DS-SLM en Argentina: un “pequeño” proyecto de gran impacto

Pilot site semi-arid Chaco

1. Radio communication on SLM and training of local actors on specific SLM technologies to strengthen Peasant Production.
   
2. Incorporation of the SLM technologies in the formal education system at secondary school level.

Pilot site Cuenca Arroyo Estacas

1. Aldea Santa María and Tierra Gaucha demonstration sites with conservation terraces, forest and livestock management, for the implementation of the Soil Conservation Act (8318).
   
2. Capacity building on the construction of terraces for professionals from different institutions and organizations who presented conservation projects for implementation.

For the elaboration of the LUS Map at national level, the LUS map of the drylands developed within the LADA project framework (2011) was used as a basis. In addition, the Soil Cover map (INTA 2007) was available as basic information. This map was reinterpreted and complemented with other information layers (livestock statistics by department, forest plantations map, protected areas and glaciers map) to obtain the Argentina LUS map.

A hierarchical system, based on WOCAT, was used to define the LUS: the map with level 1 has 9 LUS, the level 2 map defines 19 LUS and level 3 has 25 LUS classes. The 1st version (not validated yet) of the LUS map of Argentina includes until level 3. For the validation, an application was developed to consult local experts from each region of the country. The application allows each local expert to have access to the map, view the polygons and enter comments about the defined LUS.

With the consultation of local experts, 60.6% (1421 polygons) of the country surface was validated. Based on the experts opinions, 335 LUS polygons (6.5% of the country's surface) were reassigned. In this way, the final map of LUS, level 3, was obtained.

For the land degradation assessment at the national level through the local experts methodology (WOCAT-LADA QM questionnaire), the following difficulties were considered:

• Argentina is a very large country (8th biggest country worldwide). For that reason, the LUS map has a lot of polygons (9042).
• The LADA experience - where the QM methodology was applied for dryland areas of the country, with a lower categorization and for only a few number of polygons for each region (due to the cost associated with carrying out the validation workshops) - was very relevant, but the replication of this methodology was too expensive due to the extension of the country and its diversity of LUS.

Therefore, the QM was conducted online by experts in the pilot areas of the National Observatory of Land Degradation and Desertification and, as a complement to this, we have worked on the generation of degradation indicators using remote sensors.

Degradation indicators were generated based on the analysis of MODIS satellite images time series (2000-2014):

• Linear trend of the NDVI index. Significant and negative trends would indicate a loss of the primary productivity of ecosystems.
• BFAST analysis of the NDVI time series. This allows to identify the occurrence of abrupt changes, which can be associated with fires, land use changes, climatic events, etc.
• Currently, we are working on the analysis of the precipitation-NDVI ratio at pixel level and the analysis of the residual trend of this relationship. This will allow to discriminate the areas that show NDVI tendencies due to the climatic variations of those where the causes are anthropic.

The map shows the trend of the NDVI index in the period 2000-2014. 57% of the surface showed negative trend, 5% positive tendency, and 38% did not show significant changes. In addition, the areas where the negative tendencies were more pronounced are differentiated (red color on the map).

From the analysis of the BFAST there are 8 types of change of the NDVI index (with or without the presence of sudden changes). This supposes an advance with regard to the analysis of the linear tendency since the detection of abrupt changes (type of change and moment of occurrence) provides information about the causes of said changes. Abrupt changes can be associated with the occurrence of clearings, fires, natural events, etc. Therefore this information helps to interpret the NDVI trend maps. In the north of the country the occurrence of strong negative tendencies of the NDVI (red color) is associated with the occurrence of changes in land use (replacement of native forest by pastures or crops). Another example from the south (Patagonia) shows the area with the most negative NDVI tendencies, which coincides with the area affected by the deposition of volcanic ash from the Caulle-Puyehue volcano (eruption June 2011).

Another indicator of land degradation that was generated at national level is the estimation of water erosion applying the universal soil loss equation (USLE). Water erosion is the most widespread process of land degradation in Argentina. The factors that control the process of water erosion were estimated and mapped and allow applying the USLE equation: rain erosivity, soil erodability, grade and length of the slope (topographic factor) and vegetation cover. In this way, potential and current water erosion at the national level was mapped.

The map shows the current water erosion rates in tons per hectare / per year in the country. The map shows on the right the areas where the current erosion exceeds the tolerance limits (between 0.5 and 10 ton / ha / year according to the region of the country). From this map appears that 26% of the national surface presents erosion rates that exceed the tolerance limits.

A web application was developed to consult local experts about LUS degradation (WOCAT-LADA QM). This survey is currently being developed were a network of experts is working in Pilot areas that make up the National Observatory of Land Degradation and Desertification. The information from the application of the QM in Pilot sites will be crossed with the indicators generated by remote sensors. This will help in the indicators’ interpretation and validation.

On February 2016, the National Observatory of Land Degradation and Desertification (ONDTyD), called for potential sites. There were 4 work proposal evaluated by the Steering committee. The Steering committee, based on the steering committee of the ONDTyD, comprises the following institutions: the Ministry of Environment, the University and research centers. The selection criteria were:

• representativeness of the site;
• presence of critical processes of land degradation
• evidence of change of use
• work team
• linkage with local actors; and
• institutional endorsement.
  

On March 2016, 2 sites were selected:

Site 1: Semi-arid Chaco salteño (grazing land, dryland)

Site 2: Cuenca Arroyo Estacas, Entre Ríos (cropland and grazing land in humid area)

In Argentina, the project utilizes the existing structures, such as the National Observatory of Land Degradation and Desertification (ONDTyD), which continues the studies made by the LADA project and, incorporates humid areas. The project strengthens the activities carried out by the ONDTyD and the Secretary of Environment and Sustainable Development with the objective to solve the demands of the country.

ONDTyD makes biophysical and socioeconomical assessments and the monitoring of the 15 sites in different ecosystems. The same methodology and the same group of indicators are used in each one of them. On the website of the ONDTyD you can find more details of methodologies and indicators. 

Six good practices guidelines were produced and can be downloaded under 'Publicaciones'.

The SLM territorial planning has not been implemented yet, however, the results (maps, management practices) from the other modules, will be used as inputs when the module 5 is implemented within the framework of another GEF project (Territorial Environmental Ordering  TEO).

Pilot site semi-arid Chaco

It is a site located in drylands with scarce rainfalls in summer and, characterized by a xeric forest, that is, a dry and thorny forest. Low rainfalls, high temperatures and soil characteristics are severe environmental constraints that limit forage production in the region.

In the area, there are businessmen who are cattlemen dedicated to intensive livestock breeding, based on replacing the forest with tropical pastures. Or, by selective clearing of certain species and Desbarejado (elimination of the stratum under the trees – herbaceous and shrub).

The traditional cattle management involves cattle under free range conditions and without fences. Therefore, due to the climatic conditions of the area and the presence of cattle, the herbaceous stratum is disappearing and producing a decrease in productivity.  With the technology called "Deschampado", the dead branches of the forest are removed and pastures are created for cattle. In this way, the clearing and loss of biodiversity is avoided, fragmentation of the passage is avoided, water erosion reduced and others.

Pilot site Cuenca Arroyo Estaca

The site is located in a humid area with sloping soil. It is characterized by a Prosopis forest which is threatened by clearing due to agriculture. These are lands suitable for cattle and the main crops are soy, wheat, corn and sorghum.

Technology 1: The collector channel has a slope and grass which allows the drainage and infiltration of water. The “paño” (distance between level curves and the collector channel) decreases the slope of the soil. The crops are shown on the “paño”, following the level curves.

Technology 2: Smooth and vegetated hill connects rivers acting as a biological corridor. This practice is more expensive and complicated for its management (machineries) as it includes leaving forest corridors in the middle of terraces with crops.

The project allowed strengthening the existing situation. The management plan is self-managed and, the project links to the mitigation and prevention of desertification. On the other hand, there is the scientific portal with the methodologies and indicators of ONDTyD and, with the biophysical and socio-economical assessments from the 15 sites.

More information is available here:

www.desertificacion.gob.ar

www.infodesert.gob.ar