Water level effect on herbaceous plant assemblages at an artificial reservoir-Lago Azul State Park, Southern Brazil.

D C Souza,P A A Bueno,R O Bueno,J B Campiolo,L Iwakura,J D Ferreira

doi:10.1590/1519-6984.01513suppl

D C Souza, P A A Bueno + Show 4 more

Open Access

https://doi.org/10.1590/1519-6984.01513suppl

Copy DOI

Abstract

This study presents the effect of water level variation on the assemblages of herbaceous species in Mourão I Reservoir, Lago Azul State Park, Southern Brazil. The structure and distribution of populations was examined in February (dry period) and April (rainy period), 2011, in two transects. These transects started at the forest edge towards the center of the lake. The end of the transect coincided with the end of the plants within the lake. On every two meters along of the transects we sampled a wooden square of 0.25 m(2) for species biomass analysis.The macrophyte stand was composed entirely of emergent species. Considering the periods, most species were less frequent in the rainy period (April), but Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. and Verbena litorales (Kunth.) had their frequency increased during this period, probably due to their resistance. The influence of flood as measured by the NMDS point out that both before and after the flood, there are plots with distinct compositions and biomass. The water level variation affects the dynamics of plant composition and structure in marginal areas of the Reservoir.

Highlights

The operation of hydroelectric directly influences the dynamics of the ecotone formed on the banks of the reservoir, especially the populations of aquatic macrophytes (Thomaz and Bini, 2003)
This study presents the effect of the variation in the water level of the Mourão I Reservoir, at the State Park Lago Azul, Paraná State, on the structure of assemblages of herbaceous species in the region of the reservoir
The vegetation assemblages stand was composed of aquatic macrophytes emergent and land herbaceous

Summary

Introduction

The operation of hydroelectric directly influences the dynamics of the ecotone formed on the banks of the reservoir, especially the populations of aquatic macrophytes (Thomaz and Bini, 2003). Studies in Brazil showed that the period of growth and mortality of aquatic macrophytes are closely related to the variation of water level (Piedade et al, 1991; Junk and Piedade, 1993; Camargo and Esteves, 1996). The region has several protected lateral lakes and flooded areas that serve as refuge for many animal species, which find favorable sites for breeding, feeding, and shelter. Knowledge of this vegetation under the influence of the power plant operating system proved important to identify local trophic relationships and establish management strategies for the conservation unit. This study presents the effect of the variation in the water level of the Mourão I Reservoir, at the State Park Lago Azul, Paraná State, on the structure of assemblages of herbaceous species in the region of the reservoir

Material and Methods

Results and Discussion

Conclusion