SCV Outdoor Report: Aliso Canyon
By Wendy Langhans
While I was grading theology papers the other day, I came across a questionable statement, “rebirth is always progressive”. I smiled to myself as two pictures came into my mind, pictures that were taken last Saturday in Aliso Canyon, documenting the rebirth that was occurring in the aftermath of last year’s destructive Station Fire.
Was this rebirth in Aliso Canyon progressive or restorative, an improvement or a repair? What, exactly, was going on in Aliso Canyon?
Aliso Canyon, part of the Santa Clara River watershed
A close-up view of Fremont Phacelia
The site was Aliso Creek, a tributary headwater of the Santa Clara River. The flowers are Fremont Phacelia, a native wildflower which is found growing in the sandy or gravely soil north of the San Gabriel Mountains. Their abundant growth during the first spring after the Station fire is an example of what fire ecologist describe as a “frequent fire follower”, an annual plant whose seed germination is enhanced by fire.
How can a fire enhance seed germination? There are four possibilities: exposure to (1) heat, (2) smoke, (3) scarification (abrasion of the seed's coating), (4) charcoal ash chemical signals, or some combination of the above.
Once the seeds have germinated, what other factors will lead to abundant growth? As any home gardener can tell you, it’s the same factors that will produce a bumper crop of tomatoes: sunlight, water, and fertilizer. After last year’s fire, the shady canopy was removed, exposing the ground to more sunlight. The soil was enriched by ash, which came from nearby plants or was washed doawnslope in the winter rains. Ash serves as a fertilizer, containing calcium, phosphorus, potash and magnesium. Add to this the nitrogen from nitrogen-fixing bacteria on the root nodes and you have the makings of a rebirth - a carpet of blooms.
But is this rebirth progressive or restorative? At first glance, it certainly seems like a progressive change - from death to life. But an equally strong argument can be made that it was restorative, especially when you consider it in context of a periodically re-occurring fire regime. So perhaps it’s both - and what you see depends, in part, on your time horizon.
Upcoming Outdoor Events:
Saturday, May 15, 8-10 AM. Early morning bird hike at Towsley Canyon. It’s an easy 1 mile walk and beginning birders are welcome. For map, click here.
Saturday, May 22, 9-11 AM. Native American Plant Use. Towsley Canyon. Our native California plants provide a bounty for native peoples. For map, click here.
Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at firstname.lastname@example.org for time and place.
Wednesday mornings, May 12, 19 & 26.
Saturday mornings, May 8 & 22
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.