Chaparral
is a rare biome found in few places throughout the world, one of them being
southern California. Chaparral is recognized by its woody drought-hardy shrubs,
Mediterranean-like climate, and wildfires. Now, the wildfires are where the
controversy comes in. Due to the misunderstandings of the Chaparral, it is
being managed poorly and thus having greater problems. Chaparral is extremely
beneficial to California due to the essential protection it provides against
soil erosion, its moderation of climate, its underground water supplies, and
its habitat for flora and fauna. While urban sprawl is quickly dominating the
region, fire management is taking many different extremes. Some believe that
frequent fires are necessary to maintain biomass build up, while others counter
that the region should not be managed with fires at all. A burning system in
between the spectrum is the best answer. Due to the growing urbanization, fires
can no longer be completely wild and must be managed to ensure the chaparral
can maintain its sustainability. Today I will describe the California mosaic
hypothesis and another contrasting view, a brief history of the land, and
provide a quick overview of the naturally occurring flora.
The
Department of Sustainability and Environment describe the California mosaic
hypothesis as, “Applying planned fire at varying intensities, scales, and times
within a broader landscape to create patches of burnt and unburnt areas that
change over time” So, the idea is that biomass will accumulate, and, if not
managed, create a larger, hotter, and less controllable fire. However, when
chaparral is burned too often, certain plants that aren’t as tolerant to the
flame can be lost and invasive weeds can take over. It takes Chaparral about
two years before it truly flourishes with density and diversity after a fire,
and it cannot reach that potential if everything is consistently being burned
away. Poor burnings can also lead to soil erosion. On the other hand, The
California Chaparral Institute believes that fire is not necessary at all to
maintain a healthy ecosystem… but doing nothing can encourage larger out of
control fires. Allowing fires to occur naturally, or preventing them
completely, can be unsafe due to the volatile oils in the plants that allow
flames to spread to different flora easily. One of the largest factors of
uncontrolled wildfires, besides the easy combustion of the oils, is wind,
especially the Santa Ana winds which can spread fires quickly and in many
directions. The four contributors to out of control fires, and thus the at risk
concern of people and property, is heat, oxygen, fuel, and weather. Another
concern of a zero fire regime is the important flora, such as mariposa lilies
and fire poppies, that need the extreme heat or char in order to germinate as
well as fire being a key source in helping nitrogen bound in organic material
to transform into ammonium which is directly usable for flora to prosper.
And
now a brief history: Ethnographic studies support that the land was once
maintained by aboriginals who would manipulate the land with fire as a means
for better hunting opportunities, protection, and warfare strategy. Despite the
fires being more frequent than the average fire induced lightning storm, two
recorded in the past twenty-five years, they still allowed the area to thrive. Once
settlers began to migrate to southern California, though, the land was left
vulnerable to invasive European grasses. The invasive grasses can take over if
the native plants aren’t cared for properly. Frequent fires were still
practiced in the 1800’s which is when the first massive wildfire took place.
The Tujunga wildfire occurred in 1878 and became unmanageable due to the Santa
Ana winds. The second wildfire didn’t occur for another 20 years providing
evidence that wind is a larger factor than biomass buildup.
Next
I will discuss the chaparral flora. The flora in chaparral has developed
modifications to help survive during and after fires. There are three main
types of fire modifications that the chaparral flora has developed. There are
the obligate resprouters, obligate seeders, and facultative seeders. Obligate
resprouters are plants, such as the toyon, that depend on resprouting under the
earth after a fire for survival. Obligate seeders can be perennial shrubs, such
as the ceanothus species, and are terminated in the fire and rely on the fire
affected seeds to restart the next population. Faculative seeders, such as
manzanita, resprout and germinate
after a fire passes through. Making things more complicated, when fires are too
hot, they can destroy the buried root crowns of vegetation, making it more
difficult for plants to regenerate which can allow coastal scrub plants to take
over, altering the ecosystem.
According
to California Fire, “From 1997-2001, an average of 392 wildland fires were
caused by arson, burning 21,072 acres and causing over $3.2 billion in damage
annually”
To
sum up: The urbanization and conflicting views create a strain on fire
management in the chaparral region of southern California. The chaparral has
adapted a resiliency to flames and even requires them in order for flora to be
at their peak. Mosaic burning and suppression can be more harmful to the flora
than helpful and cause insufficiencies in diversity and density. By having a
system of fire management, planned at the right season and maintained to where
is can cleanse the biomass, the houses will be safe and the ecosystem can
thrive.
Amanda Cully, Communication 490, Humboldt State University, Fall Semester 2013
Recorded September 25, 2013 - Episode D
