Bobcat Fire Burn Scar Update: 532 Days Post-Fire (feat. ceanothus)
(Disclaimer: I am not a bonanist; I'm a pastoralist. So although I'm doing my best to document what's happening in our burn scar, I might get some things wrong. I welcome corrections!)
Blooming Mojave ceanothus. Image from worldbotanical.com.
It's been a long time since I've had anything interesting to report from the burn scar. Even the resprouting shrubs take a break for the winter. We've had a few well-spaced snow storms, bringing our local precipitation total so far to 8.16", and now the soil is greening up here and there with annuals and new shrub seedlings. SPRING!
Wide shot of the burn scar in an especially green area where water comes out of a small canyon.
For the most part it looks similar to early Spring 2021, the first spring after the fire, with the exceptions of a little bit more cover of annuals coming up in some areas, and a peppering of larger seedlings from the first spring that managed to survive the dry season. In Issue 24 of The Obligate Resprouter newsletter, published May 2021, I photographed and wrote about a nearby burn scar in it's second spring. I'll visit that site again this May to continue my tradition of peaking into the ranch's future. But for now it's time to watch the second spring unfold right here at home.
San Gabriel Mountains endemic Opuntia basilaris var. brachyclada “short-joint beavertail”, in the background the dried remnants of last year's spiny poppies, whispering bells and tobacco. I wrote in detail about this amazing survival succulent in Issue 11 of The Obligate Resprouter newsletter, published January 2021. Looking back on this early issue of the newsletter, which is all about the idea of survival, I can see that I was barely doing it myself. But it's still one of my favorite issues, because of the joy in discovering the resilience of this little hero among local flora.
Calflora lists Desert ceanothus and Mojave Ceanothus separately, and indicates later blooming for the Mojave variety.
In early February I came across a mystery seedling that I hadn't noticed either on the ranch during the first spring, or in my nearby second spring investigation. The tiny clumps of tight fleshy leaves were spread over a pretty large area, with each seedling separated by several feet. It's easy to miss them, but once you start looking for them, they are everywhere. Thanks to the help of some kind people in the California Native Plant Society's Facebook group, I learned this is a ceanothus, probably Mojave ceanothus based on our location. Reading about types of ceanothus is confusing. Sometimes Mojave ceanothus is categorized as a type of Desert ceanothus, and sometimes they are presented as peers. The number of scientific names used to refer to either, or sometimes both, is long. Most commonly both are categorized as subspecies of Ceanothus greggii. Perhaps this is not quite settled yet, or is a result of the prevalence of natural hybridization between ceanothus subspecies. I've given up on these details for now to focus my learning on the traits shared by these types of ceanothus and especially their relationship with fire.
Ceanothus seedling discovered in the burn scar on the ranch in early February.
Ceanothus are members of the Buckthorn family (Rhamnaceae) of mostly flowering shrubs and occasional trees and vines, existing worldwide but most prevalent in tropical and subtropical environments. The Chinese jujube is a delicious and familiar member of this family of plants. Ceanothus contributes 50-60 of the almost 1000 species in the buckthorn family and is native to North America, with most of its diversity found in the West. Referred to by many names including buckbrush, California lilac, wild lilac and soap bush, all ceanothus have the helpful habit of fixing nitrogen in the soils where they make their homes. Ceanothus leaves are palatable and nutritious for foraging animals including our local mule deer, seedlings are often eaten (and killed) by rabbits, seeds are consumed by quail and rodents, and a tea of the leaves has been enjoyed by both America's indigenous inhabitants and also early settlers as a substitute for black tea. In the wild, the germination of seeds of ceanothus occurs only in response to the intense canopy fires typical to chaparral.
A stand of ~12 year old Mojave ceanothus in the Largo Vista Fire (2010) burn scar.
Desert ceanothus are found throughout the southwest, as far north as Utah and as far south as Oaxoaxa, mostly in chaparral ecosystems but also in piñon-juniper woodland. Here is the San Gabriel Mountains, they are common on the North-facing slopes. On the other side, in the Los Angeles foothills, other varieties of ceanothus are more common including Bigpod ceanothus (Ceanothus megacarpus). Once I identified my seedling and looked up photos of the mature plant, I recognized it as a rare but existing shrub on the ranch in the beforetimes. I had never seen examples in the mature chaparral or piñon forest, but in areas cleared or otherwise disturbed several decades earlier, this shrub would appear occasionally among the buckwheat and desert almond. Desert ceanothus shrubs will eventually die out in areas that go fire-free for ~100 years. Just across the street from the ranch in the burn scar of the Largo Vista Fire (2010), which is dominated by resprouting Tucker oaks, Mojave ceanothus is the dominant understory shrub.
The tops of these ~12 year old plants look a lot like the seedling, which I should have noticed earlier when I was trying to ID! (Lola the bulldog butt cameo.)
I haven't seen my 12-year-old ceanothus plants bloom yet, but it's too early in the season. Also I'm not sure if they are mature enough. I've read they reach sexual maturity anywhere from 3 years to 15 years after germination, quite a range.
So why didn't I see these last year? From all I've read, MOST of the seedlings germinate in the first year, with only stragglers coming on in the 2nd or 3rd year after fire. I have a few theories:
I didn't notice them because I'm still learning
The goats ate them (goats are no longer allowed to forage in the burn areas)
They were eaten by rabbits (some reports say only 7% survive due to rabbits)
Fruits of Mojave ceanothus. Photo from worldbotanical.com.
Does this story of a semi-tropical, fire-germinated, short-lived shrub magically appearing after a fire SOUND FAMILIAR? It should. Because it exactly the same story that I wrote about in this previous entry regarding California flannelbush.
The peak for both of these plants will occur between 20 and 30 years after the fire, so around 2040-2050. I will be 70-80 years old. I can't wait to look out my window at the hillside in the spring and see a sea of tiny white and giant yellow flowers where before there was only silvery sagebrush.
After the fire, before I knew better, I fell into the trap of talking about the "recovery" of the land. Of course now I realize the current state is no less natural and beneficial than the mature state before the fire. In fact I'm sure its better in the big picture, the picture that includes in one dimension the whole San Gabriel Mountains (maybe the whole earth), and in the other dimension, the thousands of years making up several fire cycles (maybe all of time). Actually it requires a lot of luck for a short-lived human to get a chance to live in this beautiful, fire-adapted landscape at both the end and beginning of its long fire cycle. Lucky me. In the language of Wendell Berry, I am a placed person.
Further reading/listening/looking:
Ceanothus seeds don't germinate in response to low intensity prescribed fire.
(4 min listen from the Montana Natural History Center)
USFS Fire Effects Information System entry on Desert ceanothus
The prize for best photos of Mojave ceanothus on the web goes to birdandhike.com
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