IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Interaction of position, litter type, and water pulses on decomposition of grasses from the semiarid Patagonian steppe
Autor/es:
AUSTIN, A.T.; ARAUJO, P.I.; LEVA, P.E.
Revista:
ECOLOGY
Editorial:
Ecologia Society of America
Referencias:
Año: 2009 vol. 90 p. 2642 - 2647
ISSN:
0012-9658
Resumen:
Litter lignin and nutrient content, annual rainfall and biotic activity are not good predictors of litter decomposition in arid and semiarid ecosystems, suggesting that other factors may be important controlling carbon turnover. We explored the relative importance of litter position (above- vs. belowground), litter type (leaf vs. root), and pulsed water events (large vs. small) on mass loss with grass species of the semiarid Patagonian steppe. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. The results of this mesocosm experiment support the idea that controls other than water availability may dominate aboveground mass loss, while a combination of recalcitrant litter and water penetration in the soil profile are critical factors determining belowground decomposition, which is ultimately mediated by biotic degradation.