage Valley Oaks may have trunks as wide as a driveway.
The coastal redwoods (Sequoia sempervirens) and our dominant Valley Oak (Quercus lobata) are two of 58,497 tree species worldwide, according to Botanic Gardens Conservation International (BGCI). While many thousands of our oaks and redwoods (and firs) have been destroyed by recent wildfires, there is an alarming and expanding threat to thousands of other tree species. According to BGCI’s just-released Global Tree Assessment, 30% of all tree species are currently threatened with extinction and 142 species have been recently recorded as extinct. (There are 1,424 tree species in the United States and 342 are listed as endangered, or 24%.)
The main threats to these tree species are the same ones recorded here in Sonoma County since the arrival of Europeans and Russians just two centuries ago. “These threats include forest clearance and other forms of habitat loss, direct exploitation for timber and other products and the spread of invasive pests and diseases. Climate change is also having a clearly measurable impact,” the report states.
Less than one-fourth of the original coastal redwood forest remains standing today and the coastal redwood habitat has now shrunk to a narrow ribbon along California’s coastal ridges from Big Sur to the Oregon border. The native people here did not cut down redwoods, but made use of fallen trees, bark and limbs for shelters and dug-out canoes. The population boom during the Gold Rush of 1849 put an explosive demand on lumber and many stands of redwoods were clear-cut and shipped worldwide.
Besides being the tallest living things on earth, redwoods possess many other amazing qualities. They are among the fastest growing conifer species and can generate from seeds, cuttings and sprouts. They are extremely fire-resistant and they provide a diverse habitat for other flora and fauna species, including several endangered ones. Redwoods can make their own rain by capturing fog and distilling it into drops of water.
Sonoma County has many oak species including the Valley Oak, Coast Live Oak, Blue Oak, and California Black Oak. Where we now see valley floors and sloping hills full of vineyards, pastures or open grasslands, these lands were once dense oak groves and forests. A State of California report, “Oaks 2040,” estimates that 750,000 acres of oak woodlands are seriously threatened by an expanding human population. Also, the uncontrolled spread of Sudden Oak Death (SOD) continues to annually kill thousands of oaks in our region, since its discovery here in 1999. The SOD pathogen has spread to other tree species and there are fears it may leap into the redwoods.
We think of trees and forests as permanent fixtures of our natural world. It is hard to grasp the extinction warnings of the Global Tree Assessment report. We’ve heard about the clear-cutting of the Amazon jungles and the slow spread of the Sahara Desert.
We don’t need another emergency, pandemic or natural disaster to add to our lists. But if there is something we can do differently to better protect our redwoods, oaks and other trees, we’d want to know about it and take action, wouldn’t we? (Find the report at www.bgci.org.)