Shoot litter breakdown and zinc dynamics of an aquatic plant, Schoenoplectus californicus

ARREGHINI, SILVANA; DE CABO, LAURA; SERAFINI, ROBERTO JOSÉ MARÍA; FABRIZIO DE IORIO, ALICIA

INTERNATIONAL JOURNAL OF PHYTOREMEDIATION

TAYLOR & FRANCIS INC

Año: 2018 vol. 20 p. 780 - 788

1522-6514

Decomposition of plant debris is an important process in determining the structure and function ofaquatic ecosystems. The aims were to find a mathematic model fitting the decomposition process ofSchoenoplectus californicus shoots containing different Zn concentrations; compare the decompositionrates; and assess metal accumulation/mobilization during decomposition. A litterbag technique wasapplied with shoots containing three levels of Zn: collected from an unpolluted river (RIV) and fromexperimental populations at low (LoZn) and high (HiZn) Zn supply. The double exponential modelexplained S. californicus shoot decomposition, at first, higher initial proportion of refractory fraction in RIVdetritus determined a lower decay rate and until 68 days, RIV and LoZn detritus behaved like a source ofmetal, releasing soluble/weakly bound zinc into the water; after 68 days, they became like a sink. However,HiZn detritus showed rapid release into the water during the first 8 days, changing to the sink conditionup to 68 days, and then returning to the source condition up to 369 days. The knowledge of the role ofdetritus (sink/source) will allow defining a correct management of the vegetation used for zinc removaland providing a valuable tool for environmental remediation and rehabilitation planning.