INVESTIGADORES
ZAGARESE Horacio Ernesto
congresos y reuniones científicas
Título:
UVR Radiation as a Potential Driving Force for Zooplankton Community Structure in Patagonian Lakes
Autor/es:
CRISTINA MARINONE, MARÍA; MENU MARQUE, SILVINA; AÑÓN SUÁREZ, DIEGO; DIÉGUEZ, MARÍA DEL CARMEN; PÉREZ, ALEJANDRA PATRICIA; DE LOS RÍOS, PATRICIO; SOTO, DORIS; ZAGARESE, HORACIO
Lugar:
Beijin, China
Reunión:
Conferencia; Earth System Science Partnership Open Science Conference; 2006
Institución organizadora:
DIVERSITAS, IGBP, IHDP, and WCRP
Resumen:
This work explores the potential role of ultraviolet radiation to influence zooplankton community structure. First, we briefly review the effects of UVR exposure on zooplankton organisms, and the suite of counteracting strategies to mitigate its negative effects.  The purpose of this itroduction is to provide a general overview of UVR effects on freshwater zooplankton and to review the evidence specifically concerned with Argentine and Chilean environments.  Then, we present the results of an extensive survey of 53 temperate lakes in Argentina and Chile across a gradient of environments differing in the degree of UVR exposure.  The objective of this survey was to search for patterns of species richness and specific diversity.  Both species richness and specific diversity decreased with estimates of potential UVR exposure (i.e., mean water column irradiance and lake optical depth at 320 nm).  A threshold value of mean irradiance of about 10% of surface level seems to exist, around which both richness and diversity are limited to minimum values.  From the evidence collected in our field survey it is not possible to definitely conclude that UVR, and not some other co-varying parameter, is responsible for the decrease in specific diversity observed at the lowest end of lake optical depth, but regardless of the mechanism, “optically thin” lakes are likely to exhibit highly depauperate zooplankton communities.  As a cautionary note, we suggest that changes in the optical characteristics (i.e., changes in atmospheric conditions, precipitation patterns, or vertical displacement of the tree line) may result in sudden shifts in community structure of “optically thin” lakes.