138 CHAPTER 6 Ecosystems and Evolutionso steep that firefighters often cannot
use mechanized equipment but must
transport equipment to fires with
helicopters. Afraid that prescribed
burns will get out of control, local
governments are increasingly trying an
effective, low-tech method to reduce
the fuel load: During the 6-month fire
season, goats are clearing hills around
Oakland, Berkeley, Monterey, and
Malibu.
A herd of 350 goats can clear an
entire acre of heavy brush in about
a day, but their use entails advance
organization and support. Before
goats can remove hazardous dry fuels
from surrounding hillsides, botanists
must fence off small trees and rare or
endangered plants, to keep the goats
from eating those plants. Goats are
confined with installed electric fencing,
and the goatherds typically use dogs
to help herd the goats. Responsible
management includes grazing the goats
for the optimal amount of time—long
enough to reduce the threat of fire but
not so long as to cause unnecessary
erosion in the area.
Goats are an excellent tool for fire
management because they preferentially browse woody shrubs
and thick undergrowth—exactly the fuel that causes disastrous
fires. Fires that have occurred in areas after goats have browsed
there are much easier to contain.EnviroDiscovery
Using Goats to Fight Fires
California has about 6000 wildfires each year, and they are
becoming increasingly expensive and dangerous to manage
because many people are building homes and living in the
fire-vulnerable chaparral. Yet the topography of chaparral isDavid McNew/Newsmakers/Getty
Goats prefer woody and weedy species, such as those common to chaparral.Desert
Desert consists of dry areas found
in both temperate (cold deserts)
and subtropical or tropical re-
gions (warm deserts). The low
water vapor content of the des-
ert atmosphere results in daily
temperature extremes of heat and cold, so that a ma-
jor change in temperature occurs in each 24-hour pe-
riod. Deserts vary greatly depending on the amount ofThe fires that occur in California chaparral are quite
costly to humans when they consume expensive homes
built on the hilly chaparral landscape. Unfortunately, ef-
forts to prevent the naturally occurring fires sometimes
backfire. Denser, thicker vegetation tends to accumulate
over several years; then, when a fire does occur, it is much
more severe. Removing the chaparral vegetation, whose
roots hold the soil in place, causes other problems; wit-
ness the mudslides that sometimes occur during winter
rains in these areas.desert A biome
in which the lack
of precipitation
limits plant growth;
deserts are found in
both temperate and
tropical regions.