Alpine View Point – Field research: impact of frequent fire on chaparral

Being inspired to discover the truth can come from many directions.

Our current field research study has been stimulated by a recent claim that frequent fire had not harmed a particular patch of chaparral we are very familiar with – below the history-rich Alpine View Point overlook off Interstate Highway 8 in San Diego County. Our motivation recalls Thomas C. Chamberlin’s insightful paper back in 1890. He wrote,

“To be sure, truth may be brought forth by an investigator dominated by a false ruling idea. His very errors may indeed stimulate investigation on the part of others.”
– Thomas C. Chamberlin,  1890

So alas, down into the canyon we plunged this past weekend, with GPS gear, 50 meter tapes, recording journals, and a lot of water.

Looking north at the Alpine View overlook off Interstate Highway 8 from across Sweetwater River canyon. Photo taken 4/2006.

Briefly, this area has been impacted by three fires as shown in the figure below: 1970, 2001, and 2003. We wanted to determine the difference in biodiversity between the 2001 Viejas Fire area and the area that burned again in 2003.

Fire overlap areas shown below the Alpine View overlook. Photo taken 11/2013.

We ran six, 50 meter transects, three in each study area, and recorded the cover and species directly under the transect tape line. We also recorded the percent cover and species composition of three one-square-meter quadrants at the beginning, middle, and end of each transect. We will be returning to the site several times to collect more data.

Beginning locations of the six transects. Map image showing where the 2003 Cedar Fire (white line) burned into the 2001 Viejas Fire perimeter (red line).

It is too early to come to any definite conclusions, but from a general overview of the data, the twice-burned area had significantly more bare ground than the once burned area, suggesting that the second fire negatively impacted the area’s species composition and cover.

Transect 1 showing the typical composition of the once burned (2001) area.
Transect 4 showing the typical cover for the twice-burned (2001/2003) area.

We were tempted to hike down to the Sweetwater River during lunch as we heard its refreshing sounds filtering up through the chaparral below us. However, we knew we still had a lot of work ahead of us and needed to conserve our energy. The steep hike back up to the cars is enough to wipe out even the most experienced Chaparralian. So we were content to enjoy the occasional bit of beauty that met us along the transect lines.

A solitary silver puffs (Uropappus lindleyi) reminded us of the delicate beauty of nature.
The Sweetwater River valley looking westward in the late afternoon.

More to come.

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