INVESTIGADORES
BORGHI Carlos Eduardo
artículos
Título:
The effect of grazing on granivory patterns in the temperate Monte Desert, Argentina
Autor/es:
P. L. SASSI; TARABORELLI, P.; C. E. BORGHI; R. A. OJEDA
Revista:
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
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.