Taxonomical and ecological characteristics of the desmids placoderms in reservoir: analyzing the spatial and temporal distribution

Sirlene Aparecida Felisberto,Liliana Rodrigues,Helivânia Sardinha Dos Santos

doi:10.1590/s2179-975x2014000400007

Abstract

AIM: This study aimed to evaluate the influence of river-dam axis and abiotic factors on the composition of Closteriaceae, Gonatozygaceae, Mesotaeniaceae and Peniaceae in a tropical reservoir METHODS: Water samples for physical, chemical and periphyton analysis were collected in April and August 2002 in different regions along the axis of the river-dam of Rosana Reservoir, River Basin Paranapanema. The substrates collected, always in the litoranea region, were petioles of Eichhornia azurea (Swartz) Kunth. To examine the relationship of abiotic variables with reservoir zones and between the floristic composition of desmids, we used principal component analysis (PCA) and canonical correspondence analysis (CCA RESULTS: The results of the PCA explained 81.3% of the total variability in the first two axes. In the first axis, the variables of conductivity, water temperature and the pH were related to the sampling regions of April with higher values, while for the month of August, nitrate, total phosphorus and dissolved oxygen showed higher values. We identified 20 taxa, distributed in the genera Closterium (14), Gonatozygon (4), Netrium (1) and Penium (1). Spatially, the higher taxa were recorded in the lacustrine region for both collection periods. The canonical correspondence analysis (CCA) summarized 62.2% of total data variability of taxa in the first two axes, and in August, Closterium incurvum Brébisson, C. cornu Ehrenberg ex Ralfs and Gonatozygon monotaenium De Bary, were related to higher values of turbidity and nitrate to the lacustrine and intermediate regions CONCLUSION: Thus, the formation of groups was due to the regions along the longitudinal axis, then the seasonal period, which must be related to the low current velocity, the higher values of temperature and the water transparency, especially in late summer

Highlights

Reservoirs can be described as a complex network between organisms and their physical and chemical environment, resulting from permanent responses to climatic forces functions and effects produced by manipulation of the system at the dam (Tundisi, 1999)
The Zygnemaphyceae, a relevant group in aquatic environments, with high morphological diversity compared to the other groups of green algae, comprise a large proportion of taxa in periphytic algal community
The Rosana Reservoir, whose hydroelectric was inaugurated in 1987, is situated in the basin of the Paranapanema river, which forms the border between the states of São Paulo and Paraná, between the coordinates, 22° 36’ S and 52° 50’ W (Figure 1)

Summary

Introduction

Reservoirs can be described as a complex network between organisms and their physical and chemical environment, resulting from permanent responses to climatic forces functions and effects produced by manipulation of the system at the dam (Tundisi, 1999). Studies show that the changes of physical and chemical parameters, associated, especially the change in the hydrological cycle, have a dominance of control between different species, and the rapid disappearance of phycoperiphyton in certain seasons (O’Reilly, 2006), especially during the filling phase of the reservoir, when the river is going to be altered (Felisberto et al, 2001; Felisberto and Rodrigues, 2002). The Zygnemaphyceae, a relevant group in aquatic environments, with high morphological diversity compared to the other groups of green algae, comprise a large proportion of taxa in periphytic algal community

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Results