Notes from a California naturalist

For the final field trip of the quarter for Introduction to Field Research and Conservation, I took the class to the Landels-Hill Big Creek Reserve. Located in the Santa Lucia Mountains south of Big Sur, Big Creek was the fourth of the UCSC Natural Reserves we visited this quarter. The site is rugged and spectacular, and because it's not open to the public we were the only visitors there. There's something truly special about arriving at a campsite after dark (which most of us did) and waking up to find that you've landed in paradise. And realizing that you haven't pitched your tent in poison oak!

Saturday 07 May 2022

We had about a day and a half at Big Creek. Saturday we went on a hike that was much longer and more grueling than the gentle saunter I had promised the students. If I get to teach this class again and return to Big Creek, I now have better plans for how to manage things. We did hike through areas that burned in the Dolan fire in 2020, and were able to see first-hand now the landscape is recovering from that disturbance.

First, some facts about the Dolan Fire. It was started in the Los Padres National Forest in August 2020 by a man who was convicted of arson, throwing rocks at a vehicle, cultivating marijuana on public lands, and 12 counts of animal cruelty; this man, whose name shall go unmentioned here, was sentenced to 24 years in prison just a few days ago. The fire burned over 124,000 acres, cost the state $63 million to fight, destroyed 10 residences and four other structures, and damaged nesting sites for California condors, resulting in the deaths of 12 of the endangered birds. One of the casualties of the fire was the outhouse at the Redwood Camp campground, which is where we were camping. The outhouse had been rebuilt recently and was brand spanking new when we arrived.

Yes, it's a lovely outhouse, but I really took this photo to show the burnt trees. Redwood Camp is situated alongside Devils Creek, in the redwood forest. The fire came right down to the road and scorched trees along the canyon wall. Many dead trees had to be removed and trails cleared before Big Creek could reopen.

Our hike-that-was-more-than-a-saunter took us up the fire road to Whale Point, where we had spectacular views of the Santa Lucia Mountains in one direction and the Pacific Ocean in the other. Along the fire road our guide showed us fire damage to the redwood forest, and pointed out signs of recovery.

Redwoods are adapted for fire. They have a thick bark that shields the inner living tissue from damage, so long as the fire isn't too hot. The outermost layer of bark is frizzy and burns really fast, so a redwood on fire blazes like a match catching for a few seconds, then goes out. Old redwoods have few, if any, branches near the ground, so a low temperature fire at ground level would cause very little damage to a healthy tree. Fire clears out the underbrush and opens up the canopy, creating an opportunity for some young sapling to reach for the light. Fire suppression, on the other hand, allowed the accumulation of several decades' worth of vegetation, and when the Dolan Fire came through it burned hot and furious.

I knew, of course, that redwood trees are clonal. They sprout new trees from the roots and can eventually form "fairy rings". These occur when a mother tree puts up a ring of clonal offspring. Eventually the mother dies, leaving a ring of trees surrounding either a stump or an open space. We see in the Santa Cruz redwoods all the time.

What I didn't know, but learned at Big Creek, was that redwoods also have epicormic growth, in which new shoots originate from the beneath the bark of the tree, sometimes halfway up the trunk.

Epicormic buds lie dormant underneath the bark layer, their growth suppressed by hormones released by active shoots higher up in the tree. When those higher shoots are damaged, the cessation of hormones allows the epicormic buds to begin growing. The selective advantage of sprouting new growth halfway up the tree is that the new shoots have less far to grow to reach the sun. With redwoods being so tall, an epicormic bud located halfway up the trunk has a major leg up on the competition trying to grow from ground level.

However, that doesn't mean that many trees damaged by fire don't grow from roots. We saw lots of those, too. Our guide said that post-Dolan some redwoods grew from root sprouts and some from epicormic buds, and that there wasn't really any rhyme or reason as to which trees did which.

These young trees sprouted in 2021, a few months after the Dolan Fire was extinguished on 31 December 2020. The first year's growth is the dark green color. The new growth added in 2022 is the brighter and paler green. Here's another young tree where the color between the 2021 and 2022 growth is more striking:

The reward for the hike was a long rest at Whale Point, which we started calling The Top of the World. Because with views like this, who can argue?

Sunday 08 May 2022

After breakfast on Sunday the students packed lunches and dispersed to work on their rapid research projects (RRPs). The RRP is a field exercise in which students devise an entire research project, from initial observations and questions to final presentation, in a few hours. I've found it to be a very effective assignment, because it forces students to simplify and narrow their ideas. They simply can't get too carried away if they have to make a poster and present it to their classmates in half a day. When students are working on RRPs my job is to keep them focused and on-task. Sometimes this is easier said than done. We had students working in the forest, in the creek, and on the beach.

At Big Creek there's a new classroom built down by the beach. No matter where the students did their actual research, we would all meet at the classroom to build and present posters.

It's hard to see in the photo, but to the right of the middle of the building, in the corner of the ell, there's a glass door. Directly across on the opposite side of the building there's another glass door, so you can see all the way through the building. We discovered that this is a problem, as two birds had tried to pass through the building and smacked into the glass. They were both dead. So on the spur of the moment I turned it into an impromptu lesson.

I couldn't ID either bird off the top of my head, so a handful of students and I sat down with the birds and some field guides to study bird anatomy and identification.

We talked about different types of feathers—primary and secondary flight feathers, coverts, tails—and their functions. After working through descriptions in the field guides I was pretty certain that the larger bird was a Swainson's thrush (Catharus ustulatus) and the little yellow bird was some sort of warbler. It was a good lesson for the students, because we looked at physical descriptions and geographic ranges, and could not come up with a definitive answer. I took several pictures of both and uploaded them to iNaturalist when we got home. We were correct about the brown bird, and the little yellow one ended up being an orange-crowned warbler (Leiothlypis celata).

The RRPs were the last part of the field trip, and after that we packed up and headed out. The students went straight back up the coast to get home, and saw three California condors from the highway. Alex and I drove back up to Whale Point where it was really windy, just to see condors, and didn't see any. Go figure. At least I had my camera with me and could take real pictures. And it was another beautiful day.

I am one fortunate woman, because I get to call this work!