INVESTIGADORES
OJEDA Ricardo Alberto
artículos
Título:
The effect of grazing on granivory patterns in the temperate Monte desert, Argentina
Autor/es:
PAOLA SASSI, PAULA TARABORELLI, CARLOS BORGHI AND RICARDO A. OJEDA
Revista:
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
Editorial:
ELSEVIER
Referencias:
Año: 2006 vol. 29 p. 301 - 304
ISSN:
1146-609X
Resumen:
Structural variations result in a marked heterogeneity of processes in arid environments.
Disturbances have noticeable impacts on ecosystems, and a solid way of assessing their
effect is to analyze how ecological processes operate. In deserts, granivory has been considered
as a keystone process. The objective of our study was to determine the effect of
domestic grazing on seed removal rates by birds, ants and rodents as an indirect measure
of the process of granivory. This study was carried out in grazed and ungrazed habitats in
the central Monte desert ecoregion in Argentina, during February and July 2002. We analyzed
three major habitats: mesquite forest, creosotebush shrubland, and sand dunes under
two different treatments (grazed, ungrazed). We found significant effects of grazing
and non-grazing treatments on total seed removal rates, among granivorous taxa, as well
as interactions with season and habitats. Ants and birds were the taxa that differed most
under grazing pressure whereas seed removal by rodents showed no significant responses
towards grazing. In conclusion, grazing affects plant structure and the assemblage of
granivorous taxa, which in turn translates to the granivory process, adding another source
of variation to the seed removal patterns reported for the temperate Monte desert.