History of Eucalyptus Trees in California
Eucalyptus trees can be seen everywhere across California. Hundreds are planted on a grove at the highly acclaimed Stanford University. These trees are not native to California, though. In the 1850s, California was in need of lumber for housing during the Gold Rush (Staff). Ralph Hosmer, an Australian native, thought that the fast growing Eucalyptus tree could fix the lumber issue (USNPS). Hosmer brought over hundreds of Eucalyptus trees, mainly the blue gum Eucalyptus, Eucalyptus globulus, to California over the late 1800s (Staff). Since then, Eucalyptus trees of many species can be seen all over California, and especially the Bay Area. All these trees have their issues though.
Negative Effects of Eucalyptus
Eucalyptus trees have become an increasing problem as droughts have rung out across California. Eucalyptus trees are extremely flammable, with their oils often leading to combustion of the trees when set on fire. This creates a massive fire hazard across the state, as dry years lead to more fires. Different species of Eucalyptus trees often have different levels of flammability. In particular, Eucalyptus globulus are known as one of the most flammable Eucalyptus trees. With over five hundred E. globulus planted in San Francisco, based on the SF Street Tree List, the flammability of Eucalyptus trees is a huge issue for Bay Area residents. Eucalyptus trees also cause huge problems during dry years as, like other trees, their roots get looser in dry soil. This leads to a high amount of Eucalyptus trees falling over during high wind storms, which have been increasing due to climate change. In January, a Eucalyptus tree fell down near Golden Gate Park, crashing down on 11 cars (Ramos). Luckily, no one was seriously hurt, but Eucalyptus trees falling over is a constant problem in the Bay Area. During January of 2023, a eucalyptus tree fell over onto the Burlingame CalTrain tracks (CalTrain). This shut down the tracks for over 12 hours (CalTrain). The Burlingame CalTrain station is known for being surrounded by Eucalyptus trees, which often need to be trimmed. With the rise of falling Eucalyptus trees in the Bay Area in recent years, it is an issue CalTrain is extremely concerned about.
When it comes to lumber, Eucalyptus trees are not the best tree species in the slightest. Eucalyptus trees are often hard to harvest after being cut, as they are known for splitting when dry. This causes a danger risk when cutting with a chainsaw or heavy machinery. This splitting also makes the eucalyptus useless for lumber, as the wood becomes brittle, barely usable. Removal of eucalyptus trees is often a challenge as well, as the stumps of cut eucalyptus trees are known for growing roots out of them. These roots grow into new eucalyptus trees, which are usually weaker and fall more easily. The last thing that eucalyptus trees do that negatively affects the environment of San Francisco is bark shedding. The bark of Eucalyptus trees often sheds onto roads in SF. This can cause the urban roads of SF to be closed down due to street cleaning.
Eucalyptus Trees in San Francisco
Twice every week, the San Francisco Public Works department undertakes the collection of a list of all of the Street Trees in the entire city of San Francisco. The dataset does not account for trees inside of Golden Gate Park but details all the trees in public streets. Over the years, the Public Works department has detailed almost four thousand eucalyptus trees all over San Francisco streets. With 23 different species of Eucalyptus calling San Francisco their home, the tree is an integral part of the city.
This map shows the location of all 3574 Eucalyptus Trees in San Francisco that were located on the SF Street Tree List by the San Francisco Public Works Office. Note that no trees were located in Golden Gate Park, Presidio National Park, Lincoln Park, and Treasure Island. The San Francisco Public Works Office did not collect any data from the San Francisco’s city parks or any data from outside mainland San Francisco.
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## Eucalyptus camaldulensis :: River Red Gum
## 87
## Eucalyptus cinerea :: Ash-colored Eucalyptus
## 11
## Eucalyptus citriodora :: Lemon scented eucalyptus
## 182
## Eucalyptus globulus :: Blue Gum
## 514
## Eucalyptus gunnii :: Cider Gum
## 2
## Eucalyptus lehmanni :: Bushy Yate
## 94
## Eucalyptus leucoxylon mac 'Rosea' :: Yellow Gum
## 45
## Eucalyptus longifolia :: Woollybutt
## 3
## Eucalyptus macarthuri :: Camden Wollybutt
## 3
## Eucalyptus melliodora :: Yellow Box
## 13
## Eucalyptus microtheca :: Flooded Box: Coolibah
## 15
## Eucalyptus nicholii :: Nichol's Willow-Leafed Peppermint
## 198
## Eucalyptus odorata :: Peppermint Box
## 2
## Eucalyptus polyanthemos :: Silver Dollar Eucalyptus
## 1011
## Eucalyptus pulverulenta :: Silver Mountain Gum Tree
## 23
## Eucalyptus robusta :: Swamp mahogany
## 22
## Eucalyptus rudis :: Swamp Gum: Flooded Gum
## 12
## Eucalyptus saligna :: Sidney Blue Gum
## 5
## Eucalyptus sideroxylon :: Red Ironbark
## 695
## Eucalyptus simmondsi :: Simmond's Peppermint
## 2
## Eucalyptus Spp :: Eucalyptus
## 518
## Eucalyptus torquata :: Coral Gum
## 1
## Eucalyptus viminalis :: Manna Gum
## 26Here is a table of all 23 species of Eucalyptus in San Francisco. It is very interesting to see the dominance that the blue, coral and silver gum species has in San Francisco. Over half of the eucalyptus trees are from those 3 species. If you include the red ironbark species into that total, over 70 percent of all Eucalyptus trees in San Francisco are of only 4 Eucalyptus species.
Fires Caused by Trees
This map shows the location of all 3826 Tree Related Fires in San Francisco that were collected on the SF Fire Data by the City of San Francisco.
What Neighborhoods are Effected
The best way to show which communities are most affected by the fire risk Eucalyptus Trees bring to San Francisco is by a heat map showing where the most Eucalyptus Trees are in San Francisco,compared to a heat map of Tree Related Fires in San Francisco.
Most Eucalyptus Populated Neighborhoods
This heat map shows the frequency of Eucalyptus Trees in the 117 San Francisco districts.
The neighborhood with the most Eucalyptus Trees is Bayview, with a staggering 460 trees. This is almost 300 more trees than the second most Eucalyptus populated neighborhood, the St. Francis Wood with 176 trees. India Basin comes in third place, with 139 Eucalyptus trees.