Temporal and spatial variation of limnological variables and biomass of different macrophyte species in a Neotropical reservoir (São Paulo - Brazil)

Abstract

AIM: This study reports an investigation of limnological characteristics and aquatic macrophyte occurrence in a neotropical reservoir in order to assess the spatio-temporal variation of water and sediment variables and their influence on plant distribution. METHODS: Macrophytes, water and sediment samples were collected from a Brazilian reservoir in different seasons from four main arms of the reservoir. In total sixteen water-sediment variables were analyzed including N:P ratio and Trophic State Index. The plants were collected using a quadrat sampling procedure and the dry weight per sample was measured. MANOVA was performed to evaluate spatial and temporal variation of environmental variables as well as seasonal biomass differences. To assess the relationship among environmental variables and macrophytes an ordination analysis (using Canonical Correspondence Analysis: CCA) was carried out. RESULTS: The spatial and temporal variation of limnological variables generated a heterogeneous system which supports the presence of different species of macrophyte. pH, dissolved oxygen and sediment composition were important predictors of Polygonum lapathifolium occurrence while nutrients were associated with Eichhornia crassipes and Pistia stratiotes. Inorganic substances were related to biomass variation of Eichhornia azurea and Myriophyllum aquaticum. CONCLUSIONS: The spatial variation of the environmental variables has caused heterogeneity in the reservoir and it may support the occurrence of different species of macrophyte. Limnological variables highlighted in CCA are important to predict the species occurrence and their control in the study area.

Environmental drivers of freshwater macrophyte diversity and community composition in calcareous warm‐water rivers of America and Africa

“…In contrast, there has been quite a substantial macrophyte survey effort in the Neotropics, particularly in South American freshwater systems (e.g. Amaral, Bittrich, Faria, Anderson, & Aona, 2008;Bando, Michelan, Cunha, Figueiredo, & Thomaz, 2015;Bertoli, 1996;Bottino, Calijuri, & Murphy, 2014;Murphy et al, 2003;Neiff, Casco, Mari, Di Rienzo, & Poi, 2014;Rolon & Matchik, 2006;Schneider, Cunhab, Marchese, & Thomaz, 2015;Sousa, Thomaz, & Murphy, 2010Thomaz, Carvalho, Padial, & Kobayashi, 2009;Varandas Martins et al, 2013), although less so in Central America (e.g. Anonymous, 1999;Bonilla-Barbosa, 2004;Crow, 1993;Philbrick & Alejandro, 1995).…”

Distribution of aquatic macrophytes along depth gradients in Lajeado Reservoir, Tocantins River, Brazil

“…It is worth noting that morphometric variables considered in this survey, such as depth and slope, have low predictive value, once floating plants are more affected by wind action, currents, nutrients and fetch (Camargo et al, 2003;Marques-Silva & Thomaz, 2009). They usually proliferate in sheltered sites, lentic and eutrophic systems (Bini et al, 1999;Thomaz & Esteves, 2011;Bottino et al, 2013). They may also thrive among roots and stems of emergent plants in the littoral zone (Marques- Silva & Thomaz, 2009;Thomaz & Esteves, 2011), as commonly observed in Lajeado Reservoir.…”

Richness and distribution of aquatic macrophytes in a subtropical reservoir in São Paulo, Brazil

“…However, the low similarity suggests that the Itupararanga Reservoir is a heterogeneous ecosystem supporting the growth of different species contributing to biological diversity. Despite the low spatial variation of the physical and chemical variables, some recent studies (Cunha & Calijuri, 2011b;Bottino et al, 2013) reported that the main factors related to the spatial heterogeneity of ) at different sampling sites of the Itupararanga Reservoir in two seasons (summer and winter) in 2010. There were no measurements in the sampling sites with absence of macrophytes (in the winter P6, P7 and P9).…”