Aliens Among Us

How did the Tasmanian Blue Gum Eucalyptus, a tree from Australia, come to dominate the Bay area landscape? The story begins in the 19th century, soon after the gold rush, when thousands of settlers needed wood to build and fuel the city. At that time, settlers were logging oaks and redwood at an alarming rate. Eucalyptus was known to be a fast-growing hardwood, and its ability to soak up water could reduce swampy land. San Francisco, fast- growing and surrounded by muddy tidal flats, embraced the exotic species.

Central and Southern California, naturally grassy with few trees, followed suit. The state legislature passed the California Tree Culture Act in 1868, paying landowners $1 per tree to plant and nurture trees for a minimum of 4 years. Over the next 40 years Californians, encouraged by the government and by promoters, planted eucalyptus seedlings by the thousands. The tree would provide shade, windbreaks, railroad ties, antiseptics, fuel, fencing, and more. As the tree soaked up water and created tillable land, it also diminished a breeding ground for mosquitos and helped reduce malaria.

Some notable examples:

  • Leland Stanford planted 700 trees in a mile-long row at Stanford University as a promenade called Governor’s Row.
  • The US army planted eucalyptus at the Presidio as a windbreak and as a way of distinguishing the base from surrounding areas.
  • Adolf Sutro planted a forest of eucalyptus on Mt. Parnassus (now called Mt. Sutro) for a public pleasure garden and to take advantage of a tax break for forested areas.
  • Central Pacific Railroad planted 1 million eucalyptus in the San Joaquin Valley for railroad ties, poles, and posts.
  • Writer Jack London planted over 40,000 seedlings on his ranch in Sonoma, hoping to sell the wood for profit in a few years.
  • Frank Havens, a developer, planted 8 million trees in a 14 mile strip from Berkeley to Oakland.
  • Abbot Kinney, state forester, promoted the tree and distributed free seeds across the state.

Eucalyptus trees flourished in California’s mild climate, but the harvested young wood proved a disappointment. Prone to twisting, cracking and hardening, the wood was unsuitable for furniture or railroad needs. When oil replaced wood as a source of fuel, the demand for eucalyptus declined. The eucalyptus bubble burst, and the trees were left for shade, shelter and bird habitat.

Changing Attitudes:

Today environmentalists admit the invasive nature of the eucalyptus tree and its hazards: its instability and its flammability. Yet they recognize that the tree has become home to many birds, animals and the endangered monarch butterfly. The park service manages the eucalyptus forests to reduce the hazards but preserve the trees by removing tree limbs, surface fuel, thinning trees and removing stumps.


Governors Row, Stanford

Inspiration Points

Happy Isles in Yosemite was the site of a massive rock slide in 1996. Today you can see the remains of the rockfall in boulders, broken trees, and disrupted landscape. One trunk, still standing but broken and hollowed, reminded me of “Spire”, Andy Goldsworthy’s artwork in San Francisco’s Presidio.

Spire is a carefully constructed tapered column of cypress logs, held together in such a way as to look entirely natural and effortless. The column rises 90 feet above the floor of the Presidio, near an aptly chosen location, Inspiration Point. It is an art work typical of Andy Goldsworthy.

Goldsworthy, a British artist who oversaw this project in 2008, is known for creating works of natural materials, in natural settings, and subject to the changes that occur in the outdoors. His creations fit into their settings, yet surprise us with their unusual order or patterns. The artist’s hand is invisible but implied. So, for example, Goldsworthy’s Wood Line (2011), also in the Presidio, is a series of Eucalyptus trunks arranged in a curved line through the Eucalyptus forest. The Eucalypus trunks are expected; the orderly curves are not.

Conceiving of Spire and constructing Spire, Goldsworthy faced challenges. The logs were chosen from an inventory of fallen trees left from the culling of the forest. Their trunks were massive, weighing as much as 17,000 lbs. each. Their trunks were not always straight, and had to be bent to fit the tapering vision. The construction had to be strong but unseen, managed with cranes and cherry pickers.

This “Spire” takes its place among San Francisco’s other spires. The church spire of Saint Ignatius, and the Transamerica Pyramid once dominated the landscape, but now disappear among other skyscrapers. Likewise, “Spire” dominates its setting today, but in time will disappear among the younger and replanted trees.

Hiking in Yosemite High Country

Last week we hiked and backpacked in Yosemite with an able and informative guide, Kari. In 3 days we hiked 24 miles along the Pohono, Panorama, and the John Muir Trails, and camped for 2 nights. Our route started at the Tunnel View trailhead, with a steep uphill climb over a rocky (Kari called it “technical”) and unshaded path. My first impression was regret that I had committed myself to 3 days of this exercise. It was hard to appreciate the scenery as I stepped gingerly over loose rocks and dry sandy soil.

Our first break was a viewpoint at Mile 1.3, Inspiration Point; and it is aptly named. By this time we had climbed to 5,390 elevation, and had earned a view of Yosemite Valley and Bridalveil Fall. John Muir took Teddy Roosevelt to Inspiration Point in 1903 when they explored Yosemite together.

Our next two days consisted of one breathtaking view after another breath-taking hike.

In time, I came to enjoy the exercise, and the atmosphere. Kari was a wealth of knowledge about the names and features of flowers, birds, trees, and geologic forms. We passed by Stanford Point, Crocker Point, Dewey Point, Taft Point, Glacier Point and others.

The trees provided welcome shade along our route. We hiked through white fir, red fir, sugar pine, lodgepole pine, ponderosa pine and others. The ponderosa pine has long needles, in bundles of 3, with a jigsaw puzzle bark. At higher elevations, 7,000 feet, it yields to Jeffrey pine, with similar features but a fragrant, vanilla-smelling bark. The lodgepole pine twists in the wind and often twists further as it declines and dies. You can see these unique curves in the grain in one of the lodgepole pine trunks at our first campsite.

Purple, white and yellow wildflowers abound in Yosemite this time of year. But a highlight was certainly the snow flower. This striking stalk-like plant shoots straight up, with an unapologetic bright red coloring. It contrasts sharply with the forest floor, seemingly out of place. Kari explained that it is named for its tendency to poke noticeably out of the snow, early in the spring. Lacking chlorophyll, it is a parasite, feeding off the fungi of tree roots. It blooms from May to July in Yosemite, part of the heath family.

When we reached Sentinel Dome, Kari asked us if we wanted to add 1 mile to our itinerary and climb the Dome for another excellent view. I surprised myself by agreeing. Sentinel Dome offers 360 degree view of the Valley, Half Dome, and points beyond. The skeletal Jeffrey Pine tree on top was once photographed by Ansel Adams (1940) but has since died.

By our third day of hiking, I was stronger and more ambitious. I had acquired a newfound respect for the grandeur of Yosemite and a better understanding of experiencing the park out of the crowded Valley.

Bird Life on Alcatraz

In 1769 Spanish explorers mapped a small island at the entrance to San Francisco Bay, and called it Alcatraces after the abundant seabirds sighted there. By 1850, the island sported a defensive fortress, and the Bay’s first lighthouse. As the US military arrived and settled, the birds left, sensing they were no longer welcome. It wasn’t until 1972 when the island was again uninhabited, that the birds began to return, first the seagulls and then other species. They began nesting in the trees, thickets, natural rock crevices and the man-made concrete structures.

Recently I visited Alcatraz for a tour of bird-nesting areas with park ranger Tori Seher. She identified 9 bird species that nest on Alcatraz annually: gulls (California and Western), herons (Great Blue and Black-Crowned), pigeon guillemots, cormorants (Brandt’s and Pelagic), snowy egrets, and black oystercatchers. These populations are significant in that they are large (over 1000 pairs make up the 2nd largest Western Gull colony on the West Coast), and unique (pigeon guillemot have only one other small nesting area near Berkeley). The rangers keep a census of bird sites and populations from March to September, the primary nesting season.

Alcatraz has no natural source of fresh water, and no natural predators. Ravens, however, have taken up residence on Alcatraz and have been known to eat black- crowned night heron eggs. To control the raven population, the park service regularly oils the raven eggs to prevent them from hatching.

Sensitive nesting sites are off-limits to visitors to ensure a refuge for the birds. We viewed some of the species through binoculars and Tori’s telescope, and saw the cormorants through frosted windows in the New Industries Building. Fortunately, we were able to get very close to the egrets. Tori also delighted us with a story about a lone northern gannet, a bird from the Atlantic Ocean, sighted recently and repeatedly at Alcatraz. This wandering bird may have flown over the Arctic Circle but has arrived in California only to look for a mate fruitlessly.

Today Alcatraz struggles to balance the needs of their various seabird populations with that of the historical structures on the island. Some of the challenges include the long term effects of a large Western gull population on the island, the interruption of regular maintenance on the structures, the corrosive effects of bird excrement, and the ongoing relationships among the bird species within the ecosystem.