Accomplishing Forest Restoration with Biomass Harvesting Methods

Eagle Lake Ranger District
Lassen National Forest

Using The Past To Guide Our Future

Today most of the forested areas on the Eagle Lake Ranger District have far more trees than what historically existed. The more productive, mixed conifer, sites on the District will have upwards of 1,000 plus trees per acre; whereas, 300 trees per acre are more common on the drier, eastside pine sites. This in-growth is due to domestic livestock grazing and fire suppression, which has lead to today's stands that are characterized by tree densities that are several times higher than historic levels. The lack of a frequent fire return interval and impacts of domestic livestock grazing were discussed in the 1910 Lassen National Forest annual range report. The report stated:

"The [conifer] reproduction as stated in last season's report is very much better on areas that have been grazed heavy for twenty-five or thirty years than where there has been less grazing for a shorter length of time. The effect is so noticeable that the majority of the stockmen see it and insist that they will have to go out of business if the range is not burned over occasionally. It is very evident that most of these ranges were burned over at regular intervals for at least 60 years before the heavy grazing began, which was from fifteen to forty years ago. The result is that there is now a good seedling and sapling stand on nearly all of the timber grazing land."

EPI - Typical overstocked eastside pine stand on the District

A good example of the conifer encroachment discussed in the 1910 range report is illustrated in the following set of photographs that Dr. Alan Taylor of Pennsylvania State University has constructed within the Lassen Volcanic National Park. Lassen National Forest surrounds the Park. The original photograph was taken in the middle of the 1920's; Dr.Taylor replicated this photograph from the same locale approximately 70 years later.

Photo Comparison 1a: Original photo, 1920s, Lassen Volcanic National Park

Photo Comparison 1b: Photo above retaken in 1990s

Prior to the middle of the 1800s, the average fire return interval on the Eagle Lake Ranger District had an average of 7-15 years. The effects of this frequent fire return interval on the forests at that time were the creation of sparsely stocked, open, park- like stands similar to the early photograph below.

West Side of Crater Mountain 1915: Lassen National Forest, Eagle Lake Ranger District

The 1911-1916 Forest reconnaissance reports provide a good description of the forested landscape on the ELRD prior to timber harvest. In eastside pine areas, they described three general forest types: yellow pine flat, yellow pine slope and fir slope. In the yellow pine flat type, "yellow pine" (ponderosa and Jeffery pine) occurred in pure stands with no fir component. The conditions were very similar to the photograph above.

Yellow pine flats were characterized as having from about 5-25 trees per acre (tpa) >12" diameter breast height (dbh), with a "decided" or "great" lack of trees 6-12" dbh, and with good to excellent regeneration of seedlings.

Lasco Area 1923, Lassen Lumber & Box Company: Lassen National Forest, Eagle Lake Ranger District

Cruise data collected in 1946 from unharvested, old-growth stands on the District confirm that many of the yellow pine flats consisted of large pine trees (trees > 12" dbh). The data indicates that the average number of large trees per acre ranged from 9-42. Stand structures were similar to the photograph above.