INVESTIGADORES
BORTOLUS alejandro
artículos
Título:
Underestimation of Spartina production in western Atlantic marshes: marsh invertebrates eat more than just detritus.
Autor/es:
B SILLIMAN,; ALEJANDRO BORTOLUS
Revista:
OIKOS
Editorial:
Blackwell Publishing
Referencias:
Año: 2003 vol. 101 p. 549 - 554
ISSN:
0030-1299
Resumen:
Quantifying primary productivity and understanding
the factors that control plant growth are primary goals
of ecosystem ecology. Although some methods have
been very successful in providing accurate measurements
of plant growth and elucidating the importance
of both physical and biological factors in regulating
primary production (e.g. terrestrial systems: Smith
1996; marine communities: Bertness et al. 2001), many
techniques are still hampered by methodological biases
that greatly affect productivity estimates and overall
experimental results. For example, a recent review of
tropical seagrass systems suggests that past experiments
investigating seagrass productivity may have been compromised
because they did not control for the confounding
effects of grazing (i.e. monitoring and/or
excluding fish and invertebrate grazers Valentine and
Heck 1999). The authors argue that the probable consequences
of not accounting for herbivore effects are: (1)
inaccurate estimates of both net and gross primary
production and (2) an intellectual bias concerning the
relative roles of bottom-up (i.e. nutrients and nutrient
regulating factors) and top-down (e.g. herbivory) forces
in controlling seagrass growth. In this paper, we argue
that these conclusions also apply broadly to salt
marshes along the East Coast of both North and South
America. Specifically, we suggest that past studies of
plant productivity in Western Atlantic marshes, by not
accounting for the confounding effects of grazing (i.e.
excluding herbivorous crabs and snails), are likely to
have significantly underestimated plant growth and
overestimated the relative importance of bottom-up
factors in regulating marsh primary production.