Sierra Nevada Foothill Flora 2024-5

[Robert]

Autumn has descended on the Sierra Nevada Foothill region of Northern California. The photograph was taken from the orchard at our El Dorado County farm. The yellowish-brown trees in the distance are California Black Oak, Quercus kelloggii. The trees with green foliage are Interior Live Oak, Quercus wislizenii var. wislizenii. Blue Oak, Quecus douglasii and California Gray Pine, Pinus sabiniana are also very common savannah trees in this area.

In the next few days I will travel to the Deer Creek Hills in the Sacramento Valley abutting the Sierra Nevada Foothills near the border with El Dorado County. I will also be checking on the Serpentine barrens located a short distance south of our El Dorado County farm. Botanically, I do not expect to see much, as the rainy season has just started and most herbaceous plant species are still dormant.

[Robert]

On 5 December on my way to our El Dorado County farm, I took an alternate route to the southwestern corner of El Dorado County where the low elevation oak savannah ecosystem transitions to the open grasslands of the southern Sacramento Valley. To reach this area, I had to drive through an area of dense urbanization, where 40 years ago a thriving grassland ecosystem once existed. As I drove southward the urbanization abruptly ended and the road narrowed on its continuing southward path through an open oak savannah.



I eventually arrived at a low hill, elevation 810 feet (247 meters), where the Deer Creek Hills could be seen off in the distance to the west. The Deer Creek Hills are one of the few semi-intact remnants of the open grassland and oak savannah ecosystems in Sacramento County. Here the low elevation perennial, Delphinium variegatum ssp. variegatum and brilliantly colored Calochortus luteus can still be found in some measure of abundance. Here many Brodiaea Family species, Themidaceae, can be found blooming from early spring to early summer.



Off in the distance to the southwest, the western border of Amador County extends into the Central Valley. Many rare and endemic plant species can be found growing on the ultramafic soils of this area. The Ione Manzanita, Acrtostaphylos myrifolia, is one example. A number of distinct ecotypes can also be found growing on these ultramafic soils. For example, a number of years ago I found a distinct population of Arctostaphylos viscida ssp. viscida growing in this area. This population has very distinct intensely glaucous-gray leaves and a much more compact habit of growth than the type species.



With the autumn rains many annual species have germinated and are starting to turn the landscape green. Remnants of last year’s growth are still intact; however making a positive identification of many of the species is difficult to impossible at this late stage. The dry remains of Medusa’s Head, Elymus caput-medusae (pictured), were one of the few easy to identify species at this time. Klammath Weed, Hypericum perforatum ssp. perforatum and Turkey-mullein, Croton setiger, were also easily identified.  The dried remains of Avena species were still noticeable; yet making a clear determination between Wild Oats, A. fatua, or Sender Oat, Avena barbata, was not possible.



From the rise overlooking the Deer Creek Hills I drove northeastward through a number of plant habitats to arrive at our farm. Oak savannah was quite common. During this past summer and autumn of prolonged extreme heat, soil moisture levels became extremely low and have been slow to recover. After abundant precipitation in late November, the soil moisture content has recovered, however it is still only 80% of average to date. At lower soil levels, the soil is still extremely dry. The extreme temperatures and low soil moisture levels created conditions of great stress to the vegetation, especially on open southern exposures. In these locations many of the trees, Blue Oak, Quercus douglasii, in particular are showing signs of stress, however other plant species have been impacted as well.



Pictured, the distant hills are covered with chaparral vegetation. Our low elevation chaparral ecosystems are quite distinct. White-leaf Manzanita, Arctostaphylos viscida ssp. viscida and Chamise, Adenostoma fasciculatum var. fasciculatum, are two of the most common species associated with these low elevation chaparral ecosystems, however a large and very diverse set of plant species are associated with these ecosystems.

I was hoping to visit our local serpentine barrens on this occasion, however I had a malfunctioning data recorder at the farm that took considerable time to bring back to working order. Visiting the serpentine barrens will have to wait for another occasion.

[Robert]

January 2025 was dry in our part of Northern California. The precipitation abruptly ended on 4 January and there was no precipitation in our region until 31 January. We ended January with 1.43 inches (36.32 mm), which is 24.7% of average for the month of January. Since then, into early February, there has been abundant precipitation. As of 5 February we have already received nearly 100% of our average precipitation for the month of February. Dry periods like this during our winter precipitation season are not unusual.

Pictured above is a scene from the upper slopes of our El Dorado County property. Our property is situated in an oak savannah. Blue Oak (Quercus douglasii) is the dominant tree species. California Gray Pine, Pinus sabiniana, and Interior Live Oak, Quercus wislizenii, are also frequently found in this ecosystem, however generally in much lesser numbers.

The grasses consist entirely of non-native invasive species. Remnants of the native bunch grasses, which once flourished, are rarely found in our Blue Oak Savannah ecosystems today. The ecosystems in our region have been profoundly impacted and altered by the changes that have taken place over the last 300 to 400 years as foreign settlers moved into the region. Mining, agriculture, and the extraction of wood for fuel have completely obliterated or transformed most of our native ecosystems from their former state before 1600.



Pictured is a view to the east in the direction of the Sierra Nevada Mountains. So far this season, snow levels have been extremely high. To date, there has been no measurable snow at 4,000 feet (1,219 meters). At 5,000 feet (1,524 meters) there is currently no snow and the number of snow cover days at this elevation stands at 74% of average. The lack of snow and snow cover directly impacts the hydrology of the Sierra Nevada Mountains and thus all the flora of the various ecosystems in the Sierra Nevada Mountains. Snow levels have been steadily rising over the last 40 years, and the amount of snow lingering into the summer is declining. Due partly to the changes taking place in regards to rising snow levels profound ecosystem shifts are taking place in the Sierra Mountains. Much of the native flora is adjusting to these changes, however in time, vulnerable species may be lost.



Ranunculus occidentalis var. occidentalis is a very common perennial species in the Blue Oak Savannah ecosystem. This species emerges quickly as the late autumn precipitation season begins and temperatures cool.



Forms of Ranunculus occidentalis var. occidentalis with maroon markings on the upper leaf surface are not unusual. This is an attractive characteristic of this species. I am always on the lookout for plants with desirable variations of this characteristic.



Primula hendersonii is generally found in somewhat shaded locations. This species is among the first species to bloom in the early spring.

[Robert]

Our native annual, Claytonia perfoliata ssp. perfoliata, is commonly found in moist, semi-shaded sites. The species is edible and is now commonly sold as a vegetable by seed companies in the U.S.A.  [Jasmin:  It is sweet and nutty in flavor, and very tender.]



Gold-back Fern, Pentagramma triangularis ssp. triangularis, is often found around rocks and boulders in shaded locations. It is a xeric species that receives little or no moisture during the dry summer and autumn season.



The nascent inflorescences of White-leaf Manzanita, Arctostaphylos viscida ssp. viscida, open throughout the winter months and provide nectar for our native Anna’s Hummingbirds as well as other native wildlife species. In the winter, Pipevine Swallowtail butterflies can sometimes be seen feeding on the nectar of the flowers especially if Aristolochia californica, California Pipevine, is growing in the vicinity.
 


Toyon, Heteromeles arbutifolia, is a shrubby evergreen species commonly found in low elevation chaparral ecosystems. In the late spring this species produces large clusters of small white flowers, followed in the autumn by bright red fruit. In California, there is a yellow-fruited form of this species in the commercial nursery trade. The berries are a food source for wildlife during the winter months.  [Jasmin:  The white flowers attract ants and tiny native bees.  They smell of a nice, soft, ripened cheese—the kinds that are not available here.  I suppose the scent of these flowers is compensation?]



Rock Shield Lichen, Xanthoparmelia sp., are quite common on exposed rocks in the lower foothills of the Sierra Nevada Mountains. The species pictured could be Xanthoparmelia lineola, however I have not tested it to confirm its identity. Many lichen species are native to our region. They are extremely fascinating and variable is appearance.

[Jeffnz]

What are the tube like protrusions on the licehn?

[Robert]

Hi Jeff,

The structures you describe are the fruiting bodies of lichen, ascomata. The type of ascomata associated with the genus Xanthoparmelia are referred to as apothecia. Apothecia are generally disc or cup shaped and sit atop the lichen's surface.

[Jeffnz]

Thanks not mycology focused.
Cheers