Doug's Mountain Journal
A Chronicle of Natural History on San Bruno Mountain
Doug Allshouse has been writing his seasonal Mountain Journal for many years. We are very pleased to share his reflections on the natural history of the Mountain. Together with David Nelson, he wrote San Bruno Mountain: A Guide to the Flora and Fauna. The book was published by Heyday Books in November 2022 and can be purchased here.
Winter 2025
Thank goodness autumn is over, and a crisp and wet winter is ready to make me happy. This is the season of renewal when all our sleeping perennials come to life and early annuals poke out of the ground. Christmas morning, 2024 produced a spectacular, fiery sunrise that really caught my eye. As the sun rose higher the show evolved into patches of hot-pink clouds with a lonely crescent moon dancing over the summit. It was truly a magnificent Christmas gift. I recalled that Christmas 2020 produced a rare double rainbow next to the Mt Sutro tower. Christmas appears to be a good day for sunrises.
Precipitation was light until November and December combined for 10.45 inches of rain, but January fell asleep—as it sometimes does—by becoming the third driest January (0.52) in ten years. I was wildly surprised to see the drainage ditches on the Old Guadalupe Trail and the headwaters of Colma Creek above the Day Camp brimming with standing and flowing water after so little rain. It is a testament to how resilient and high the water table remains to be after the last three rainy seasons, almost eighty-eight inches of rain! Two respectable storm systems plus fifteen additional days made February the wettest month with 5.48 inches. March came in like a lion with a mild storm system over five days that produced a little precipitation and was quite windy. Then in the middle of the month another series of storms brought March to 1.76 inches and bumped the seasonal precipitation to 19.49 inches. That is half an inch shy of an average year of 20-24 inches.
One good deed deserves another.
In my autumn edition I was praising the Go Native crew that transformed portions of the Bog Trail by removing massive amounts of cotoneaster, English ivy, gorse, small eucalyptus, English holly, and cypress trees. Suddenly there were open spaces that used to be clogged by the presence of these invasive species. The ensuing neglect that followed the volunteer-based restoration work in the bog twenty years ago bothered me for many years. The likelihood of Go Native’s excellent work going to waste would be a travesty. I was so impressed with their work that I decided to supplement it with some volunteer work of my own. An area between the Bog and the Old Guadalupe trails contained some larger eucalyptus and Monterey cypress trees that had English ivy climbing up the trunks. They needed a haircut, so I began cutting the ivy at the base and pulling the vines off the trunks. Over a three-week period, I stripped English ivy off twenty-nine tree trunks and now the maintenance work kicks in. A quick inventory found fifteen toyons thriving in this new environment, plus I freed some sword fern at the base of a trunk, and two leather ferns clinging to the trunks of two eucalyptus trees that were smothered by the ivy.
Removing English ivy from eucalyptus trees is fairly easy since the bark is smooth, and the trunk is generally not branched close to the ground. Monterey cypress, Sitka willow and coast live oak demand much more labor and determination. They are branched near the base and their bark is thick and textured. The vines really cling to them. (Branches allow vines to travel somewhat horizontally which negates the force of gravity while also allowing the vine to cascade downward to the ground) If the vines are young and no more than a half inch in diameter it is much easier to grasp the vine and pull them away from the bark. A few tugs should break their hold and allow one to cut the vine at the base and strip them off the tree. The older vines that are an inch or more generally pose a problem because they really grab onto the trunk. I cut the big vines and let them hang. It can take 6 months to more than a year for the vines to die. Eventually they become susceptible to aggressive tugs and fall away from the tree. I remove ivy, not because I feel sorry for the eucalyptus trees, but because I absolutely hate English ivy and how it destroys ecosystems. In addition to smothering everything on the ground, this ivy changes personality when it manages to get vertical by climbing. The leaves change shape, the stems thicken and grow woody hairs, and they flower and produce fruits, which entices birds to eat them and move the seeds around in their poop.
I have also been working on the oaks and willows along the Day Camp Road and at the Day Camp.
I have mentioned my excitement about the proliferation of our native red elderberry bushes in Fog Forest and how they thrive under the canopy, but lately another problem and project has surfaced. If I want them to continue to thrive, I must remove the Cape ivy that has begun to crawl up the stems. Cape ivy used to be known as German ivy, but it was neither German nor an ivy. It is native to the Cape region of South Africa, which has bestowed the Mountain with several other bad actors: sour grass/Bermuda buttercup (Oxalis), panic veldt grass (Ehrharta), and Cape weed (Arctotheca). Cape Ivy is a vegetative plant with soft, thin green stems and its ability to climb is achieved by twining or wrapping around the stems of the elderberry. When it is seen climbing up a tree trunk rest assured that it is actually climbing up the English ivy that got there first. The ivy interferes with photosynthesis by covering the elderberry leaves, hides the flowers and the fruit, and adds weight to fragile stems thereby causing damage. I am constantly pulling the vines off the bushes in a never-ending battle, but it’s worth the effort.
It is late winter, and the days are getting noticeably longer, which is triggering arroyo willow flowers to emerge. Their delicate catkins paint a soft yellow hue across the landscape. These willows, thriving in moist areas, bring a subtle but significant beauty to the mountain. Their flowers provide vital pollen to early emerging bees and other insects, playing a crucial role in the ecosystem's chain of life. Willows grow very quickly and sprout new branches called wands that were used for making boats, baskets, and furniture by Native Americans. The bark contains salicylic acid, the active ingredient in aspirin, and the bark was chewed to relieve pain and reduce swelling. Its genus, Salix, is Latin for willow and most likely was the root for salicylic. Sausalito means little willow in Spanish.
Finally, I heard some winter music.
It’s been rather quiet this winter in Fog Forest and the Bog until the Sunday before the Spring Equinox. It began with a couple minutes of high-pitched yelping from a few coyotes at the western edge of the Bog. I always enjoy hearing those sounds. Walking down the Day Camp Road I was serenaded by a few Robins. As I crossed the upper Colma Creek bridge I heard an Orange-crowned Warbler singing in the creek dogwoods. The finale involved a Song Sparrow’s quirky melody with some percussion from a Downy Woodpecker on a tree. Migration and mating season has officially begun!
It is exhilarating to see the willow and elderberry leaves and flowers springing to life, and the cow parsnip bolting out of the ground. I’m anticipating what lies ahead for this spring. Can’t wait!!
See you on the Mountain…
Doug