Plants, Ecosystems, Climate – Northern California

[Robert]

Trond,

The first band of rain showers arrived in our area early this morning, 12/12. The bulk of the heavy precipitation and cold air is still offshore. When I checked the 12 Z, 500 mb map of the Northern Pacific Ocean this morning there was a large low at 56 N – 139 W with very cold air advection directed toward California. It looks like the US – NWS forecast for our region is going to be spot on: a great deal of precipitation, very low elevation snow levels, and large or huge snow accumulations in the Sierra Nevada Mountains. A large snow pack--with high liquid equivalent values that linger late into the spring season--are essential to our regional water security. Climatic change is altering this pattern.

Here are the current snow totals for selected locations within my study area as of 0 Z yesterday. I will keep the forum posted as to the changes that the current storm system brings to our area.

Site 1 > 8,275 ft.  - 2,522 meters
Snow Depth 9.61 inches – 24.41 cm
Current Liquid Equivalents 12/11 = 1.58 inches (4.01 cm) - 3 year average 13.30 inches (33.78 cm) 11.9% of 3-year average.

Site 2 > 6,750 ft. - 2,057 meters
Snow Depth 5.20 inches – 13.21 cm
Current Liquid Equivalents 12/11 = 1.14 inches (2.90 cm)  - 17 year average 5.34 inches (13.56 cm) 21.3% of 17-year average.


Site 3 > 5,275 ft. - 1,608 meters – 9.32 cm
Snow Depth 3.67 inches - 9.32 cm
Current Liquid Equivalents 12/11 = 0.51 inches (1.30 cm) - 13 year average = 0.91 inches (2.31 cm) 11.9% of 13 year average.

Site 4 > 3,450 ft. – 1,052 meters
Snow Depth 0.00 inches – 0.00 cm
Current Liquid Equivalents 12/11 = 0.00 inches - 3 year average 0.00 inches.

We grow many species of Cyclamen in containers where they are allowed to seed out in the container. The best-of-the-best [Robert’s thinking] are planted out in the garden for further evaluation. Cyclamen hederifolium and Cyclamen coum are the easiest species in the open; however other species are doing well too. Both Cyclamen hederifolium and Cyclamen coum seed freely in our garden. Here too I am selecting, often isolating distinct lines for further development of specific traits. It is great fun and the Cyclamen add a great deal of interest to our garden for much of the season. Our gardening goal is a beautiful garden, an earthy paradise to enjoy.

[Robert]

The recent series of storms have exited our region. Current snow depths have improved dramatically. Above is a snow depth chart from a site at 6,700 feet (2,042 meters) in the Crystal Range of the Sierra Nevada Mountains. The blue line is last season’s snow depth, a very dry precipitation year. The red line is the snow depth as of today, 18 December 2021.



Snow liquid equivalents provide another perspective on our current precipitation season. The blue dashed line is the 17 year average. The dotted red line is last year’s totals. The solid red line is this season’s total to date. We are currently above average; however we still need more to build a large snow pack to provide water for both managed and unmanaged ecosystems during the dry summer and autumn seasons.

Snow cover or its absence impacts many plant biological processes. In some instances and circumstances, photoinhibition can severely affect plant biological possesses or cause death. Conifers in alpine or subarctic habitats are well adapted to deal with the combination of extremely low temperatures with periods of high light intensity.  This is also true of evergreen alpine and arctic/subarctic plant species. However, in other instances, evergreen and newly emerging herbaceous perennial species need to adjust to cold temperatures and high light intensities to cope with the stresses of photoinhibition. A sudden abrupt end to snow-cover during winter or early spring, when temperatures can still be extremely cold, can create conditions where the excess flow of electrons from photosystem II light-harvesting complexes can overwhelm a plant’s ability to quench or redirect the flow of energy, causing destruction of exposed tissues, or in severe instances, death to the plant. I wonder if photoinhibition is an overlooked source of cultural difficulties when attempting to grow alpine species well beyond their normal range of growing conditions.

In my next posting I will give some examples.

[Hoy]

Robert,

I hope you'll get a lot more snow!

After a very cold period we have had a mild period with up to 8-10C here at the coast. Even the mountains have had above freezing for some days. But now we will get a new inflow of cold Siberian air and the temperature will drop below freezing again.

As we have no permanent snow cover (the snow disappeared quickly when the mild weather arrived) the plants have to withstand cycles of freezing and thawing. Not all plants tolerate that! Next week we will get temperatures down to -5C probably without snow. I don't like it!

[Robert]

Photoinhibition continued…

I am writing about photoinhibition in a broad sense. To the best of my knowledge, both prokaryotes (e.g. cyanobacteria) and eukaryotes (e.g. any plant species) species that carry out the photoactive portion of photosynthesis using photosystem II light-harvesting complexes continually need to repair and replace damaged photosystem II complexes, due to photoinhibition during periods when they are exposed to light.  Liken it to our bodies replacing damaged cells and tissues, such as when our skin becomes sunburned.

Plants have evolved multiple methods to diminish the impacts of photoinhibition, and partially protect sensitive biological systems.  Under certain circumstances, these protective processes become overwhelmed, and tissue damage and death of the plant can ensue.  My definition of photoinhibition in a broader sense is the many processes to reduce the impacts of photoinhibition.

In my previous posting, I wrote about how conifers and perennial alpine species have evolved protective processes to channel excessive potentially damaging energy away from sensitive biological structures.  In addition, plants have evolved morphological adaptations, such as leaves that are held perpendicular (rosette structure, etc.) to the most intense mid-day sun, and glaucus, gray foliage that increases albedo.  Biological adaptations, such as the ability to adjust the ratio of photosystem I and photosystem II light-harvesting complexes based on light intensity, and the adjustment of the position and arrangement of chloroplasts/thylakoids within the plant’s cells, help plants ameliorate the potential excessive overload of energy to other biological structures within the plant.

This returns us to the question if photoinhibition contributes to some cultural challenges faced when growing alpine species well beyond the parameters of their native habitats.  Observations, based on my studies in the Sierra Nevada Mountains, suggest that under specific conditions certain alpine species can be impacted by photoinhibition (overload of excessive energy that cannot be processed quickly by other downstream biological processes).  During conditions where protective snow cover is abruptly missing during the mid-winter months, in conjunction with extremely low temperatures, appears to impact vulnerable species.

While my ultimate goal is to have a beautiful garden, I enjoy this type of research and development.  I like to find ways to bring a broader selection of plants into permanent cultivation in our garden.  Too many fine species have been transient in our garden.  They have been extremely difficult to maintain, and are now gone.  We know we are not the only gardeners to have this experience.  Our propensity for seeds and plants from other regions is perhaps our shared longing to bring the wider world into our gardens, especially when travel is prohibitive.  In my case, it is being able to bring some of the mountains I have loved my whole life to our home.  Creating an easy-to-grow version of Viola purpurea will only occur through creative innovation.  There are so many additional possibilities.


Trond,

More precipitation is forecasted for us during the coming week.  There are also hints that this wet pattern will persist into the new year. This is great news for us. Currently, our precipitation totals have already exceeded last season’s totals for the whole year.  I will be posting more on this topic as events unfold.

[Hoy]

Photoinhibition is an interesting topic. Much has been written since I was a student! My wife worked with photorespiration in her degree. (I worked with genetics.) However I think plants in your part of the world are more affected by high light levels in winter than plants up here.

YR tells you will get rain almost every day this week!

https://www.yr.no/nb/værvarsel/daglig-tabell/2-5389489/USA/California/Sacramento/Sacramento

[Robert]

Trond,

Yes, I agree. Plant genetics, photorespiration, photoinhibition, etc. are all interesting topics. Clearly, I am attempting to simplify my discussion of these topics, explain how I apply these concepts into my gardening activities, and share my results (both the failures and successes). Growing exotic species from habitats that are incongruent to our growing conditions has never worked well for me. Many of our local California native species have never been fully studied or their horticultural potentials fully explored. This is enough to keep be busy for many lifetimes. Each day in the garden brings something new. Molding our garden into a tapestry of beauty is such a pleasure.

When caregiving ended last year I thought that I would end up “retired”. This has not turned out to be the case at all. Avenues of plant/habitat/ecological research and other closely related projects have opened up for me. Who wants to retire when life can be so fascinating? In this diary I am attempting to blend aspects of my work with gardening/horticulture. Maybe this is of no interest to the reader of the forum (no rare, exotic plants here). I enjoy exploring deeper into the workings of the most common plant species and discovering the yet hidden potentials they contain. This is my approach to garden. Others have their approach. It is all good. We can benefit and learn from other perspectives - to create fascinating gardens for us and bring something good to this planet.

I will have updated weather information as I can. We need the rain and snow in the Sierra Nevada Mountains.

[Hoy]

Robert,

It is interesting to read about your efforts. Although you say you have noe exotics, you have! Your more or less common native plants are exotic to most of us. I for example, like to try our native plants in my "gardens" but but we have very few native plants here in Norway compared to S. Europe, N. America etc. Therefore I like to try exotics in my garden!

Here is photograph of a native plant I grow at the shed roof in my garden at home, Thalictrum alpinum. It is not uncommon in the mountains though.

[Leena]

Your more or less common native plants are exotic to most of us. I for example, like to try our native plants in my "gardens" but but we have very few native plants here in Norway compared to S. Europe, N. America etc. Therefore I like to try exotics in my garden!

I feel just the same. There are so few garden worthy native plants, and also the variation within a species is very little. I am always amazed how much variation there is in plants in North America and also in other countries, like Corydalis is Russia. Here Corydalis solida comes only in one colour and form. It is probably because there was only a "little" time for them to develop here after the last ice age.

[Robert]

December 2021 is turning out to be the snowiest in 50 years. We started the month of December with, more or less, no snow in the Sierra Nevada Mountains. Temperatures were well above average for the first 7 days of December, and then the weather pattern began to make a dramatic shift. For most of November and the first week of December, the Walker Circulation pattern was in a typical La Niña pattern with convection along 120 to 125 E longitude. This pattern brought abundant precipitation to the Pacific Northwestern portion of North America. Here in California the weather was sunny and extremely dry, with above average temperatures. By 9 November a very strong region of convection developed along 140 E longitude. Our temperatures began to cool and the storm track shifted, bringing cold low-pressure weather systems out of the Gulf of Alaska into California. By 18 December an Omega blocking high-pressure system started to develop in the Northern Pacific Ocean. We were on the eastern (wet) side of this Omega blocking high pressure. One after another, cold Gulf of Alaska weather systems tracked through our portion of California bringing abundant snowfall to the Sierra Nevada Mountains and, at times, very low snow levels. [So far nothing at our Sacramento home.  We had to make sure the pipes were covered in Sacramento, and covered and drained at the property in Placerville.  Currently, it is at the border between rain and snow.  Not much further up the road, it was a complete traffic standstill in heavy wet snow.  Returning home yesterday was hazardous with several heavy downpours.  If the air had been just a few degrees colder, it would have halted us completely in heavy wet snow.]



As one can see from this chart, the snow depth at 8,600 feet (2,621 meters) in the Crystal Range is well above any level achieved during the 2020-2021 season. Red line 2021 to date, blue line 2020-2021 season.



Examining the snow liquid equivalents for the same site one can see that we are well above average to date, but still need a great deal of snow to have an average snow pack for the current season (in other words, our drought conditions have not ended yet).



At times a great deal of snow fell at lower elevations in the Sierra Nevada Mountains. This local site at an elevation of 3,625 feet (1,105 meters) currently has over 65 cm of snow on the ground. This is well above any snow depth seen in many years.

Although the current Pacific Ocean equatorial SSTs are indicative of a strong La Niña event, the current weather and atmospheric pattern is not what I usually associate with La Niña. For example, currently the Trade Winds in the Central Pacific are weak. In addition, a strong convection center at 140 E longitude is more suggestive of an El Niño type pattern. Where will the weather turn from here? Very cold temperatures are forecasted in our region into the New Year: nothing extreme, but much colder than anything we have experienced in many years; although it is very much like what we once regularly lived with. The big question is, will the weather continue in the current atypical cold, wet pattern or will the typical dry La Niña pattern return to our portion of California.

Stay tuned…

[Robert]

With an average temperature of 61.03 F (16.13 C), the year 2021 tied 1986 and 1987 as the third warmest year on record since 1983 when consistent weather records started at our Placerville, California property.



The summer of 2021, June through September, with an average temperature of 76.30 F (24.61 C) was the second warmest on record since the brutal summer of 1984 (76.53 F, 24.74 C).

Atmospheric variables such as temperature, precipitation, solar radiation (cloud cover, etc.) and more have such an impact on both managed (farms and gardens) and unmanaged ecosystems (wild habitats). I carefully observe and compile data on how changing weather and longer-term climatic changes impact individual plant species as well as ecosystems as a whole.



Atmospheric teleconnections have a major impact on our weather, and thus our gardens. The current La Niña has been unusual in that there have been periods of time when the Trade Winds in the Central Pacific Ocean have been very weak (very un-La Niña like). During both instances we experienced well above average precipitation in our portion of California. The late October atmospheric river that impacted California occurred during the annual shift in the difference between continental and surface sea temperatures (relatively warm continental temperatures vs. relatively cooler surface sea temperatures shift to the opposite pattern).

The above chart shows the weekly changes in the Northern Pacific Trade Winds during the month of December 2021. The x-axis shows degrees longitude, starting on the left at 120 E to 120 W on the far right. The y-axis is Trade Wind magnitude. From slightly before mid-month to the end of the month the Trade Winds relaxed in the Central Pacific and we experienced well above average precipitation in our portion of California. The shift in the Trade Wind pattern also reflected an eastward shift in the connective pattern in the Western Pacific Ocean.

Obviously the ENSO teleconnection is complex. Rather than a simplistic flux between La Niña, Neutral, and El Niño patterns there are nuances that strongly alter the climatic outcomes.

Now that the Holiday season is over, I will soon be resuming my fieldwork in the Sierra Nevada Mountains and the Foothill regions. The strong interaction between weather, climate, plant species, and their ecosystems will be continuing topics of discussion. My goal is to provide information that will help gardeners succeed with specific plant species and create resilient garden ecosystems.

[Robert]

I am currently preparing for my first outing of the 2022 season, scheduled for this coming week. Although much of the snow below 4,000 feet (1,219 meters) has melted, I will be surveying lower elevation sites in the Upper Sonoran Life Zone region of Northern California. It has been a number of years since I have been able to work in these areas.

[Jasmin adds]: Much has changed: The pace of development has been astounding. We question the viability of the developments in these areas that were never meant to sustain human population density. The areas in question never had water access, and with the sustained drought water tables have plummeted further. The loss of habitat, of beautiful wildflowers, native oaks, and other native plants, plus the loss of habitat for wildlife is a travesty.

Our Placerville property is located in a Blue Oak Savannah, well within the Lower Sonoran Life Zone. Ranunculus occidentalis var. occidentalis, pictured above, is a very common perennial species in this Life Zone region.



Sanicula crassicaulis prefers shaded habitats. This perennial species has very interesting textured foliage.



Claytonia perfoliata is an annual species. It prefers semi-shaded moist locations. Over the years this edible species has infiltrated into commercial agriculture and is now frequently sold at markets, generally as one component of a salad mix.

[Jasmin adds]: It has a delightful, lightly sweet, refreshing flavor. It is very tender, like butterhead lettuce when young, but still quite tender when mature, unlike regular lettuce which can become tough. It also never develops the bitter flavors lettuce can.



Primula (Dodecatheon) hendersonii has emerged from the ground. There are a number of interesting forms and a few ecotypes of this species.



Non-native, invasive species are now a large component of the lower Life Zones throughout California. In this photograph, Trifolium hirtum can be seen on the right, and the partly dissected leaves of Geranium molle on the left. Non-native species, especially non-native grasses, have seriously impacted our lower elevation ecosystems.

[Jasmin adds]: Their vigor has outcompeted native plants, aided by the variety of human activities: Livestock favored the native plants, consuming them nearly to oblivion, and excreting and otherwise spreading invasives; agricultural activity stripped the land, and the invasives thrive in disturbed areas; development adds to this burden, and no space is left for native plants or animals. The invasive plants life cycles are enhanced in these environments: Rapid growth is followed by early seeding and spreading, concluding with dying back to a very tinder-dry grass that ignites at the least opportunity. These are the very hot fires that are so devastating in California for all life forms.  Although many native plants do survive and thrive, often coexisting with fire—many do need fire to germinate and survive—they are unable to propagate themselves in this environment. It really is a miracle we have any native plants at all.

[Robert]

Micranthes californica is not native to our Placerville property; however it is native to other local sites within the Lower Sonoran Life Zone. For better or worse, I introduced these plants over 10 years ago. They continue to persist, blooming each season. Despite their persistence, they have not found an available niche where they can propagate and spread on our property.



For many years, I have been attempting to reintroduce native species that likely grew on this site in the past. Heteromeles arbutifolia has been successfully reintroduced to the property and new plants appear here and there each season.



By the means of animal scat, birds, or the wind, other species have started to recolonize our property. Pictured is White-leaf Manzanita, Arctostaphylos viscida ssp. viscida. This species is fire dependent for seed germination. After a fire this species will germinate prolifically; however this species is clearly not 100% dependent on fire for seed germination. I have seen plants germinating from scat and bird droppings.



The Blue Oak, Quercus douglasii, pictured center, has retained many of its leaves from the previous growing season. This is unusual for this species and is an indication of extreme drought stress. The extreme drought our region has been experiencing over the past 20 years is seriously impacting the ecology of our region. Many trees have died (see background, right side). In addition, regeneration through seed has slowed or shifted with many species.



A closer view of the drought-stressed Blue Oak, Quecus douglasii.

Until the next time…

[fermi de Sousa]

Claytonia perfoliata is an annual species. It prefers semi-shaded moist locations. Over the years this edible species has infiltrated into commercial agriculture and is now frequently sold at markets, generally as one component of a salad mix.

[Jasmin adds]: It has a delightful, lightly sweet, refreshing flavor. It is very tender, like butterhead lettuce when young, but still quite tender when mature, unlike regular lettuce which can become tough. It also never develops the bitter flavors lettuce can.

Hi Robert and Jasmin,
it's called "Miner's Lettuce" here and has become a minor pest in my pots! I think a single seedling appeared in a potted plant of something else a number of years ago and has spread around since. I have to admit though I know that it's edible I haven't actually tried it! Maybe next spring,
cheers
fermi

[Robert]

Hi Fermi,

Here in California, Claytonia perfoliata is also called Miner’s Lettuce. It is quite good. We eat it all the time! Up at the Placerville property it is a naturally occurring native plant. It also grows at our Sacramento home, however the seeds traveled from Placerville to Sacramento in pots. It most likely grew here at our Sacramento home in the very distant past. However, the native flora was removed from the area around our Sacramento home so long ago it is impossible to determine with certainty if this species grew near our Sacramento home.



I had a very productive outing yesterday in an Upper Sonoran ecological habitat. I will report on this outing over the next week to 10 days.

[Robert]

I started this outing at a very familiar site in the Upper Sonoran life zone of Northern California. Although much of the area I surveyed on this outing was at an elevation of  ~ 500 feet (152.4 meters)--an elevation generally associated with the Lower Sonoran Life Zone--a ridge of tall hills separated this area from the Central Valley and its Lower Sonoran Life Zone to the west.

A pair of old and very familiar Western Redbuds, Cercis occidentalis (pictured), greeted me as I arrived at this site. I first visited this site during the early 1970’s when I was in High School. It was a great place to spend summer evenings swimming and fishing. Later in the 1970’s our college Native Plant Identification class held a field trip to this site. It was during this field trip that I came to appreciate the botanical significance of this area.



This site consists of areas of dense chaparral (pictured) and areas of Blue Oak (Quercus dougasii) woodland and savannah. Our Northern Californian Upper Sonoran chaparral habitat has a very distinct scent due to the mixture of the many aromatic plant species that occupy this ecological life zone.



California Gray Pine, Pinus sabiniana, is a very common species in this area. This species has very large pinecones, something that you want to avoid having fall on your head!



Salvia sonomensis is a chaparral species. This mat-forming species is frequently seen growing under and around the taller-growing chaparral shrubbery.



The foliage of Salvia sonomensis has a very strong and delightful scent. On a warm summer day the scent of this species fills the air, mixing with the scents of the other chaparral plants.