INVESTIGADORES
FARJI-BRENER Alejandro Gustavo
artículos
Título:
Seedling recruitment in the semi-arid Patagonian steppe: facilitative effects of refuse dumps of leaf-cutting ants.
Autor/es:
ALEJANDRO GUSTAVO FARJI BRENER; GHERMANDI, L
Revista:
JOURNAL OF VEGETATION SCIENCE
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2004 vol. 15 p. 823 - 830
ISSN:
1100-9233
Resumen:
Question: What is the influence of refuse dumps of leaf-cutting ants on seedling recruitment under contrasting moisture conditions in a semiarid steppe? Location: Northwestern Patagonia, Argentina. Methods: In a greenhouse experiment, we monitored seedling recruitment in soil samples from refuse dumps of nests of the leaf-cutting ant Acromyrmex lobicornis and non-nest sites, under contrasting moisture conditions simulating wet and dry growing seasons.  Results: The mean number of seedling species and individuals were higher in wet than in dry plots, and higher in refuse dump plots than in non-nest soil plots. The positive effect of refuse dumps on seedling recruitment was greater under low moisture conditions. Both the accumulation of discarded seeds by leaf-cutting ants and the passive trapping of blowing-seeds seems not explain the increased number of seeds in refuse dumps. Conversely, refuse dumps have higher water retention capacity and nutrient content than adjacent non-nest soils, allowing the recruitment of a greater number of species and individual seedlings. Conclusions: Nests of A. lobicornis may play an important role in plant recruitment in the study area, allowing a greater number of seedlings and species to be present, hence resulting in a more diverse community. Moreover, leaf-cutting ant nests may function as nurse plants, generating safe-sites that enhance the performance of neighboring seedlings mainly during the driest, stressful periods.