Adiantum aleuticum

Walking around the redwood forest, it’s almost impossible not to come across ferns. We have several species growing around our home and today’s post is about the native western maidenhair fern, sometimes called the five-fingered fern, botanical name Adiantum aleuticum.

These delicate-looking ferns are found mostly in western North America from Alaska down to Mexico. (It’s more common along the coast but can be found in the Rockies and as far away as Maine, Quebec, and Newfoundland.) They prefer to grow in shady, moist, humid forests, along streams and often thrive in the spray of waterfalls.

The western maidenhair is a deciduous fern, shedding its leaves in the winter. Like all proper ferns, the western maidenhair reproduces with spores rather than seeds. The spores develop on the underside of the leaves, ripening and releasing in the summer and fall. New growth emerges, bright green, in the early spring and leaves darken by the fall.

The leaves, or fronds, extend from dark brown or black stalks. They grow wide rather than tall, with fronds reaching one to three feet in length.

[Photo credit: me, jerry1 via iNaturalist, and Morgan Stickrod also via iNaturalist]

western maidenhair fern

closeup of western maidenhair fern

wide shot of western maidenhair fern

Three

Next in this series on the coast redwood forest floor is the Pacific trillium, also called the western wakerobin, botanical name Trillium ovatum.

Pacific trillium is found in moist coniferous forests from central California up through Oregon and Washington into southern British Colombia and also inland in Alberta, Idaho, and Montana (and further?)

This trillium is a long-lived native perennial herb. It reaches maturity (and starts reproducing by seed) at about 15 years of age and can live as long as 70 years. The stem of a mature plant will grow about a foot to a foot and a half tall with three broad, pointed deep green leaves about half way up. Sitting atop a stalk that rises well above the leaves is the flower which has three sepals and three distinctive petals that start off white, move to a rose shade, and then to a beautiful lavender, maroon, or purple.

Around here, the Pacific trillium grows in the shade of the redwoods and Doug firs, in boggy areas, and along streams. It’s one of the first flowers to bloom in our forest, starting in February and continuing through June.

[Photo credit: Deanna L. Pierce, ekohner via iNaturalist, and John D. Anderson via Flickr]

closeup of pink pacific trillium flower

pacific trillium with white flower

pacific trillium with purple flower

Bark

In 1928, a man named W.O. Miller bought a small parcel of land at the intersection of two creeks in the Middleton Tract — a new residential community deep in the redwood forest of the Santa Cruz Mountains. It’s probable, but not confirmed, that Miller hired a Finnish American from Boulder Creek named Leander Erickson and his sons to build a redwood log cabin on the site. The home was completed that same year.

The trees for the building were second growth coast redwoods, probably cut from a farm about a mile and a half up the mountain side. The original forest in the area was clear cut starting about half a century earlier, so these were “young” redwoods, about a foot in diameter.

I don’t have any photographs of the cabin being erected, but I’ve included a photo of Erickson and sons building a neighboring cabin. (There were half a dozen log cabins built in the neighborhood around that time, and ours is quite similar to the one pictured.) As you can see from the photograph, it was all done by hand.

It’s interesting to me that so many early residents of this neighborhood chose to build with logs when dimensional lumber was readily available. Was it nostalgia? Something else? Another curiosity is that the log cabins built in the neighborhood were built with logs that retained their bark. Was this simply a Finnish style that Erickson knew and preferred? Or were there some other reasons for leaving the bark on?

I’ve read quite a bit about log homes since we moved here and it seems very common to strip the bark off of the logs for this kind of construction. The reasons are that it makes fitting and chinking easier and that bark is notorious for bug infestations and rot. Perhaps because these cabins are built from coast redwoods, which have a sturdy and highly bug resistant bark, there was simply no need to take the extra step of stripping the logs. Or maybe the more rustic look was just preferred? I honestly don’t know but it does make for an attractive cabin that looks right at home in the redwood forest. And, almost a century later, the logs still retain their bark with no signs of rot or bugs.

[Photo from the book by Sheri Jansen-Olliges, “From Timber Barons to Tree Huggers: The Story of Middleton’s Redwood Community”]

black and white photograph from the 1920 showing four men building a log cabin

Redwood Sorrel

The coast redwood understory is a fascinating place. Next up in our review is the native redwood sorrel, botanical name Oxalis oregana.

It’s called redwood sorrel because it prefers to grow on the redwood forest floor and it’s extremely common there, sometimes forming great expansive green carpets. It ranges mostly where redwoods do, following the coast from central California up through Oregon and Washington, and just barely into British Colombia.

Redwood sorrel is native herbaceous evergreen perennial that spreads by rhizomes (which are sort of underground stems) and seeds. It grows in dense patches, mostly about 8 inches tall, in moist, quite shady areas. Its leaves are each made up of three heart-shaped leaflets.

The leaves are actually really cool. Because these plants live in the deep shade under the great redwoods, they’ve adapted with super-sensitive leaves to photosynthesize with very little light. That would be problematic during mid-day in summertime when the sun is high enough in the sky to deliver direct light to the plants but the redwood sorrel have also adapted to close their leaves, like an umbrella, when the sunlight is too direct. They also use this folding technique to conserve water during dry times and to protect themselves from heavy rains during the wet season.

The plant blooms early spring through the end of summer. The small flowers are white to pink with five petals with lavender veins.

[Photo credits: Deanna L. Pierce, me, Ed Miller via iNaturalist, and Nick Doty via iNaturalist]

close up of redwood sorrel flower

redwood sorrel showing leaves closed in the sunlight

closeup of redwood sorrel leaves

carpet of redwood sorrel in front of redwoods

One Quarter

The CZU Lightning Complex fire is the most significant event to happen to the forest of the Santa Cruz Mountains since the clearcut era.

A while back I attempted to estimate the extent of damage by measuring the area of the fire and the total forested areas of the Santa Cruz Mountains using Google Earth’s handy area measuring tool. I came up with 17% (about 1/6th) of the forest impacted by this fire.

The only problems with my approach are that 1) I used Google Earth’s default satellite view to estimate the forest area based on color and it’s actually kind of difficult to distinguish forests from not-forest by eyeballing it like that. And 2) I used Google Earth’s somewhat crude polygon tool to create an imprecise outline to measure the areas so there was probably some error there.

Today, I decided to make a more serious measurement and so I did a bit of research and found the USGS’s National Land Cover Database. The NLCD uses Landsat satellite imagery to classify land cover. Adding that data layer to Google Earth, I was able to get a much better picture of the boundaries of the forest and even to see the composition of the forest from evergreen to mixed to deciduous.

Then, rather than using Google Earth’s crude measuring tool, I took screenshots from Earth and opened them in Photoshop where I could select color ranges and count pixels (pixel counts are found in the Histogram dialog.) This should be a much more accurate reading.

And here’s what I found. My initial calculation was close, but underestimated the size of the CZU fire damage. My first estimate was about 16% of the forest of the Santa Cruz Mountains in the burn area. With the new, hopefully more accurate approach, that estimate grew to 19% or almost 1/5th.

And with the NLCD data I was able to go a step further and focus in on just the evergreen stands which are primarily made up of coast redwood and Douglas fir. When I analyzed those areas I got an even larger number, 25%. A full quarter of the pure evergreens stands in the Santa Cruz Mountain was impacted by this fire.

Google Earth's satellite view of the Santa Cruz Mountains

NLCD 2016 Land Cover for the Santa Cruz Mountains

An Oak

This is an oak near the top of the mountain that I really like. It’s by no means the largest or the most majestic oak on my drive, but there’s something about its shape and where it sits on the ridge that’s held my attention over the years.

Oak tree against a blue sky

Sugar-scoops

Today’s walk through the coast redwood forest floor brings us to the adorable little sugar-scoop, also called lace foamflowers, botanical name Tiarella trifoliata. (Tiarella means “little tiara”.)

There are several varieties that can be found along the Pacific Coast from Santa Cruz up to Alaska, and inland as far as Alberta and Montana.

Our sugar-scoops are var. unifoliata. Rather than the more common three part leaves found in var. trifoliata, ours have a single-part, lobed, toothed leaf that looks kind of like a small maple leaf.

Sugar-scoops are a perennial herb that like moist shady stream banks and that’s where we find most of ours. They flower along a tall (one foot or so) stalk, primarily in June and July but occasionally starting as early as May and as late as September. The white flowers are bell shaped with five petals.

The name sugar-scoop comes from the shape of their seed pods which resemble tiny sugar scoops.

[Photo credits: me, Deanna L Pierce, Don Loarie via iNaturalist]

flowering sugar-scoop

sugar-scoop flower clusters along its stalk

close up of sugar-scoop flower

Progression

In the very early morning of Sunday, August 16th, a dry lightning storm started a bunch of fires all over the western slopes of the Santa Cruz Mountains. Five of those fires would become significant and eventually merge to form the CZU August Lightning Complex.

(There was a sixth nearby fire that you might be able to see as a small dot northeast of the complex perimeter, to the left of the “me” label. That fire was our initial worry because it was less than a mile from our house. However, before we were evacuated we were watching it closely and it didn’t seem to be growing. Turns out it wasn’t.)

From this progression map (in which I highlighted the first three days of fire growth) you can see that the southern-most fire, which was staffed well because of its proximity to residential areas, was completely contained and didn’t grow after that first day. The other southern fire over on the coast did grow some on the second day but it was apparently also well staffed. The three fires up north were woefully understaffed in these early days and burned pretty much unhindered.

On the third day, the fire absolutely exploded in size growing to over 40,000 acres and connecting four of the original fires into a giant “complex”. (We were evacuated late that afternoon.)

The fire would continue to grow over the next 34 days but it’s pretty wild to think that about half of the total burned area happened in the first 3 days of the fire.

(Thank you, Casey Dunn, for the maps.)

Fire progression map for the CZU Lightning Complex