INVESTIGADORES
GOMEZ Nora
artículos
Título:
Effects of nutrient enrichment on epipelic diatom assemblages in a nutrient-rich lowland stream, Pampa Region, Argentina.
Autor/es:
LICURSI M.; GÓMEZ N.; SABATER, S.
Revista:
HYDROBIOLOGIA
Editorial:
SPRINGER
Referencias:
Año: 2016 vol. 766 p. 135 - 150
ISSN:
0018-8158
Resumen:
We analyzed the diatom assemblagesinhabiting the epipelic biofilm of a Pampean stream,characterized by their high basal nutrient levels, whenexposed to a continuous surplus of inorganic nutrients.An in situ experience was conducted, increasingconcentrations of N and P in water 3-fold from thebasal concentration. Nutrient enrichment wasachieved by the use of fertilizer bags distributed alongthe reach. The period of exposure was of 14 months.The effects of nutrient enrichment were analyzedfollowing a BACIPS ANOVA design. The changes innutrient concentration were associated with a significantincrease in diatom density and a decrease inspecies richness and diversity. The additional nutrientload also caused the change in the diatom taxaproportion, favoring motile forms, Nitzschia speciesmainly. The fertilization in La Choza, caused a mild tomoderate effect, indeed not immediate, on the diatomassemblage. These delayed responses of moderateintensity could be related with intrinsic characteristicsof diatom assemblages pre-adapted to nutrient-richenvironments. The rising urbanization and agriculturalactivity in the Pampean plain, may seriously impairthe biodiversity of its rivers if the entrance of nutrientsto these ecosystems is not mitigated.