The effect of sunlight on leaf litter quality reduces growth of the shredder Klapopteryx kuscheli.

ALBARIÑO, RICARDO; DÍAZ VILLANUEVA, VERÓNICA; CANHOTO, CRISTINA

FRESHWATER BIOLOGY (PRINT)

Blackwell Publishing Ltd

Lugar: Oxford; Año: 2008 p. 1881 - 1889

0046-5070

SUMMARY1. The direct effect of sunlight on the conditioning, breakdown and incorporation of leaf litterin stream food webs has not yet been considered. The aim here was to evaluate the effects oflight intensity on the colonization of leaf litter by microorganisms and its resulting quality asfood for the stonefly shredder Klapopteryx kuscheli.2. Leaf litter was conditioned for 2 months in an open reach of a second-order stream in litterbags either exposed to or shaded from direct sunlight. Subsequently, we performed laboratoryexperiments to test larval consumption, growth, growth efficiency and feeding preference fedon both leaf litter treatments.3. Leaf litter in the unshaded treatment had three times more chlorophyll-a (Chl-a) than thatin the shaded treatment, 50% lower fungal biomass and similar bacterial abundance. Althoughlarvae did not prefer either food and fed at the same rate on both leaf litter treatments, theygrew twice as fast on the shade-conditioned leaves and attained a two-fold higher growthefficiency.4. Sunlight can have significant effects on detritus-based food webs. Riparian modificationinduced by human activities in forested catchments increases the potential for sunlight toinfluence detritus dynamics.