During this past winter of 2022-2023, I ventured outside only for CNPS East Bay Chapter restoration crew work (a.k.a. broom bashes or Genista rips). When East Bay parks reopened after the COVID-19 lockdown, Huckleberry and Sibley parks both benefited from new volunteers on our restoration crews. But as Thanksgiving rains merged with holiday storms, followed by January wind events and rain again for the Chinese New Year parade, I stayed in to watch local newscasts of road crews sawing up fallen eucalypts and cedars. Despite the sadness of storm injuries and wrecked homes, I grew curious to see how nearby parks and streets fared in comparison to the mudslides and tree crashes on my TV set.
By luck of the draw, our chapter did not have to cancel any restoration crews at Sibley and Huckleberry parks. Only light rain or mist fell on the designated volunteer dates. November led to flowing water in Round Top Creek in Sibley Volcanic Regional Preserve, which had been completely dry at the start of October. By December, we switched our route away from the East Bay Skyline National Recreation Trail to the paved fire road because of muddy soil and plentiful trailside water. Compared to French broom’s grip in the near-cement clay of October, that plant almost slid out of the mud when we pulled it in the mist, even without the use of tools. (Best to call it Genista, from its Latin name Genista monspessulana—it doesn’t grow in much of France.)
Similarly at Huckleberry Botanic Regional Preserve, we did not venture too far from the parking lot, and soft soil made for easy removal of poison hemlock (Conium maculatum), Italian thistle (Carduus pycnocephalus), and veldt grass (Ehrharta erecta). Despite a mudslide closure on the East Bay MUD section of the Skyline Trail, Skyline Gardens volunteers still ventured out from the Tilden Park entrance.
Grasses, forbs, and most maritime chaparral plants survived the winter storms with little fuss, bending to the wind and rain. However, some trees fared not so well, and trees near human structures faced even more obstacles to remain upright.
The shrubby growth habit of arroyo willows (Salix lasiolepis) allowed them to bend easily, sacrificing some larger branches but resprouting vigorously in the damp spring. A taller, older red willow (Salix laevigata) at the foot of Albany Hill nearly broke in two. However, even the broken branches of the red willow resprouted, and the reddish twigs on the new growth made sense of its common name.
Urban trees seemed to suffer the most, whether they were in landscaped parks, in front yards, or along streets. There were so many broken branches on curbsides by March that I was able to collect leafy twigs from the fallen pieces for sketching practice. Atlantic and deodar cedars (Cedrus atlantica and C. deodara) dropped branches on many Oakland and Berkeley streets. Some coast live oaks (Quercus agrifolia) also crashed to the ground along streets but fared better in open-space parks, with some now resprouting along grounded trunks. Monterey cypress (Hesperocyparis macrocarpa) often blew over in the winter storms. Along the Berkeley Marina roads, there are bright yellow piles of chipped Monterey cypress alongside surviving cypresses, most of which show recent branch cutting.
Tasmanian blue gum (Eucalyptus globulus) crashed to the ground in the greatest numbers along Skyline Blvd. and other hilly streets. Height alone did not predict which eucalypts toppled over, as many shorter blue gums fell into the street along with some piles of muddy soil. Branches of shorter red gum (E. camalduensis) and forest red gum (E. tereticornis) appeared on flatland street curbs. To further confuse tree height as a storm risk, the shorter, more invasive Acacia species (especially Acacia melanoxylon, but also A. longifolia and A. dealbata) often fell onto Oakland streets alongside Tasmanian blue gums with no obvious survival advantage to either tree.
Monterey pines (Pinus radiata) also fared poorly in the storms, with some older trees causing serious property damage as they fell in the wind. I viewed these fallen pines with some irony. At the turn of the last century, many real estate and lumber speculators planted Tasmanian blue gum and Monterey pines in Oakland where loggers had clearcut redwoods, and in Berkeley and Oakland to “beautify” remaining coastal prairie stands. We’re all living with the consequences of their bad bets in tree planting, which number far too many to list here. For more detail, read any of Jerry Kent’s thoroughly researched articles on tree plantings in Oakland and Berkeley, available on the Claremont Canyon Conservancy’s Publications page.
The human, horticultural planting factor loads risks onto the hills for both rainy and fire seasons. Seasonal burns would likely reduce fire risk most effectively, but homeowners understandably object to the risk of fire jumping control lines and reducing air quality. Other “vegetation management” methods cascade into more unintended consequences. As Betsey Landis discusses in “How CNPS Developed a Policy on Native Plants and Fire Safety”:
Other fuel management methods include mastication, crushing, and building fuel breaks, all of which destroy the intricate root matrix native plant communities create to knit the fragile watersheds together. In heavy rainfalls, mudslides are inevitable. Loss of healthy topsoil leads to non-native shallow-rooted grasslands, which in turn lead to more frequent early season wildfires.
Betsey’s article appears in Fremontia Vol. 38, Nos. 2 and 3, Special Issue: Native Plants and Fire Safety. I strongly recommend the rest of the article, especially the list on page 8 of “Some Plants to Avoid When Landscaping in Fire-Prone Areas” and photos on page 10 of erosion damage after total vegetation removal.
Drawing ©Janet Gawthrop.
Finally, at the Morcom Rose Garden in Oakland, one of several dozen coast redwoods (Sequoia sempervirens) fell across the rose beds and garden paths during a winter storm. I picked a portion of a branch to practice drawing its needles, arranged so differently from cedars. When I returned in May, most of the tree had vanished. However, the redwood stump and root ball had been replaced back where it fell, and now green sprouts are climbing above that remnant stump. I am glad East Bay residents like coast redwoods; if they were disliked as weeds, we would have quite a time trying to get rid of them.
—Janet Gawthrop, Field Trips Committee Chair, and Sibley Volcanic Regional Preserve and Huckleberry Botanic Regional Preserve volunteer restoration crew coordinator, CNPS East Bay Chapter
July 2023
