Saturday, March 22, 2014

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.


Russ Cary said...

Nice photos! I believe your mystery flower is called Bird's Eyes (Gilia tricolor). You can often find lots of it near the beginning of the Hite Cove trail in the spring.

Andrew Alden, Oakland Geology blog said...

A thin iron-rich soil with little vegetative cover is typical of serpentine country, hence the name of the Red Hills.