| Sumario: | Crop production is traversing expansion and intensification processes all over the
planet and in consequence the large scale cattle production is being displaced to marginal
lands with lower stocking capacity. The objective of this work was to assess the seasonality
of vegetation in La Pampa province located in a semiarid region in Argentina and to
explore if the variations in seasonality are related to the stocking rate. The hypothesis is
the changes in stocking rate of rangelands and its grazing pressure alter the proportion
of different vegetation functional groups and so the vegetation seasonality. It is predicted
that overgrazing of seasonal grasses will alter the proportion of woody species having
consequences over spectral indices. It was analyzed satellite data, particularly the MODIS
Enhanced Vegetation Index (EVI) and related it to stocking rate records from SENASA.
This work evidences the relationship between the stocking rate and the spectral index
EVI, indicator of the primary productivity of vegetation, at departmental scale in the
natural areas of Monte and Espinal of La Pampa. Results indicate that in western region
(Monte) there was an increment in the stocking rate at department level and a decrease in
vegetation seasonality. It is posed that the higher grazing pressure led to the overgrazing
of the most palatable herbaceous species, increasing the shrub proportion in landscape.
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