Grasslands of the World.pdf - Disasters and Conflicts - UNEP

Grasslands of Patagonia 139
settlements and on the best pastures. (2) Small and medium commercial farms,
in the drier areas, with flocks of 1 000 to 6 000; these have serious financial
problems due to present wool prices. (3) Subsistence farms, with less than 1 000
sheep , mainly in northwestern Patagonia , which belong mostly to aboriginal
families and graze on unfenced public lands.
More than half of sheep farmers in Patagonia are very poor and together
own less than 10 percent of total sheep (Casas, 1999; Table 4.2). Most of the
other half is limited by farm size, so at present net farm income does not
satisfy their economic expectations. A few companies run sheep farms that
can be considered economically viable. Company farms own approximately
40 percent of the sheep. There is a marked increasing north-south farm size
gradient, beginning in the northwest (Neuquén), where subsistence farms
are commonest, to Tierra del Fuego, where large company-owned farms are
more frequent than in any other province (Table 4.2). The combination of
biozone and farm size (which is related to the kind of farm operation) gives a
wide range of pastoral systems , differing in terms of objectives, productivity
and sustainability .
GRAZING MANAGEMENT
Farmers make grazing management decisions based on subjective criteria and
previous experience (Golluscio et al., 1999). Paddocks are grazed continuously
(year-round), except on high altitude ranges grazed in summer (Borrelli
and Oliva, 1999). Vast areas, with few paddocks, restrict the possibilities
of controlling grazing, especially when paddocks include grazing sites with
contrasting forage availability (e.g. meadows and arid steppes) (Golluscio et
al., 1999).
Determining stocking rates is the most important decision in developing
a grazing plan (Heady and Child, 1994). The National Institute for
Agricultural Technology (INTA), Argentina , with the aid of GTZ (Deutsche
Gesellschaft für Technische Zusammenarbeit), developed range evaluation
methods, based on satellite imagery and field measurements, which provide
objective information for the formulation of sound grazing plans. Improved
management is based on adaptive management that consists of a planningexecution-monitoring
-evaluation cycle (Borrelli and Oliva, 1999).
Traditional management caused continuous overgrazing in most of the
region, which in turn led to general degradation (Oliva, Rial and Borrelli,
1995; Consorcio DHV, 1999). Del Valle (1998) estimated that 65 percent of
Patagonia was seriously degraded, 17 percent was moderately degraded and
only 9 percent was lightly affected. In no area was grazing impact negligible.
The DHV report estimated that 75 percent of Patagonian meadows were
severely degraded (Consorcio DHV, 1999). A few small-scale farmers have
adopted the recommended practices, with good results in terms of both animal
production and rangeland conservation (Borrelli and Oliva, 1999).