Competitive interactions between Salvinia auriculata Aubl., Limnobium laevigatum (Humb. and Bonpl. ex Willd.) Heine, and other free-floating aquatic macrophytes under varying nutrient availability

Abstract

Competitive interrelationships between Salvinia auriculata Aubl. and Limnobium laevigatum (Humb. and Bonpl. ex Willd.) Heine, in combination with additional Brazilian free-floating aquatic macrophyte species, were studied using the De Wit replacement series method, under conditions of varying nutrient availability. The relative competitive success, measured as biomass production, relative yield total, and aggressivity, of the two target species with each other, with Pistia stratiotes, and (individually) with either Salvinia minima or Lemna minor, was determined in a series of five glasshouse experiments. The competitiveness of three free-floating species relative to S. auriculata was ranked as L. minor > P. stratiotes = L. laevigatum; and relative to L. laevigatum as P. stratiotes > S. auriculata > S. minima. The findings support observations in the literature on the co-existence of these species in Brazilian waterbodies.