INVESTIGADORES
BEAMUD Sara guadalupe
congresos y reuniones científicas
Título:
Species coexistence and predictability mediated by functional equivalence as documented in an experimental approach
Autor/es:
KRUK, C., SEGURA, A. M., SARTHOU, F., NOGUEIRA, L., CABRERA, C. & G. BEAMUD
Lugar:
San Michele allAdige (Trento)
Reunión:
Congreso; 16th Workshop of the International Association of Phytoplankton Taxonomy and Ecology (IAP); 2011
Resumen:
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-->Phytoplankton
responses to environmental change are predictable when grouping
species using global indicators (i.e.,
chlorophyll a).
However, the specific composition is difficult if not impossible to
know in advance. Here, we use a morphology-based functional groups
(MBFG) approach and show that community structure and coexistence of
species depends on specific traits related to species ecological
aptitude. We carried out
experiments with natural communities and analyzed the succession
under different nutrient, temperature and predation levels. We
evaluated the temporal variation in total chlorophyll and phycocyanin
and the composition in terms of species and MBFG. Total biomass
(chlorophyll) and cyanobacteria (phycocyanin) developed most in high
nutrients and high temperature treatments. However, different
cyanobacteria species with similar
morphological traits can alternatively dominate or coexist in similar
environmental conditions. For example under high nutrients, high
temperature, and absence of large herbivores, large filamentous high
S/V potentially toxic cyanobacteria (MBFG III) dominate. However, we
found either Planktothrix agardhii,
Pseudanabaena
spp., Cylindrospermopsisraciborskii
or other taxa dominating or coexisting. This suggests that MBFG do
indeed contain functionally equivalent and therefore interchangeable
species. In line with the emergent neutrality theory, this means that
selection is acting on functional groups and the identity of a
particular species within such groups could be essentially random. The MBFG approach
integrates individual traits which can be related to ecological
processes at the community level at different temporal scales and
independently from geographical location. Within MBFG, species showed
similar responses to the environmental conditions and therefore might
be similarly affected by impact and restoring human activities. Thus
MBFG constitute a useful summarizing tool
to disentangle the effects of anthropogenic impacts on phytoplankton
responses.