A closer look at one of several developing yucca stalks found on the warm, south-facing slopes of the Burkhart Trail.

From last Sunday's run on the PCT and Burkhart Trail in the San Gabriel Mountains.

From a run this week on the Secret Trail in Calabasas, California.

A high contrast study of the twists and turns of the disintegrating bole of a lodgepole pine on the slopes of Charlton Peak.

From the 26 mile San Gorgonio High Line trail run a couple of weeks ago.

From a run at Ahmanson Ranch earlier this week.

Also from Sunday's run on the Backbone Trail in the Santa Monica Mountains.

The windward side of this foxtail pine snag has been blasted by the icy winds of a multitude of Winter storms. The wind has sculpted the mineral-like wood, exposing and accentuating its inner layers.

The photo is from last Saturday's Cottonwood Pass - New Army Pass trail run. Nearly all of this route is above 10,000 ft. and 12 miles of it are above 11,000 ft. This relatively dry, high altitude habitat is home to the southern foxtail pine (Pinus balfouriana subsp. austrina).

One of the less common Sierra conifers, the tree is a long-lived species that is closely related to the bristlecone pine. The FEIS database references a southern foxtail pine 3400 years old, and the Gymnosperm Database a specimen with a crossdated age of 2110 years.

Because the tree grows so slowly, the wood is dense, and dead trees are slow to decay. In the vicinity of Cirque Peak, and a few other areas, dead foxtail pines and remnants are found above the current tree line. By crossdating tree ring sequences, a study published in 1997 found that over the past 3500 years the tree line in this part of the Sierra has generally been higher than it is now.

The study deduced that one period of reduced tree abundance and lowered tree line elevation was associated with warmer temperatures, and at least two severe multi-decade droughts. In contrast, the most recent decline has occurred during a cold, wet period that started about 450 BP.

It is remarkable that some of the dead foxtail pines studied here were alive during the Bronze Age, 4000 years BP.

As found on Sunday's run at Sage Ranch Park.

From Sunday's hike/run up and down Mt. Baldy's South Ridge.

Study of a mushroom-like arrangement of newly sprouted Big Leaf Maple Leaves. From Sunday's Red Box - Bear Canyon trail run.

Study of color, form, and texture in decomposing wood. From Sunday's Red Box - Bear Canyon trail run.

Macro still life of Douglas' nightshade at Stoney Point, a bouldering and top-rope climbing area in Chatsworth, California, northwest of Los Angeles.

From Sunday's run of the Will Rogers - Temescal loop.

Related posts: Spring on the Bent Arrow Trail, Will Rogers - Temescal Loop

From a run to Calabasas Peak on the Secret Trail in February.

Related post: Secret Trail to Calabasas Peak

Green beneath Summer's bleached stalks, the growth of this grass at Sage Ranch reflects the near normal rain season we've had to date in the Los Angeles area, and over much of Southern California. Since the start of the water year on July 1, Downtown Los Angeles (USC) has recorded 4.66 inches of rain. When this photograph was taken, January 11th, 4.66 inches was almost exactly normal rainfall for the date.

However, as is so often the case in Southern California, this apparent normality is the sum of offsetting wet and dry periods. December's precipitation was generally well above normal, but January has been dry, dry, dry. Today, the Los Angeles rainfall total is about 0.5 inch below normal, and every day it doesn't rain, our deficit increases by about 0.10 inch.

So when might it rain? A very strong 200 kt Pacific jet stream has pushed up a high pressure ridge over the West Coast, blocking storms and warming temperatures. Big upper level ridges such as this are consistent with La Nina, and have been a recurring theme this Fall and Winter. Much of our rainfall and cold weather this season has occurred when an extended Pacific jet collapses or contracts, and a blocking ridge shifts west, opening the door to cold storms plunging down the backside of the ridge from the north.

Over the next 1-2 weeks, this is expected to happen again, but this time there is a wildcard in the mix. One of the reasons the Pacific jet is so strong is the active phase of the Madden-Julian Oscillation (MJO) is present in the Western Pacific. As described in this Climate Prediction Center document, this scenario sometimes leads to a heavy West Coast precipitation event.

It's too far out for the medium range models to be of much help in assessing the likelihood of such an event developing. At the moment, about the only thing that can be said with some certainty is that a pattern change is in the works, and by the end of January there is a chance of some rain in California and the West. We'll see!

Related post: Southern California 2008-2009 Winter Precipitation Outlook, Snow on Oat Mountain

From the Boney Mountain loop a couple of weeks ago.

Fall color is not as widespread in chaparral as in some other plant communities. This vividly colored poison oak is along the Garapito Trail in Topanga State Park.

From a run of the Trippet Ranch Loop from Marvin Braude Mulholland Gateway Park at the southern end of Reseda Blvd., in the San Fernando Valley.

Related post: Poison Oak, Ferns Along the Garapito Trail

One hundred degrees
A willowed stream
Late afternoon sun
And linear green.

Study of cattail leaves in afternoon sun.

From a run to Las Virgenes Creek from the Victory trailhead of Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

Plumed achenes of curl-leaf mountain mahogany (Cercocarpus ledifolius) on the Chumash Trail. From Tuesday's run.

From Sunday's San Gabriels High Five run and hike.

From Sunday's San Gabriels High Five run and hike.

It's been late February since Southern California has had a good soaking rain. As of May 1, the water year rainfall total for Downtown Los Angeles (USC) stands at 13.42 inches. This is 90% of the 1921-2006 average of 14.87 inches. According to the NWS 1921-2006 dataset, the average amount of precipitation in May and June is 0.3 inch and 0.1 inch, respectively. We'll see if we get that much this year!

La Niña appears to be winding down. In it's April 30 ENSO Wrap-Up, the Australian Bureau of Meteorology characterizes Pacific climate patterns as being generally neutral, "with the majority of indicators returning to near-normal levels." The April 28 ENSO Update from the CPC suggests that La Niña will continue through May-July 2008, but many of the factors discussed indicate general weakening of La Niña. Based on the ONI and MEI, La Nina conditions have existed since about August of 2007.

The photograph of the sun-parched mustard leaf is from a run at Ahmanson Ranch on April 29, 2008.

Technorati Tags: la nina, Los Angeles weather

From a run at Ahmanson Ranch -- now Upper Las Virgenes Canyon Open Space Preserve.

From a late afternoon trail run along Las Virgenes Creek in late November 2007.

When I see crystals of hoar frost sparkle in the Winter sun it triggers a child-like awe. On Sunday's Condor Peak Trail Run, several sections of trail glittered as we ran into a low morning sun. On the cold east face of Fox Mountain, a fine, needle-like frost coated the edges and surfaces of leaves and twigs that had collected in pockets on the steep slope.

Digitally magnifying a small section of a 10 Mp image revealed that the frost is comprised of hollow columns, and further magnification shows that the columns are hexagonal, with lengthwise facets.

This type of frost - hollow columnar hoarfrost - is described in STUDIES OF FROST AND ICE CRYSTALS by W.A. Bentley, in the Monthly Weather Review, Volume 35, Issue 9 (September 1907), pp. 397-403. Here is an excerpt:

"When formed in the open, they are essentially mild-weather types. They are most common to early autumn and late spring, and the hoarfrost that collects upon the plants and grasses during the so-called destructive frosts at those dates is almost invariably of this type. Hoarfrost deposits of this character form in the open during calm, clear nights when the surface air temperatures range from 56 degrees to 40 degrees at nightfall, and from 33 degrees to 25 degrees during the latter part of the night or early morning."

Here is a graph of weather data recorded by the Mill Creek (ANF) RAWS on December 1 and December 2. The elevation of the station is 3510' and it is about 8.5 miles from Fox Mountain (5033'). Parameters graphed are the hourly average wind speed, air temperature, fuel temperature, relative humidity, and dew point.

At Mill Creek the fuel temperature dropped below the frost point at 10:00 p.m Saturday, and did not exceed the frost point again until 8:00 a.m Sunday. For a 5 hour period from 2:00 a.m. to 7:00 a.m. the mean air temperature was 30°F-31°F and the fuel temperature was 22°F-23°F -- suggesting strong radiative cooling. Similar conditions probably produced the frost on Fox Mountain.

From Tuesday's run at Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

From a run at Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch). Note the hawk in the tree on the left.

From a run at Sage Ranch. (A 16:9 format image.)

Study of a wall of the Electra Powerhouse on the Mokelumne River.

It's growth exhausted, this dessicated stalk of hummingbird sage (Salvia spathacea) is a relic of Southern California's 2005-2006 rain season. A robust member of the mint family, the flowering stalks typically grow to a height of 1-3 ft., but in this case the full stalk reached about 4 ft. The 2006-2007 rain season was too dry to produce flowering stalks in this area.

From a run at Sage Ranch Park on August 22, 2007.

Related post: Dealing with Drought

Who hasn't pondered the intriguing network formed by the interconnected veins of a leaf? Like many apparently complex self-organized structures, there is a recognizable pattern, but the basis of the pattern is difficult to grasp.

Remarkably, research published in 2002 (S. Bohn et al., Phys. Rev. E, June 2002.) found that there is a simple relationship governing the angles between vein segments in the leaves of dicotyledons, and that this relationship is universal. The study also found that the observed vein angles can be reproduced using a simple force model.

Numerical analysis of leaf scans revealed that the angles between vein segments are directly related to the thickness of the segments. When the vein sizes are similar, the connection appears to form a three-way junction with the angle between the veins about 120 degrees. If the vein sizes are dissimilar, with one much larger than the other, the smaller vein joins the larger at about a 90 degree angle.

The photograph is of a leaf of a Fremont cottonwood (Populus fremontii) along Las Virgenes Creek in Upper Las Virgenes Canyon Open Space Preserve. It was taken on a run from the Victory trailhead on May 16, 2007.

Taken while running the Lower Stagecoach - Hummingbird loop on July 12, 2007.

From Sunday's Cheeseboro Bound run. Exactly as found.

From Sunday's Backbone, Bulldog & Beyond run.

From a showery, twilight run in the Simi Hills.

In addition to the Chumash-Hummingbird loop, another good trail run in the Rocky Peak Park area is the Chumash-Las Llajas loop. Both loops are about 9.2 miles long, have a mix of dirt road and technical single-track trail, and include some strenuous climbs. The Chumash-Las Llajas loop has less elevation gain/loss, and if you run the loop counter-clockwise, the downhill in Las Llajas Canyon makes for a fast-paced 4 mile descent.

I like to do the loop starting at the Las Llajas Canyon trailhead on Evening Sky Dr. A short jog to the east end of Evening Sky Dr., and across a field, and you're on your way up the Chumash Trail. Here's a Google earth image and Google Earth KMZ file of a GPS trace of my usual route, and another view of part of the route from near the high point on Rocky Peak Rd. (It is also possible to start the loop at the Chumash Trail trailhead at the end of Flanagan Dr.)

At Rocky Peak Road's high point is an outcrop of fossil shells. According to the Dibblee geology map of the area, these may have been deposited in shallow marine lagoons a couple million years ago. There is a year around creek in Las Llajas Canyon, and the complex oil field geology is very different from the sandstones along the Chumash Trail and Rocky Peak Rd.

The last time I did this loop, I had run just turned off Rocky Peak Rd. and was working up toward a hilltop to an old oil field service road, when I heard the unmistakable rat-a-tat-tat of a dirt bike. Bike #1 popped over the crest of the hill, and as we passed I asked with a hand signal if there was a second bike. There was. We avoided each other and I continued over the hill and down the road.

A couple hundred yards down the road from the crest of the hill, I found this kangaroo rat. It could not have been dead for long. It was larger than I expected, and had remarkable coloration.

The photographs of the out service tanks and the kangaroo rat are from a run on November 11, 2006.

Related posts: Chumash Trail Snow, Chumash Rock, Chumash View, Oat Mountain Snow, San Fernando Valley from Rocky Peak.

Peculiar pattern in low lying manzanita on the south slopes of Pine Mountain. A friend noted the remarkable similarity of this pattern to that found in gypsum crystals in a desert rose. From the Mt. Baldy North Backbone Trail run/hike.

Brown seed stalks of Curly Dock (Rumex crispus) amid dried grasses and mustard on Laskey Mesa in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

Curly dock is a non-native invasive weed from Eurasia. The Cal-IPC Invasive Plant Inventory describes its impact as limited.

From a run at Ahmanson on September 13, 2006.

A bracket fungus (prob. Laetiporus gilbertsonii) on a burned eucalyptus in the Simi Hills.

A Chalk Liveforever (Dudleya pulverulenta) at Sage Ranch a few weeks after the 2005 Topanga Fire burned through the area. (Photograph from November 24, 2005.)

When the hills and valleys of Southern California turn golden brown, and temperatures reach into the nineties or beyond, mixed in among the desiccated grasses, enjoying the heat and the sun, may be the delicate pink to purple of a Plummer's Mariposa Lily (Calochortus plummerae).

The Plummer's Mariposa is listed by the California Native Plant Society as being rare, threatened, or endangered.

Note: Plummer's Mariposa Lily (Calochortus plummerae) and Foothill Mariposa Lily (Calochortus weedii var. intermedius) are closely related species that have intersecting ranges and similar characteristics. C. plummerae is more frequently reported in Los Angeles County.

A snow plant and other forest floor elements highlighted by a shaft of sunlight. The photo was taken on a rambling out and back run of about 25 miles from the lower McGill trailhead to Mt. Pinos and Mt. Abel on July 24, 2005.

Here's a Google Earth image and Google Earth KMZ file of a GPS trace of my route.

For additional snow plant photographs, see the posts Three Points - Mt. Waterman Loop and Snow Plant, and also Snow Plant on SierraPhotography.com.

Bear Creek is an isolated tributary of Arroyo Seco Creek, north of Pasadena, in the San Gabriel Mountains. This photo was taken on a spectacular Fall day in upper Bear Canyon on a long trail run that started at Clear Creek Station. The route worked around the north side of Strawberry Peak to Red Box, down to the West Fork, up the Valley Forge trail on Mt. Wilson to Eaton Saddle, then through the Mueller Tunnel and past San Gabriel Peak and Mt. Lowe to Tom Sloane Saddle. From here it continued down into Bear Canyon, up the Gabrieleno Trail to Switzers, and then back to Clear Creek using the Nature's Canteen trail. (Photo from November 11, 2005.)

Related post: Strawberry - Bear Canyon Loop.

Ferns along the Garapito Trail, Topanga State Park.

Chaparral has been described as an elfin forest, and there is probably no better trail in the Santa Monica Mountains to see why, than the Garapito Trail. From the fire road near Eagle Rock, the trail seemingly dives into a tunnel of chaparral, and doesn't emerge until it ends at Temescal Fire Road, some 2.5 miles away.

This day I ran a 12 mile figure-eight course from the end of Reseda to Trippet Ranch via the Hub, and then returned via the Musch, Garapito, and Bent Arrow trails. Fire roads out-- trails back. A shorter option goes directly to the Garapito Trail via the Hub, and then returns via the Bent Arrow trail. This is about 7.5 miles. A longer option tacks on an out and back to Parker Mesa at Trippet Ranch.

Snow highlights skeletal fingers of chaparral burned in the 2003 Simi Fire. From the Chumash Trail in the eastern Simi Valley. More info and a couple of additional photos can be found in my Coyote Oak Journal entry Chaparral Snow.

Fire-sculpted limbs of a Laurel Sumac in Black Canyon, near Simi Valley.