Category Archives: nature|trees

Climate Change and the Southern Foxtail Pine

Windward side of a southern foxtail pine snag.

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.

How Many Tree Rings?

Fallen Jeffrey Pine in an area of downed trees located on the western end of the Vincent Tumamait Trail

I’ve run past this fallen Jeffrey Pine a number of times. It’s in an area of downed trees located on the western end of the Vincent Tumamait Trail, near Cerro Noroeste road. The trees probably fell after being killed by a fire. It’s a relatively large tree, and I’ve always wondered about its age.

A rough count of the growth rings gives an approximate age of 200 years. The tree ring sequence shows periods of fast growth, associated with above normal precipitation; and periods of slow growth, associated with drought.

Some related posts: Downed Trees Near Mt. Abel, Vincent Tumamait Trail

Ramping Down for Mt. Disappointment

Live oaks at Sage Ranch Park.

Note: The Mt. Disappointment Endurance Run is now the Angeles National Forest Trail Race.

Or should that be ramping UP for Mt. Disappointment? Anyway, started tapering for the Mt. Disappointment run next Saturday. Did the 13 mile Cheeseboro Canyon keyhole loop from the Victory Trailhead of Ahmanson Ranch yesterday, and then stretched the legs at Sage Ranch today. Both mornings were cool, with low clouds and fog — very pleasant!


Spider web
Here’s hoping for “not too hot” weather for the race. At the moment, the GFS and ECMWF weather models show a weak upper level trough moving through California in the Friday-Saturday timeframe. Such a scenario should increase the chances of “seasonable” temps for the race — which would still be quite warm, but maybe not crazy hot.

Update Friday Morning 8/07/09. Broad upper level trough over California this morning is keeping things cool. Yesterday the high recorded at Mt. Wilson was 70, and the low overnight was 48! Southern part of the trough is forecast to hang back over Southern California through Saturday, which could result in temps a little BELOW normal for the Mt. Disappointment race. We’ll see!

Related post: Mt. Disappointment 50K 2008 Notes