Alternatives to Slash-and-Burn 357(Cairns and Garrity, 1999). Improved fallows using leguminous cover crops kept
in the field for less than 2 years occur in Peru and include kudzu (Pueraria phase-
oloides [Roxb.] Benth) (Sanchez and Benites, 1987), Mucuna spp., and Centrosema
macrocarpum Benth. (Palm et al, 2002a).
Continuous food crop production
Continuous cropping is found in valley bottoms as irrigated paddy rice (Oryza
sativa L.) in Indonesia, Peru and Thailand, but because it is so well established and
is rarely associated with slash-and-burn and deforestation it was not included in the
analysis by ASB (except in Thailand). In Cameroon and Thailand, intensive horti-
culture with high rates of use of mineral fertilizers and pesticides forms an important
option near the large urban centres of Yaoundé and Chiang Mai. Cassava is grown
continuously in the Lampung area of the Indonesian benchmark site, particularly on
transmigration settlement sites, and often eventually degrades through invasion by
Imperata cylindrica into landscape patches or large grasslands.
Pastures and grassland systems
Pastures for beef production dominate the deforested landscape in the Brazilian
and Peruvian benchmark sites. These include traditional, extensive pasture systems
that degrade within a decade or so, as well as more intensive grazing systems with
improved grass species (Brachiaria humidicola [Rendle] Schweick; B. brizantha
[Hochst.] Stapf ) often mixed with pasture legumes such as Pueraria phaseoloides,
Desmodium ovalifolium Wall, Arachis pintoi Krap. & Greg., and others (Serrão et al,
1979; Serrão and Toledo, 1990). The pasture species are tolerant to aluminum
toxicity and are normally planted into a preceding crop of upland rice or maize
(Zea mays L.). In parts of Brazil, these pastures are rejuvenated by burning, plough-
ing and fertilizing a maize crop to which pastures are replanted.
Extensive areas of Imperata cylindrica grasslands occur throughout South-East
Asia and parts of West Africa. This species is known as alang-alang in Indonesia
and cogon in the Philippines. These grasslands are dominant in the Lampung area
of the Indonesian benchmark site (Garrity, 1997). This coarse, unpalatable grass
invades areas where the fallow cycle has been shortened and is basically a degraded
system. It is difficult to eradicate and is maintained by frequent fires. Fortunately
Imperata cylindrica grasslands do not occur in Latin America, where less invasive
Imperata species exist and pose no major problems.
These meta–land-use categories were used to set up land-use intensity transects
or chronosequences at several locations in each benchmark site where environmen-
tal, agronomic and socioeconomic factors were evaluated by standard protocols.
Whenever and wherever possible the different measurements were all taken from
the same plot, farm or location in the landscape. Natural forest was considered the
point of departure for all land uses, and grasslands, short-fallow cultivation systems
and pastures were included as the other endpoint, representing degraded conditions.
The specific environmental, agronomic and socioeconomic measurements are
described in the sections that follow.