Recently, I wrote about the need for careful management of forest and bush areas in order to avoid fires.

In 2011, the Santa Barbara Independent had an excellent article, ‘How the Eucalyptus Came to California’. As the subtitle says, it is a cautionary tale.

Excerpts follow, purple emphases mine.

The eucalyptus Tree is not native to California. It comes from Australia, and, for decades, generated a lot of business. It was easy to grow:

The story of how the eucalyptus came to be embedded in much of California’s scenery is a great example of lack of forethought when introducing a plant to a new area.

Australian roots: In 1770, eucalyptus specimens made their way to Europe for the first time. On his first Pacific Ocean trip, Captain James Cook explored part of the Australian coast. Botanists onboard catalogued and collected several different species along the way, taking them back to London. European botanists gave the trees the name “eucalyptus” because of how the flowers are in hard, protective cup-like structures: The Greek root “eu” means “well” and “calyptos” means “covered.”

Soon, interest in the eucalyptus swelled in Europe. In the early 1800s, wealthy merchants and aristocrats were excited about rare or “exotic” plants and, together with people in the plant business, made cultivating eucalyptus trees popular. Horticulturists also wanted to better study such novelties, to understand them scientifically and see what their potential economic value might be. And of course, the new European settlers in Australia were eager to make some money selling the abundant eucalyptus. Promoters touted the trees as not only aesthetically pleasing, but as capable of satisfying many practical needs. The eucalyptus quickly spread in Europe.

Eucalyptus is a very large genus that consists of over 600 species, which natively live in Australia, Tasmania, and some surrounding islands, in a range of soil conditions and temperatures (though prolonged frost is usually detrimental). They do very well in Australia; 80 percent of Australia’s open forests are eucalyptus trees. With some aromatic species majestically soaring over 300 feet tall, as a hardwood tree their height is second only to California’s coastal sequoias. It’s easy to see their appeal.

On an economic level, many early promoters believed the eucalyptus could be used for making a number of materials: timber, fuel, medicine, wood pulp, honey, and both medicinal and industrial oils. Not only could eucalyptus grow quickly in many conditions, but, in several species, when the tree’s cut down even to the roots new stems sprout back up. It all seemed too good to be true. Later, it turned out, it was.

The eucalyptus was first planted in California in the mid-19th century:

Following its spread throughout Europe, northern Africa, India, and South America, settlers in California became increasingly interested in the eucalyptus. Not only was eucalyptus a fascinating novelty, but the California Gold Rush of the late 1840s and early 1850s created high demand for wood for constructing buildings and for fuel. Deforestation had become a serious concern, so much so that the California Tree Culture Act of 1868 was created to encourage people to plant more trees, particularly along roads. Many entrepreneurs rushed to capitalize on the situation.

The craze for planting eucalyptus spread from San Francisco to Santa Barbara:

Ellwood Cooper, educator, entrepreneur, and one of the key individuals who helped the eucalyptus take off in California, is a local legend here in Santa Barbara. After seeing eucalyptus in the San Francisco area, Cooper settled down in Santa Barbara in 1870. On his ranch, among many different types of produce trees (including olives, walnuts, and figs), he grew over 200 acres of eucalyptus. The eucalyptus forest he started lives on to this day at the Ellwood Bluffs. Cooper became a vocal advocate for the eucalyptus, emphasizing its unique, aesthetically pleasing appearance, as well as its useful qualities. He even wrote the first book in the U.S. on the trees. Eucalyptus became very appealing to foresters in the 1870s and 1880s as native hardwoods were being severely depleted.

Starting in the 1870s, the first large-scale commercial planting of the blue gum eucalyptus (E. globulus) began. The blue gum, a mid-sized eucalyptus reaching around 150 to over 200 feet tall, is the most common eucalyptus in California. These trees are easily recognized by their waxy blue leaves and a grayish bark which reveals a smooth, contrasting yellowish surface when the bark sheds off in long strips. As with many other eucalyptus species, sprouts can grow back from a fallen tree stump.

By the early 20th century, the eucalyptus tree became ubiquitous in California — and big business:

By the early 1900s, the get-rich mindset had caused many aspiring forest tycoons to plant countless acres of eucalyptus in hopes of selling the timber for a tidy profit. It’s estimated that there were over 100 companies involved in the eucalyptus industry at this time, and they changed the landscape of much of California.

However, the tree had its shortcomings:

Sadly, most of these schemes went the way they infamously did for Frank C. Havens. Havens was an Oakland developer who opened a mill and planted eight million eucalyptus trees in a 14-mile-long strip from Berkeley through Oakland. But when he came to sell the timber, it was found that the trees were too young to make suitable wood; the young wood had an irregular grain and it bent, cracked, and shrank when dried. It is true that eucalyptus trees from Australia could make good timber, but those trees were decades or sometimes centuries old. It was soon found that eucalyptus trees would need to be at least 75 or 100 years old for good lumber. The young wood didn’t even make useable fence posts or railroad track ties, both of which decayed rapidly. Havens closed shop.

Other options for selling California-based eucalyptus products were grim. In the early 1920s, it was realized that California eucalyptus oil wasn’t nearly the same quality as foreign-made oil, again mainly from Australia. The wood became increasingly sold just for fuel, but cheap electricity and gas soon replaced it. By 1950, eucalyptus trees were primarily grown in California as ornamentals or windbreaks. The trees had failed to live up the many premature claims and hopes.

Eucalyptus trees can self-propagate where weather conditions allow:

Blue gum can be invasive in California, aggressively spreading from its original planting if enough water is present, such as in the form of fog. The bark strips dropped by the blue gums are extremely flammable, which can lead to intense fires, such as the Oakland Firestorm of 1991.

As I mentioned in my previous post in the comments, an aunt and uncle of mine lost their custom-built house in the Oakland Firestorm, which was devastating. They later moved to southern California, along the coast.

Their house in the Oakland Hills was beautiful, but the area was surrounded by very tall eucalyptus trees, which, as the article says, contain flammable oil.

The Wikipedia entry describes the historical severity of the fire, which occurred on Saturday, October 19 that year:

The 1,520 acres (620 ha) destroyed included 2,843 single-family dwellings and 437 apartment and condominium units. The economic loss from the fire was estimated at $1.5 billion ($2.7 billion in 2022 dollars^[2]).^[1] …

The fire started on Saturday, October 19, from an incompletely extinguished grass fire in the Berkeley Hills, northeast of the intersection of California State Routes 24 and 13 (0.5 mi (0.8 km) north of the Caldecott Tunnel west portal). Firefighters fought the 5-acre (2.0 ha) fire on a steep hillside above 7151 Buckingham Boulevard, and by Saturday night believed it was under control.

The fire re-ignited as a brush fire shortly before 11:00 a.m. on Sunday, October 20 and rapidly spread southwest, driven by wind gusts up to 65 mi (100 km) per hour.^[4]It quickly overwhelmed local and regional firefighting resources …

The fire began generating its own wind, the defining characteristic of a firestorm. The superheated fire-driven winds combined with warmer, drier air east of the Berkeley Hills, and interacted with the ambient cooler, more moist Bay/Coastal air to create erratic, dangerous gusts, which helped produce numerous rotational vortices. All of these combined to help spread the fire, tossing embers in all directions. The wind was so strong that it also blew debris across the bay into San Francisco. Ash fell onto the field of Candlestick Park where the Detroit Lions and San Francisco 49ers were playing during that afternoon.^[5] …

By mid-afternoon, the wind had slowed and shifted to the west, driving the fire to the southeast. At about 9:00 p.m., the wind abruptly stopped, giving firefighters a chance to contain the fire.^[6] …

In terms of alarm assignments, it was the equivalent of a 107-alarm fire.

For a variety of reasons, the firefighting teams were initially overwhelmed by the firestorm. The winds were gusting at times in excess of 70 mph (110 km/h), creating erratic and extreme fire behavior. Flames took out power lines to seventeen pumping stations in the Oakland water system. Outside fire teams faced various equipment compatibility issues such as hydrants having the wrong size outlets for the hoses used by neighboring counties. Oakland was also not able to communicate with many mutual aid resources due to antiquated equipment and lack of access to statewide radio frequencies brought on by the budget restrictions in the preceding years. In some areas, firefighters simply ran out of water, as there was no power to refill the emptied reservoirs.^[8] Additionally, many narrow, winding roads in the area were crowded with parked cars, including many in front of fire hydrants; this prevented fire trucks and ambulances from getting to certain areas and connecting fire hoses. The general situation was one of chaos and panic among residents in the area.

The most important factor was the rapid spread of the wind-driven fire. Before most of the firefighting resources could be brought to the scene, the fire had established a large perimeter. At the fire’s peak, it destroyed one house every 11 seconds. By the first hour, the fire had destroyed nearly 790 structures. In addition to the winds and the heat, an important factor in the rapid spread of the fire was that it started in an area that was at an interface between developed and undeveloped land. Many of the first dwellings to burn were surrounded by thick, dry vegetation. In addition, the nearby undeveloped land had even more dry brush. Other factors included many wood shake/shingle roofs which were easily ignited by embers, and the use of wood chip mulch in landscaping around buildings, which was blown around spreading embers and igniting vegetation across streets.^[9]

It was a horrible disaster and made the news worldwide.

Returning to the Santa Barbara Independent article, Australia has mitigating factors which make the eucalyptus less dangerous:

Because most eucalyptus trees were grown from seeds from Australia, few eucalyptus insect pests traveled with the eucalyptus to their new homes. Fifty-seven Australian mammal species that normally live in eucalyptus groves, including koalas, wallabies, and pandemelons, as well as over 200 bird species, didn’t make the voyage either. Because the eucalyptus leaves and bark are poisonous, the mammals that feed off of it had to evolve mechanisms to deal with these toxins. Other mammals won’t eat the eucalyptus. Overall, this results in a small degree of species diversity in eucalyptus groves. Australian plants and animals never arrived; native plants and animals are pushed out. While the eucalyptus is certainly not as devastating to its new home as some non-native plants and animals have been, its story should still serve as a cautionary tale: Think before you plant.

Unfortunately, no mention was made on Wikipedia or the Independent of the importance of proper land management. There were way too many eucalyptus trees when I last visited my aunt and uncle in 1991, just months before the fire.

The latest wildfire news in 2023 is that they are raging in parts of the Canary Islands and in Canada’s Northwest Territory.

Such disasters can be avoided.