INVESTIGADORES
AIZEN Marcelo Adrian
artículos
Título:
Endozoochory decreases environmental filtering imposed to seedlings
Autor/es:
CAVALLERO, L., M.A. AIZEN Y E. RAFFAELE
Revista:
JOURNAL OF VEGETATION SCIENCE
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012 vol. 23 p. 677 - 689
ISSN:
1100-9233
Resumen:
Questions: Recruitmentmicrosites are imposed on plants, first by seed dispersal
and then by the environment. Different seed dispersal vectors could decrease or
increase the environmental filtering imposed on seedlings, depending on their
specificity to deliver seeds to suitable microsites for germination and establishment.
We addressed the hypothesis that endozoochory reduces the environmental
filtering imposed to seedlings to a larger extent than does anemochory.
We predicted that seedlings from animal-dispersed species should show a higher
degree of environmental coupling.
Location: Northern Patagonian Andean region of Argentina, 40?42° S.
Methods: We characterized the relationship of seedlings, saplings and reproductive
individuals to total radiation, air temperature and relative humidity for
16 woody species growing in 25 plant communities of different post-fire ages in
temperate forests of southern South America.
Results: Seedlings and saplings of endozoochorous species occurred undermore
similar environmental conditions than seedlings and saplings of anemochorous
species. Basically, the mean difference in plant?environment correlation coefficients
between saplings and seedlings was 0.2 for all anemochorous species for all environmental variables. Comparisons
between dispersal modes were also statistically significant before and after
controlling for phylogenetic relationships among species. Even though saplings
and seedlings of endozochorous species tended to occur under similar environmental
conditions, we did not find evidence that saplings and seedlings co-occur
in the same physical microsites. Finally, we did not find evidence either that
seedlings of endozoochorous species tended to occur differentially underneath
reproductive individuals of the same species (i.e. more seeds falling by gravity
beneathmaternal plants).
Conclusions: The tighter coupling between seedlings of endozoochorous species
and environmental factors persisting to the sapling stage suggests that relying
on animals for seed dispersal reduces mortality costs during the early stages
of recruitment by reducing the environmental filtering imposed on seedlings.