INVESTIGADORES
ESCAPA carlos mauricio
artículos
Título:
Crab bioturbation and herbivory reduce pre- and post-germination success of Sarcocornia perennis in bare patches of SW Atlantic salt marshes
Autor/es:
JUAN ALBERTI; MAURICIO ESCAPA; PEDRO DALEO; AGUSTINA MENDEZ CASARIEGO; OSCAR IRIBARNE
Revista:
MARINE ECOLOGY PROGRESS SERIES
Editorial:
INTER-RESEARCH
Referencias:
Año: 2010 vol. 400 p. 55 - 61
ISSN:
0171-8630
Resumen:
Colonization of bare
patches is a key process during community development given that
pioneers usually have positive and negative effects on the forthcoming
species. A variety of biotic and abiotic factors influence the process
of colonization of bare patches. In salt marshes, however, the emphasis
has been on abiotic factors and plantplant interactions, while
comparatively little attention has been paid to the role of
plantanimal interactions in the successful colonization by pioneer
plants. Thus, the goal of the present study was to evaluate whether
bioturbation and herbivory by the burrowing crab Neohelice (Chasmagnathus) granulata affected the number of seedlings of the pioneer plant Sarcocornia perennis in
SW Atlantic salt marshes. To evaluate this, we conducted an experiment
using exclosures deployed at different times (post-dispersal and
post-germination). The results showed that post-germination exclosures
had 62% fewer seedlings than post-dispersal exclosures but 8 times more
than plots always accessible to crabs. We also used glass beads to
experimentally evaluate the potential effect of crab bioturbation on
seed availability, and we used 1 yr old transplants to evaluate whether
herbivory could explain post-germination mortality. Crab bioturbation
reduced the number of glass beads on the surface by 56%, and
transplants were highly consumed when crabs were present. These results
suggest that seed burial by bioturbation exerts a pre-germination
control while herbivory exerts a post-germination control. The results
also highlight the importance of considering biotic factors when
analyzing the success of marsh plants colonizing bare surfaces.