Descomposición de helófitos en un humedal semiárido hipertrófico

[摘要] This study represents the first attempt to outline the dynamics of litter decomposition ofCladium mariscus(cut-sedge) andPhragmites australis(common-reed) in Las Tablas de Daimiel National Park (Central Spain). From April 1998 to September 1999, two experiments were conducted to measure the overall decomposition in large-pore bags (7 months) and the chemical-microbiological decomposition in entire bags (14 months). Despite the hypertrophic condition of the wetland, that might have enhanced plant litter decaying rates, decomposition was a slow process in Las Tablas de Daimiel for both species, resulting in more than 50% of initial biomass a year and a half later. There were no significant correlations between environmental variables and decomposition rates. An initial phase of leaching with the highest rates (P�?1forC. mariscusand 0.0029 ± 0.002 day �?1forP. australisin the overall decomposition experiment, and respectively 0.0019 ± 0.001 day �?1and 0.0016 ± 0.001 day �?1due to chemical-microbiological decomposition, suggesting the negligible significance of invertebrates in the plant decomposition process. Furthermore, no significant difference was observed for nutrient release, except thatPhragmiteslost more phosphorus (PCladium . Plant litter decaying rates were roughly an order of magnitude lower than nutrient release rates in both species. Our results suggest that slow decomposition rates of helophitic plant biomass increases organic matter sedimentation and reduces water quality of Las Tablas de Daimiel National Park.

[学科分类] 植物学

[关键词] Cladium mariscus;decomposition;hypertrophic wetland;LasTablas de Daimiel National Park;leaching;nitrogen;phosphorus;Phragmites australis;Spain