TITLE:
The Influence of Water Hyacinth Floating Meadows on Limnological Characteristics in Shallow Subtropical Waters
AUTHORS:
Sylvina L. Casco, Romina P. Carnevali, Alicia S.G. Poi, Juan J. Neiff
KEYWORDS:
Eichhornia crassipes, Subtropical Lakes, Temperature, Dissolved Oxygen, Electrical Conductivity, pH
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.13,
June
24,
2014
ABSTRACT: The effects of
free-floating mats of the water hyacinth Eichhornia
crassipes (Mart.) Solms on the limnological characteristics of two lakes
located on the fringing floodplain of the lower Paraná River (27°27'S, 58°55'W)
were studied monthly between April 1998 and April 1999. The mobility of the
free-floating vegetation at both locations prevented continual observation.
Therefore, to carry out the intensive sampling needed for this study, two
experimental ponds (A and B) were filled with water from the Paraná River in
1996. Pond A was designed to reproduce conditions similar to those of lakes
vegetated with water hyacinth. Pond B was designed to recreate the limnological
conditions of these lakes, such as a high concentration of dissolved and fine
particulate organic matter and a peat layer on the bottom; however, pond B
lacked macrophytes. Natural lakes covered with free-floating vegetation were
very similar to pond A, but these water bodies showed a lower temperature,
dissolved oxygen level and pH and a higher conductivity than the non-vegetated
pond. Our results indicated that water hyacinth has a strong local influence on
the limnological conditions in subtropical shallow lakes. Our results may
assist in developing cause-consequence models by demonstrating the relevance
of the effect of thermal damping produced by floating meadows.