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

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Grasslands of the world
In 1989, INTA and GTZ launched a joint project to control and prevent
desertification in Patagonia , which was implemented during the 1990s. This
project increased societal awareness regarding desertification problems, and
3 percent of all sheep farmers in the region adopted the techniques recommended.
Since the early 1990s, interaction between farmers and range scientists
has increased and has resulted in the application of grazing plans at an individual
farm scale. This was possibly the birth of range management as a practical discipline
in Patagonia. After more than two decades of research activities and one
decade of practical experience, we have both recommendations and many new
questions.
Adaptive management – the Santa Cruz example
The designing of a grazing plan with little research background and a lot
of variation coming from weather, soils, vegetation and previous grazing
management is highly problematic. Stuart-Hill (1989), working in South
Africa , stated that it is almost impossible to define “proper” management in a
one-step plan. He proposed adaptive management as the only way to deal with
urgent decisions and limited knowledge rangelands. Our experience confirms
his hypothesis: proper management is a process rather than a single decision.
In Santa Cruz, for instance, many farms began to apply adaptive
management in the 1990s (Borrelli and Oliva, 1999) (Figure 4.6). Range
evaluation methods were used to support stocking rate adjustments and
other grazing allocation decisions. Annual monitoring of weather, vegetation
and animal production variables at the level of individual paddocks provided
feedback information that allowed the implementation of opportunistic
grazing plans and corrections for possible errors in the initial stocking
proposal. Farmer objectives and perceptions were very important in the
planning process. Opportunistic grazing plans in southern Santa Cruz
proved to be effective in terms of optimizing sheep production. Variable
stocking rates were used to take advantage of favourable years and also to
reduce the impact of periodic droughts , although it is not clear whether
variable stocking rates were more beneficial to vegetation than moderate
fixed stocking rates. Unfortunately, the vegetation attributes used as criteria
for stocking rate adjustments (short-grass biomass and key species height)
were inadequate for long-term monitoring.
The information collected on many sheep farms in southern Patagonia was
used by INTA Santa Cruz to create a regional database. This proved to be a
useful and simple tool to analyse the internal variation of carrying capacity
estimations within each natural environment and grazing site. Many inferences
made from small paddock grazing studies were confirmed at the commercial
scale. This information on animal and vegetation responses to grazing
management was important to calibrate stocking rate recommendations
across range types in Santa Cruz (Kofalt and Borrelli, unpublished data).