Fire - Agroecology: The Ecology of Sustainable Food Systems - page 143

grazing systems is not really that common. When fire is
used in grazing systems, it is employed in the form of a
controlled fire known as a prescribed burn. A prescribed
burn in a grazing agroecosystem can play many roles.
It can:

• prepare a seedbed for natural or artificial seed-

ing of desired plant species

• stimulate some plants to produce seed

• encourage growth of native legumes for forage

and soil improvement

• promote more rapid nutrient cycling and

uptake

• burn off unpalatable growth from previous sea-

sons that is not eaten by most animals and that
would otherwise compete with more desirable
species

All of these potential effects of fire can play important
roles in determining the most appropriate regime of man-
agement using fire.
The relative importance of each of the impacts of
burning varies with the type and intensity of grazing sys-
tem, time since the last fire, season of the year, and the
stage of development of the edible plants. In open grass-
land, for example, there is little tendency for woody spe-
cies to invade; therefore fire is employed to remove the
accumulation of inedible growth. In savanna regions, or
areas where natural succession would favor shrub or tree
vegetation, burning is of much greater importance for
suppressing some plants while establishing or maintaining
the pasture components (Figure 10.9).

• stimulate growth (in the form of fire-response

sprouting of perennial plants) during times of
the year when very little green growth would
normally be available

• destroy parasites such as ticks and fleas that can

carry stock disease

• control the spread of undesirable plants in pas-

ture or range

• remove the fire hazard of accumulated old

browse or grass

• establish fire breaks as a system of protection

from wildfire

FIGURE 10.9 Chaparral species invading grassland, Santa Barbara County, CA. Fire is needed to periodically repress the
shrubs and promote grass for grazing.