1 research outputs found
Responses of microbially driven leaf litter decomposition to stream nutrients depend on litter quality
Este artĂculo contiene 14 páginas, 4 figuras, 1 tabla.The present study aims to understand how
microbial decomposition of leaf litter from two
riparian tree species differing in their quality varies
among streams covering a gradient of nutrient
concentrations. We incubated leaf litter from alder
(Alnus glutinosa) and sycamore (Platanus9hispanica)
in 3 streams with low human pressure and 2 streams
influenced by wastewater treatment plant effluents.
We quantified leaf litter decomposition rates (k) and
examined the temporal changes in the leaf litter
concentrations of carbon (C) and nitrogen
(N) throughout the incubation period. We measured
the extracellular enzyme activities involved in degradation
of C (i.e., cellobiohydrolase) and organic
phosphorus (i.e., phosphatase). Results showed that
alder k decreased with increasing nutrient concentrations,
while sycamore decomposed similarly among
streams. For both species, leaf litter N concentrations
were positively related to in-stream dissolved N
concentrations. However, we found different temporal
patterns of leaf litter N concentrations between
species. Finally, we found relevant differences in the
enzymatic activities associated to each leaf litter
species across the nutrient gradient. These results
suggest that the intrinsic characteristics of the leaf
litter resources may play a relevant role on the
microbially driven leaf litter decomposition and
mediate its response to dissolved nutrient concentrations
across streams.The financial support was provided by the Spanish
Ministry of Science and Innovation through the MEDFORESTREAM
(ref: CGL2011-30590-C02-02) project.
E. Bastias was granted by a FPI PhD fellowship from the
Spanish Ministry of Science and Innovation through the MEDFORESTREAM
project. M. Ribot was supported by a
technical training contract also associated to MEDFORESTREAM
project. Funding was provided by Consejo
Superior de Investigaciones Cientı´ficas (Grant No. BES-2012-
053358).Peer reviewe