Category Archives: nature|trees

Angeles National Forest Reforestation, the Natural Way

Area near Mt. Islip burned in the 2002 Curve Fire

The photograph above is of an area on the Pacific Crest Trail near Mt. Islip that was burned ten years ago in the 2002 Curve Fire. Here’s another photograph of an area along the PCT near Throop Peak that was also burned in the Curve Fire. These are from last weekend’s trail run.

The forest conditions are quite a bit different in each case. The Mt. Islip trees are on a cooler northeast-facing slope that was densely forested, and the Throop Peak trees are on a warmer, more open, south-facing slope. But in both cases you can see numerous pines, from small seedlings to young trees two to three feet tall.



Reforestation doesn’t happen overnight, but nature is remarkably resilient, and as long as an area is not burned too frequently, many forests are able to recover from fire with minimal intervention.

However, the process of recovery is multi-faceted and complex. It may involve varying degrees of regrowth and succession. In some cases, such as in the blast zone of Mt. St. Helens, the ecosystem has to be effectively bootstrapped, and seemingly restored from scratch.

Ultimately the mature forest that results from these processes will be comprised of an ecosystem — and vegetation — suitable for the array of climatic and other factors present at the time.

Attempts to shortcut this process are not often successful — such as the recent attempt to plant nearly one million seedlings in the Station Fire burn area. An Angeles National Forest official is quoted in an April 7, 2012 Los Angeles Times story as saying, “When we planted seedlings, conditions were ideal in terms of soil composition and temperature, rainfall and weather trends.” Beyond the criticisms outlined in the story did anyone in the Forest Service consider that La Nina conditions were present, and there was a good chance La Nina conditions would be present during the 2011-2012 rain season — along with a likelihood of below normal precipitation?

Tree 75

Valley oak at Ahmanson Ranch killed by 2005 Topanga Fire

The collapsed tree above is number 75 of 80 dead oaks counted on a 7.5 mile loop encompassing much of Ahmanson Ranch. The trees were burned in the 2005 Topanga Fire. Most of the trees were valley oaks, but some coast live oaks were also burned.

Most of the oaks in the Ahmanson Ranch area survived the fire, but perhaps as many as one in 20 trees were killed or severely injured. Of those that were severely burned, a small number, such as the valley oak above, attempted to replace its foliage through the process of epicormic sprouting.

Oaks that lost all of their foliage generally survived in proportion to the number of epicormic sprouts they were able to produce. Those that produced only a few epicormic sprouts generally succumbed after 3-4 years. Oaks with numerous epicormic sprouts generally survived.

Although Tree 75 didn’t make it, most of the surrounding trees survived the fire. And if you look next to Tree 75 you’ll see that its progeny, a young valley oak, appears to be doing well.

The Color of Rain III

Rain brings out the richness of the chaparral, enlivening its inhabitants, enhancing its colors, and enriching its fragrances. But in recent weeks rain storms have been few and rainfall far below normal.

The 2011-2012 rain season started out well enough. Thanksgiving Day the water year rainfall total for Downtown Los Angeles (USC) was about an inch above normal. But between Thanksgiving and Christmas the drier weather often associated with La Nina conditions became predominant, and water year totals dropped to about normal.

Northern and Central California were actually much drier than would be expected during a La Nina. Mammoth Mountain recorded no new snow between December 5 and January 19 — about a month and a half! Our dry spell was nearly as long. Downtown Los Angeles recorded no measurable rain between December 17 and January 21.

The storms Saturday and Monday added about 1.3 inches of rain, boosting the water year rainfall total to 5.06 inches. As of yesterday this was 1.87 inches below normal and about 73% of the normal total.

The problem is this time of year we fall behind another 0.12 to 0.15 inch every day that it doesn’t rain. The deficit adds up quickly and if — as the medium range models currently project — we don’t get any rain for the next 10 days we’ll down another inch and at about 64% of normal. We’ll see!

The photograph of the Ceanothus trunk is from last Sunday’s Will Rogers – Temescal loop trail run.

Related posts: The Color of Rain II, The Color of Rain