General Subjects > Blogs and Diaries
Plants, Ecosystems, Climate - Northern California 2023
Robert:
Precipitation has been well above average this year and our local, sufficiently intact, viable natural ecosystems are responding with an explosion of wildflowers. The exuberance of wildflowers is quite apparent on our Placerville, California property.
Our Placerville property can be best classified as a Blue Oak (Quercus douglasii) Savannah ecosystem located in the Upper Sonoran Life Zone. It is situated on an east-facing slope with a dominant serpentine-based soil. These factors--together with climate--influence the mix of plants species found on our property.
Pictured above is a typical springtime scene on our property. The grassland is completely dominated by invasive species. Avena fatua hybrids (Wild Oats), Bromus diandrus (Ripgut Brome), Bromus sterilis (Poverty Brome), Hordeum murinum ssp. murinum (Wild Barley), and Poa bulbosa ssp. vivipara are the most prominent of the invasive grass species. Poa bulbosa ssp. vivipara is a relative newcomer and has proven to be especially troublesome. This noxious species was accidentally introduced on my father’s golf shoe cleats back in the 1980’s and has now spread throughout our property and beyond.
Despite the predominance of invasive grasses and dicots, we still have many native wildflowers. Dipterostemon capitatus ssp. capitatus is quite common and frequently forms large drifts on our property.
The light blue forms of Dipterostemon capitatus ssp. capitatus are most frequently seen on our property.
Although the light blue forms of Dipterostemon capitatus ssp. capitatus may be the dominant form on our property, there is a fair amount of genetic variability in the flower color. I found this white form of Dipterostemon capitatus ssp. capitatus growing on the back portion of our property. White forms of this species are not uncommon, but still not frequently seen. I also found some deep blue forms of this species on another part of our property. These are less common. Several years ago I observed a bicolored (pink and blue) chimera of this species. Sadly, a gopher ate the bulb before I could dig it from the ground.
On other portions of our property where the soil can be quite wet, there are large drifts of Ranunculus occidentalis var. occidentalis in full bloom.
Robert:
In some locations Ranunculus occidentalis var. occidentalis and Dipterostemon capitatus ssp. capitatus intermingle with each other creating a delightful combination of colors.
The small flowered annual Lupinus bicolor grows abundantly on our property.
In this scene, Common Fiddleneck, Amsinkia menziesii, is intermingling with Lupinus bicolor.
The perennial Sanicula bipinnatifida prefers semi-shade locations. Pictured is the much more common purple flowered form.
Less common is the Yellow form of Sancula bipinnatifida. The yellow form of Sanicula bipinnatifida can be confused with Sanicula graveolens; however I have never observed this particular Sanicula species on our property. Sanicula crassicaulis and Sanicula bipinnata are two other Sanicula species that grow on our property. The foliage of Sanicula bipinnata is scented like Cilantro and is very pleasant.
Robert:
I am not sure how the perennial Eschscholzia californica arrived on our property, as this species is not generally seen in our area. Much more common in our area is the annual Foothill Poppy, Eschschlzia caespitosa. Less common in our immediate area is the annual Frying Pan Poppy, Eschscholzia lobbii.
I will end with this scene with Amsinkia menziesii and Lupinus bicolor.
Robert:
Yesterday, 8 May 2023, I was able to visit part of the Caldor Fire burn scar area. The site was in the Camp Creek watershed, parts of which were severally impacted by the Caldor Fire. I was very successful accessing some key sites that I have been studying since the 1990’s. I have plenty of field notes and photographs to share. I believe much of the information will be of relevant horticultural interest.
Pictured above is Diplacus kelloggii as seen on this field outing.
Robert:
During the summer and autumn of 2021 the Caldor Fire burned 347 square miles (898 sq. km) of forestland in El Dorado, Amador, and Alpine Counties, California. It was the most destructive fire in this region and one of the most destructive fires in California history. Two-thirds of the hamlet of Grizzly Flats was completely destroyed as well as many cabins and historical sites along Highway 50, the major east-west route through the Sierra Nevada Mountains in this region. The watersheds of the South Fork of the American River and Camp Creek, which provide vital drinking and agricultural water to El Dorado County, suffered extensive damage, which will last for decades.
For most of 2022 the majority of the forestland within the burn scar region was far too dangerous for any detailed botanical survey. Extensive “salvage” logging was taking place as well as the removal of badly damaged trees near roadways and popular hiking trails.
On 8 May 2023, I had my first opportunity to do a detailed survey of a portion of the Camp Creek drainage that I have been studying for decades. I started on the northern ridge above Camp Creek at an elevation of 3,767 feet (1,148 meters), well within the Transition Life Zone of this region.
The geology of this area greatly shapes and influences the plant communities at this site. In this area, the Shoo Fly Terrane consists of Greenschists, and slates, with numerous quartz veins. The soils derived from these parent rocks is generally acidic yet quite capable of supporting healthy forest growth. Many of the quartz veins contain gold; thus there are many old abandoned gold mines in this area.
Temperatures at this elevation during the December through March time period averaged 38.75 F (3.75 C), which is 4.88 F (-2.71 C) below the 18-year average. Precipitation for this area was well above average: 48.44 inches (1,230.38 mm) is the 18-year seasonal average for this area; 72.10 inches (1,831.34 mm) have been recorded so far to date for the 2022-23 precipitation season. This is 161.38% of average to date. Snow cover during the winter and early spring months greatly influences the behavior of the plants and plant communities at this site. I recorded over 101 snow cover days in this area during this precipitation season, a number not seen in decades.
My first impression is the forest plant community appears to have benefited greatly from the fire. The complete area at this site that I have studied extensively in the past burned during the Caldor Fire. Despite the fact that this entire site suffered fire damage, the majority of the forest canopy of coniferous trees remained intact and alive. As a result of the fire, most of the under growth of shrubs and young trees was burned to the ground. The lack of dense shrubby competition has lead to the proliferation of both perennial and annual species on the forest floor.
Many shrubby species are capable of stump sprouting after their tops have been burned away by fire. Regrowth of Indian Manzanita (Arctostaphylos mewukka ssp. mewukka) and Deerbrush (Ceanthus integerrimus var. macrothyrsus) were the most commonly observed species showing strong regrowth on this outing; however, many tree species such as Canyon Live Oak (Quercus chrysolepis), and California Black Oak (Querucus kelloggii) showed healthy basal regrowth.
Viola lobata ssp. lobata was one of many perennial species that benefited greatly from the release of nutrients and additional light provided by the fire. Under the intact forest canopy I observed many blooming plants on this outing.
Viola sheltonii grows abundantly at this site. It is a shade loving species that enjoys growing in summer-dry areas under the forest canopy. The lush plants are summer dormant and completely disappear during the dry summer and autumn months. The yellow flowers of this species are very attractive; however this species blooms very early in the season. I found many developing seed capsules, but no developing flower buds or flowers.
Primula (Dodecatheon) hendersonii is quite at home growing under the high open shade of the coniferous forest canopy. Primula hendersonii exhibits considerable phenotype genetic variation throughout its range in our region. Ecotypes are not unusual. The higher elevation forms bloom considerably later in the season--even in cultivation--and have a very distinctive low, squat habit of growth. Cultivated plants grown from seed at this site bloom later than the low elevation forms of this species yet before the higher elevation forms. Both the high elevations forms and Transition Zone forms of this species are very fertile. Lower elevation forms of this species are frequently sterile or nearly so. One hypothesis regarding the sterility of low elevation forms of this species is that they may be derived from triploid hybrids with Primula clevelandii. Additional research is needed.
As I moved down the ridge into shadier sites, colonies of Asarum hartwegii started to appear. The new growth of this evergreen species was well developed at this time and was very attractive. I did not spot any developing flowers. This seemed unusual, so I hope to follow up on this observation.
Along this section of the canyon, there are numerous small seasonal water drainages and small perennial creeks. In past years I have always recorded Trillium angustipetalum at these sites. I put in considerable effort to find them, however they seemed to have all vanished. Are they emerging late this season? Did the fire somehow adversely impact them? These are all issues that I would like to resolve.
To be continued….
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