Eclipse effects on field crops and marine zooplankton: the 29 March 2006 total solar eclipse

摘要

Some effects in the biosphere from the Total Solar Eclipse of 29 March 2006 wereinvestigated in field crops and marine zooplankton. Taking into account thedecisive role of light on plant life and productivity, measurements ofphotosynthesis and stomatal behaviour were conducted on seven importantfield-grown cereal and leguminous crops. A drop in photosynthetic rates, bymore than a factor of 5 in some cases, was observed, and the minimum valuesof photosynthetic rates ranged between 3.13 and 10.13 μmol CO₂ m−2 s−1. The drop in solar irradiance and the increase inmesophyll CO₂-concentration during the eclipse did not induce stomatalclosure thus not blocking CO₂ uptake by plants. Light effects on thephotochemical phase of photosynthesis may be responsible for the observeddepression in photosynthetic rates. Field studies addressing the migratoryresponses of marine zooplankton (micro-zooplankton (ciliates), andmeso-zooplankton) due to the rapid changes in underwater light intensitywere also performed. The light intensity attenuation was simulated with theuse of accurate underwater radiative transfer modeling techniques. Ciliates,responded to the rapid decrease in light intensity during the eclipseadopting night-time behaviour. From the meso-zooplankton assemblage, variousvertical migratory behaviours were adopted by different species.