Decomposition of cattle manure and colonization by macroinvertebrates in sediment of a wetland of the Middle Paraná River

MESA M.L., MALDINI C., MAYORA G., SAIGO M., MARCHESE M., GIRI F

JOURNAL OF SOILS AND SEDIMENTS (PRINT)

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2016

1439-0108

Purpose The study was carried out in a wetland of the MiddleParaná River system, Argentina, in order to evaluate the processesassociated with the decomposition of manure, whichincludes changes in chemical composition, nutrient release ofmanure, and colonization of invertebrates. We also comparedthe invertebrate assemblage that colonized manure with thatpresent in the benthos of the wetland.Materials and methods Nylon bags were filled with fresh cattlemanure and anchored to the littoral zone of the wetland. Sixbags were collected after 1, 2, 6, 14, 21, 28, 33, 55, and79 days: three for invertebrate determination and the otherthree bags for determination of dry mass and chemical analyses.The nutrient content, cellulose, lignin, and total phenoliccompounds of manure were determined. In addition, theleachate of manure was collected for nutrient analyses.Samples of the wetland benthic sediment were collected forbenthic invertebrate determination and particle size analyses.Spearman rank correlation was used to evaluate the relationshipbetween chemical compounds of manure and breakdownrate. Principal component analysis was used to explore invertebrateassemblage composition of manure and sediment duringthe experiment.Results and discussion Limnodrilus, Dero, and Chironomuswere dominant in the manure. Gatherer-collector was thedominant group in the manure, comprising almost 95 % ofthe total density of invertebrates. Breakdown rate was significantlyrelated with nutrients, cellulose and total phenolics ofmanure. An ordination plot showed changes in invertebrateassemblages of manure and sediment samples over time.Conclusions This study provides new insight on the importanceof manure as a substrate for macroinvertebrate colonization.Cattle manure needs to be considered as a potentialsource of nutrients for aquatic systems and a substrate forinvertebrate assemblages.