Long Beach has quite the urban canopy, for which the local residents should be proud. However, a new and particularly troubling group of organisms have begun popping up throughout southern California, and they are poised to decimate the beloved and beautiful Indian laurel figs (Ficusmicrocarpa) that comprise much of the city’s urban forest.
The problematic organisms threatening southern California’s fig trees are all species of a fungal genus calledBotryosphaeria. The genus is comprised of nearly 200 species, although only a handful is pathogenic for fig trees. Nevertheless, scientists are often able to identify more than one member of the genus when studying colonized trees. The disease caused by the fungi is generally called branch dieback disease orBotryosphaeria canker.
Branch dieback disease which typically afflicts a single branch at the outset. Symptoms may include browning foliage, premature leaf drop, visible cankers on the branches and twigs and the exudation of sap (gummosis) from the branch or twig. Shortly after the first signs appear, the infection tends to spread in patches throughout the canopy.
Eventually, the fungus often finds its way down through the primary branches of the tree and the trunk. Trees with such advanced fungal growth typically die within a few years.
Prepare for a Change in Scenery
According to researchers studying the fungus’ effect on our local trees, approximately 25 percent of the fig trees in southern California are already infected. And because the disease often advances rapidly, many scientists suspect that all of the Indian laurel figs lining the streets of Long Beach will be dead within the next decade or two.
This will drastically alter the visual appeal of many of Long Beach’s streets; Indian fig laurels were the most commonly planted street tree during the mid-20th century and they cover much of the city. Most of these trees will require removal, and although they will be replaced with new trees, these trees will take decades to grow to the size of the mature figs currently in place.
It’s Not All About Looks
The plight of our region’s fig trees is not only an aesthetic problem: The loss of so many mature street trees will lead to a litany of other problems, including:
- Higher Temperatures — Unprotected by the dense canopies of figs, neighborhood streets will become much warmer than they previously were.
- Reduced Biodiversity – Once the figs have died off, the birds, bees, and butterflies of the region will have fewer resources at their disposal, which may lead to population declines.
- Dirtier Air – Mature fig trees have a lot of surface area, which means they withdraw significant amounts of particulates and toxic gases from the air.
- Reduced Property Values – While the loss of Long Beach’s fig trees is unlikely to destroy the local housing market, it will probably allow homeowners to demand as much as they would if the trees were still in place.
- Increased Expenditures – As the fig trees are removed, they’ll require replacement with trees that are not susceptible to branch dieback disease or any other local threat.
It is important to note that, with early detection and prompt action, many Botryosphaeria infections can be stopped in their tracks by removing the affected limb. Your fig trees will still remain vulnerable to future fungal attacks and they will require removal at some point, but that doesn’t have to be today.
If you suspect that your fig trees are suffering from branch dieback disease, or you observe any type of dieback in your tree’s canopy, contact your friends at Evergreen Arborist Consultants and let us assess the problem. We’ll provide you with a recommended course of action and help you make the most prudent decisions regarding the future of your tree.