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

Grasslands of Patagonia 153
conditions, these debates are stimulating but somewhat theoretical. Simple and
flexible grazing strategies proved to be useful to optimize sheep production
and to prevent rangeland deterioration for most situations. Severe restrictions
limit the practical application of more complex grazing strategies.
Conflict between short- and long-term production
Many economic activities exhibit conflicts between short-term and long-term
profitability when environmental impact is considered. Maximum short-term
profits are attained by methods that may be harmful to natural resources , especially
if hidden environmental costs are, as usual, not included in economic
calculations. In this case, less profitable procedures in the short-term might be
chosen for environmental protection, or environmental costs should be included
in the economic analysis.
This seems not to be the case for Patagonian sheep farming systems . While
overgrazed farms are likely to produce not only more but also finer wool,
nutritional restrictions will decrease lambing rates and survival of adult sheep,
promoting decreases in overall meat sales. If overgrazing occurs in the most arid
biomes , reproduction and survival is depressed beyond the equilibrium point
of the flock and sheep population numbers decline (Golluscio et al., 1999).
A properly managed sheep farm sells 24 to 44 percent of the herd annually
(depending on the natural environment), whereas sales from overgrazed farms
range from zero to 15 percent (Borrelli et al., 1997). Consequently, sound management
pays off in the short term, even using conventional economic analysis.
This becomes more evident for mixed lamb and fine-crossbred-wool production
systems , but is also valid for fine-wool production systems.
The role of Decision Support Systems
The availability of computers broadens the possibilities for environmental
assessment and management by range technicians. The joint INTA-GTZ
project, mentioned above, introduced satellite imagery processing facilities and
skills in Patagonia . The use of Landsat TM images was adopted as a cost- and
time-efficient service to help make accurate inventories for rangeland surveys.
In some areas, carrying capacity could be estimated directly from Landsat
TM Images (Oliva et al., 1996). In others, image processing provided accurate
range site maps and useful information to guide field sampling. Geographical
Information System (GIS ) technology was used in 1994 to combine satellite
information with other data sources, such as soil maps, climatic data, property
boundaries and other significant variables. For vast and isolated regions such
as Patagonia, where farms cover big areas that are often hard to access with
vehicles and where there are few trained people to conduct range evaluations,
this technology multiplies human power and reduces operation costs.
Decision Support Systems (DSS ) are clearly a new dimension for range
management . Adaptive management information at the individual farm level