Everything about Chaparral totally explained
Chaparral is a
shrubland or
heathland plant community found primarily in
California, USA, that's shaped by a
Mediterranean climate (mild, wet winters and hot dry summers) and wildfire. Similar plant communities are found in the five other Mediterranean climate regions around the world, including the
Mediterranean Basin (where it's known as
maquis), central
Chile (where it's called
matorral),
South African Cape Region (known there as
fynbos), and in Western and Southern
Australia.
The word
chaparral is a
loan word from
Spanish. The Spanish word comes from the word
chaparro, which means both small and dwarf evergreen oak, which itself comes from the
Basque word
txapar, with the same meaning.
A typical chaparral plant community consists of densely-growing evergreen
scrub oaks and other drought-resistant shrubs. It often grows so densely that it's all but impenetrable to large animals and humans. This, and its generally arid condition, makes it notoriously prone to wildfires. Although many chaparral plant species require some fire cue (heat, smoke, or charred wood) for germination, chaparral plants are not "adapted" to fire per se. Rather, these species are adapted to particular fire regimes involving season, frequency, intensity and severity of the burn.
Ecology of fire in chaparral
Chaparral is one of the most fire-prone plant communities in North America. As a consequence, since an increasing number of developments are pushing into the backcountry along what is known as the wildland-urban interface, management of the system has become increasingly important.
There are two assumptions relating to California chaparral fire regimes that appear to have caused considerable confusion and controversy within the fields of wildfire and land management: first, older stands of chaparral become “senescent” or “decadent” implying they need fire to remain healthy (Hanes 1971), and second, fire suppression policies have allowed chaparral to accumulate unnatural levels of fuel leading to larger fires (Minnich 1983).
The perspective that older chaparral is unhealthy or unproductive may have originated during the 1940s when studies were conducted measuring the amount of forage available to deer populations in chaparral stands. However, according to recent studies, California chaparral is extraordinarily resilient to very long periods without fire (Keeley, J.E., A.H. Pfaff, and H.D. Safford 2005) and continues to maintain productive growth throughout pre-fire conditions (Hubbard 1986, Larigauderie et al. 1990). Seeds of many chaparral plants actually require 30 years or more worth of accumulated leaf litter before that'll successfully germinate (for example scrub oak:
Quercus berberidifolia, toyon:
Heteromeles arbutifolia, holly-leafed cherry:
Prunus ilicifolia). When intervals between fires drop below 10 to 15 years, many chaparral species are eliminated and the system is typically replaced by non-native, weedy grassland (Haidinger and Keeley 1993, Keeley 1995, Zedler 1995).
The idea that older chaparral is responsible for causing large fires was originally proposed in the 1980’s by comparing wildfires in Baja California and southern California. It was suggested that fire suppression activities in southern California allowed more fuel to accumulate which in turn led to larger fires (in Baja, fires often burn without active suppression efforts). This is similar to the argument that fire suppression in western United States has allowed
Ponderosa Pine forests to become “overstocked.” In the past, surface-fires burned through these forests at intervals of anywhere between 4 and 36 years, clearing out the understory and creating a more ecologically balanced system. However, chaparral has a crown-fire regime, meaning fires consume the entire system whenever they burn. Detailed analysis of historical fire data has shown that fire suppression activities have failed to exclude fire from southern California chaparral as they've in Ponderosa Pine forests (Keeley et al. 1999). In addition, the number of fires is increasing in step with population growth. Overall, chaparral stand age doesn't have a significant correlation to its tendency to burn (Moritz et al. 2004). Low humidity, low fuel moisture, and high winds appear to be the primary factors in determining when a chaparral stand burns.
Species
In Central and
Southern California chaparral forms a dominant habitat. Members of the chaparral biota native to California, all of which tend to regrow quickly after fires, include:
Further Information
Get more info on 'Chaparral'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://chaparral.totallyexplained.com">Chaparral Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
