INVESTIGADORES
GHERMANDI luciana
artículos
Título:
Seedling recruitment in a semi-arid Patagonian steppe of refuse dumps of leaf-cutting ants
Autor/es:
FARJI-BRENER A. & L. GHERMANDI
Revista:
JOURNAL OF VEGETATION SCIENCE
Referencias:
Año: 2004 vol. 15 p. 823 - 830
ISSN:
1100-9233
Resumen:
Abstract
Question: What is the influence of refuse dumps of leafcutting
ants on seedling recruitment under contrasting moisture
conditions in a semi-arid 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 elements, generating safe sites that
enhance the performance of neighbouring seedlings mainly
during the driest, stressful periods.