Aquatic macrophyte composition in relation to environmental factors of irrigation ponds around Lake Shinji, Shimane, Japan

Abstract

A comparative study of aquatic vegetation of 149 irrigation ponds in the surrounding area of Lake Shinji, Shimane Prefecture, Japan, was done to document the present status of aquatic flora and water chemistry. In addition, influence of 17 environmental factors on the between-pond variation in aquatic macrophyte composition was assessed by using detrended correspondence analysis (DCA). A total of 38 taxa were recorded, and the most frequent taxon was Trapa spp. (> 50~o). Number of taxa per pond ranged from 1 to 14 and mean number was 4.1. Floristic composition was primarily related to variation of the factors such as conductivity, Mg, Ca, Na, alkalinity, altitude, pH and depth. In contrast, no significant correlations were found with total P, PO4-P, transparency, COD, ignition loss of bottom soil, Mn and Fe. Of the 33 significant species associations between 19 species with more than 5Yo frequency occurrence, 28 were positive and the remaining 5 were negative. All of these negative associations involved Trapa spp., and not only water chemistry but some other factors like competition and bottom soil preference were assumed to influence species associations.

Aquatic vegetation as an indicator of littoral habitats and various stages of lake aging in north-eastern Poland

“…The properties indicating water richness, such as COD-KMnO 4 , NO 3 x and PO 4 3x , appear to be important as well, but not as important as the factors associated with the carbonate system, which may be attributed to the small differences in the trophic state of the lakes studied (from slightly eutrophic to eutrophic lakes). Similar observations were also made by others (Jackson and Charles, 1988;Kunii, 1991;Ma¨kela¨et al, 2004).…”

“…It seems, therefore, difficult to compare such data. However, in the case of water, the results of our study confirmed the findings of other authors, who point to the important role of properties associated with the carbonate system in differentiating the habitats of aquatic plant communities (Wiegleb, 1978;Kadono, 1982;Kunii, 1991;Babalonas, 1993a, 1993b;Toivonen and Huttunen, 1995;Vestergaard and Sand-Jensen, 2000). Changes in the carbonate system affect the amount of available inorganic carbon as well as such properties as water hardness, pH, and Ca 2+ and Na + concentrations.…”

Presence of tropical hydrophytes in relation to limnological parameters - a study of two freshwater ponds in Kolkata, India

“…The other type was the occurrence of mixed communities of submerged flora (two to three species) together with floating-leaved (one to two species) and emergent (one to four species) forms (Philipose et al 1970, Gopal 1990. As found in this study, the mixed occurrence of all growth forms has also been widely reported in other tropical and subtropical ponds (Kunii & Maeda 1982, Gopal & Chamanlal 1991, Hussainy 1965, Nasar & Dutta Munshi 1974, Pandey et al 1988, Kunii 1991, Zambrano et al 1999.…”

“…Electrical conductivity -Conductivity has been reported to be an important factor for explaining spatial distribution of aquatic plants (Seddon 1972, Kunii 1991. In the present study, a narrow band of this parameter could be associated with the dominance of C. glomerata (Figure 1d) which is similar to the observation of Biggs & Price (1987).…”

“…Net production of T. natans has also been reported to be positively correlated with nitrogen flux (Tsuchiya & Iwakuma 1993). In a limnological survey of 149 Japanese ponds with Trapa as the dominant flora (56% occurrence) low levels of total phosphorus concentration (0.003 to 0.241 mgl -1 ) was also observed by Kunii (1991). Thus, the preference of low phosphorus level for this species is evident.…”