Life in a Harsh Environment: Spring Wildflowers in the Red Hills Area of Critical Environmental Concern

Ceanothus, Poppies, and Goldfields in the Red Hills area of the Sierra Nevada foothills.

Welcome to the Red Hills "Area of Critical Environmental Concern", a 7,000 acre preserve in the Sierra Nevada foothills near the village of Chinese Camp. We paid a visit today to see what flowers were out and about in this horrific drought year when much of the state has received hardly a quarter of the normal amount of rainfall. It's a fascinating area to explore, despite the somewhat plain appearance of the hills. The interest lies in the struggle for life in this tough environment.

Brodiaea, or Blue dicks, Dichelostemma capitatum. Can you see the tiny mite in the flower?

It's not exactly harsh as far as the climate is concerned. Sure, it gets hot in the summer and the rain falls only in the winter and spring. But it rarely gets cold enough for snow, and the nearby hills include thick forests and brush. In the Red Hills, one is struck by the near total lack of grass covering the hillsides. Although oak trees are common throughout the region, few if any take root in the Red Hills. And there are sharp vegetational boundaries. The oak woodland and grasslands simply end, and the barren ground begins.

Indian Paintbrush

The problem is the soils. The underlying rocks are composed of serpentine and other ultramafic rocks derived from the Earth's mantle, the thick layer that lies beneath the oceanic and continental crust. The mantle rocks are rich in iron, nickel, chrome, and other metals that are toxic to most plants. The soils are also deficient in nutrients that plants generally need.

I don't know these diminutive flowers. Any ideas? I'm guessing Baby Blue Eyes (Nemophila menziesii) PS: Nope, it's
Bird's Eyes (Gilia tricolor), thanks Russ Cary.

These tough conditions mean that many plants can't grow on these soils, but others that are usually crowded out by grass and weeds can either tolerate the serpentine soils, or even thrive. Some 250 plants have been found in the Red Hills, including a number of endemics that are not found outside the serpentine exposures.

Five spot (Nemophila maculata): It's strange, but for all the years we've been coming out here, I have never noticed this species before. It is quite pretty!

For years the Red Hills were an abused landscape. Despite the proximity of the Mother Lode gold veins, very little gold was found in the hills (serpentine is not a gold-bearing rock). Nothing of value could be grown in the soils, and so the land was used as an illegal garbage dump, shooting range, and off-road vehicle course. As the uniqueness of the hills became better known, the Bureau of Land Management acted to protect and clean up the region. Today there are trails and parking areas for visitors. It is especially popular in the spring when the wildflowers are at their best. As mentioned before, the year has been horrifically dry, and we are indeed in the midst of the worst drought ever recorded. The flowers are getting started, but it remains to be seen whether they will thrive through the spring (there is a possibility of some rain this week).

As we left, we saw a particularly rich patch of poppies and brodiaea, but such richness was the exception. For the most part, the flower show hasn't really started yet (if it starts at all).

We left the Red Hills and headed south on Highway 49 on the way to Marshes Flat Road. Along the way I took a deceptive picture (above). Yes, it sure looks like an explosion of California Poppies. It's enough to cause one to say "What drought?". But take a look at the larger context of the picture (below)...

The flowers thrive because runoff from the pavement gives the soil the extra moisture they need. There are few flowers beyond the edge of the highway. Still, the color was beautiful, and I hope the rain this week will keep the show going a little bit longer before the long, hot and dry days of summer.

There were more (and different) flowers on Marshes Flat Road. We'll see those in another post.

Red Hills Redux

In late March, I paid an early spring visit to a unique geologic locale in the Mother Lode of the Sierra Nevada, the Red Hills Area of Critical Environmental Concern, which is such a better moniker than such things as "park" or "wilderness". So much easier to say or write! It was an ideal example of the "Other California", those places that never seem to show up on the postcards. At the time, we were enjoying the early blooms of the many endemic and unusual flower species growing on a serpentine soil that prevents the usual grasses and oak trees from flourishing.

It was an uneventful afternoon of an uneventful week, so we hopped in the car and drove back up Highway 132 towards Chinese Camp to see if any of the flowers were still there six weeks later. Things were certainly drying up, but plenty of flowers were still blooming along the small creeks.

There was still a lot of daylight left, so we figured why not head up towards the high country and figure out was blooming up there? So we jumped onto Highway 120 towards Yosemite National Park. As tempting as it was, by the time we reached the Rim of the World Overlook, it was nearing 6:00 PM, and Yosemite itself was out of the question (that trip will have to wait a few days).

The Rim of the World Overlook provides a rather spectacular view into the vast gorge of the Tuolumne River, which cuts into the westward tilting block of the Sierra Nevada province. The Tuolumne had the longest glaciers during the ice ages, but they never reached this far. This is a river-carved canyon.

The two forks of the Tuolumne meet below the view point some 1,500 feet below, but the rivers could be clearly heard. The viewpoint lies very close to the boundary between the granites of the Sierra Nevada batholith and the early Paleozoic metamorphic rocks of the Shoofly Complex, one of the oldest rocks found anywhere in the Sierra Nevada.

By the way, yes, there were a great many flowers to be seen at the 3,000 foot level of the Sierra. The highway was bedecked in many places with purple and white lupine, with the occasional splashes of red Indian Paintbrush. The scene below was just off the upper end of Ferreti Road, which winds through a resort complex at Pine Lake near Groveland.

We capped off the evening with a nice selection of Mexican cuisine at Alfredo's in Sonora, a small restaurant that I recommend!

The Other California: There's an Endemic in those Red Hills!

Oh, that's right, it's epidemics we're supposed to worry about. An endemic refers to plant species found in specific limited locations. There are a number of these in the Red Hills "Area of Critical Environmental Concern", a rather high-falutin' name for an area that less than two decades ago was barely more than an open garbage dump scarred by numerous off-road vehicle trails. The rare and endemic species are there for a very geologic reason, the subject of this post.

The Other California is my continuing blog series on those places in California that people don't generally find on the postcards at all our tourist traps. I've been following a regional theme, traveling through the northernmost provinces, but the Other California has a temporal pattern as well, and late March is the perfect time to talk about the Red Hills, located in the Sierra Nevada Mother Lode near the Gold Rush town of Chinese Camp (I talked about the area around La Grange a few days ago for the same reason).

Much of lowland California is currently covered with a green carpet of grass (mostly of exotic and invasive origin) along with the occasional oak tree, but as you can see in the pictures above, there are a few places where the grass and oak trees are missing, and a profusion of flowers and scattered pines thrive instead. Why are the oaks and grass missing?

The Mother Lode is famous as the source of the ores during the Gold Rush in 1848-53, and many people know of the association of quartz veins with the gold. What is perhaps less known is that the Mother Lode consists mostly of metamorphic rocks like slate, greenstone, and marble, not the granite that is found in the higher parts of the Sierra Nevada. These metamorphic rocks are the twisted and baked remains of sea floor muds and silts, lime from tropical reefs and shelves, and volcanic rock from the oceanic crust. These collections of crustal rocks (called "exotic terranes") were transported across the Pacific Ocean and slammed (in the geologic sense; they moved at maybe 2 inches a year) into the western edge of the North American continent, mostly in the late Paleozoic and Mesozoic eras (the Mesozoic, from around 251 to 65 million years ago, is best known as the "age of the dinosaurs"). The different terranes are separated from one another by major fault systems.

At times the crustal terranes also include rocks from beneath the crust. This rock hails from the underworld of the earth's mantle, and includes dunite and peridotite, composed primarily of the mineral olivine (known to most people as the gemstone peridot). The rock readily alters to serpentine, California's state rock. These rocks are also collectively called ultramafic rocks, for their high content of magnesium and iron (fe, the 'fi' part). They also contain small, but significant amounts of nickel and chrome.

When ultramafic rocks are brought to the surface, they are far out of chemical equilibrium with the ambient conditions, which means they are easily attacked by oxygen, water and organic acids. Clay is a common product of this process, as well as red or yellow iron oxides (from which the Red Hills take their name). The surface layer resulting from this weathering process is of course soil. We tend to think of soil as a rich surface layer that supports plant life, but some soils lack the necessary nutrients for most kinds of plant growth. This is definitely the case for soils developed on ultramafic rocks, which lack nitrates, phosphorus, and potassium. To make things worse, chrome and nickel are actually toxins. Hence, only specialized species can thrive on these rocks.

The shrubby Ceanothus, or Buckbrush (above) and Gray Pine (below) are two plants that are more or less indifferent to the odd soil conditions. They grow elsewhere, but compete very well in ultramafic soils. A large number of flower species are also indifferent to the soils, but the only grasses found in the region are native species. The European and Asian grass species that have overwhelmed most of the prairies in the Central Valley, Coast Ranges and Sierra foothills cannot grow on the serpentine soils.

There are a number of endemic species that grow on these soils, and at least one is found nowhere else in the world (California verbena, Verbena californica). Other rare endemics include Rawhide Hill onion (Allium tuolumnense), Layne's butterweed (Senecio layneae), Congdon's lomatium (Lomatium congdonii) and the Red Hills soaproot (Chlorogalum grandiflorum). A fairly common serpentine endemic is the Milkwort Jewelflower (Streptanthus polygaloides). Alas, I arrived very late in the afternoon and had no time to search them out (and to be truthful, I am better at identifying rocks and minerals).

Though closely associated with the rocks of the Mother Lode, the serpentine and dunite were remarkably free of gold, and so the Red Hills were mostly ignored by the miners. Farmers couldn't grow much in the soils, and grazing conditions were not favorable, so the when the federal government came into possession of these lands in 1848, they couldn't even give them away! So this swath of land, about 7,000 acres worth, was administered, somewhat indifferently, by the Bureau of Land Management. The landscape suffered the abuses of modern civilization, with trash heaps, motorcycle trails, and unrestrained target shooting. The recognition that the area was a unique geologic and biologic treasure led to the restriction of shooting and off-road vehicle use in 1991. Private groups assisted in cleaning up the trash heaps and a trail network was established, so today the Red Hills are a delightful place to visit, especially in the spring when the wildflowers are at their stunning best. And I could be wrong, but I don't think I've seen any postcards with pictures of the area.

If you want to learn more, or pay a visit, information about the Red Hills can be found on this BLM website , and the nature trail brochure PDF can be found here.