Seasonal Distribution of Chemical Elements in Alisma plantago-aquaticaL. and Sagittaria sagittifoliaL.

Abstract

Numerous studies have been carried out on the contents of major and trace elements in various life forms of many aquatic plant species (Dikieva and Petrova, 1983; Smirnova, 1987; Bosserman, 1985). However, the corresponding data are still insufficient, as they are of special interest to biologists, ecologists, and specialists of nature conservation and environmental protection agencies. Today, data on the contents of trace elements (most heavy metals belong to this category) in aquatic plants appear to be especially important. The purpose of this work was to study the seasonal dynamics of chemical element distribution in higher semiaquatic plants, which are common in the shoals of fresh water bodies. Studies were performed on common water plantain ( Alisma plantago-aquatica L.) and arrowhead ( Sagittaria sagittifolia L.), species whose trace element composition is poorly known. The samples of plants jointly growing 125 m away from the shoreline were taken on the low left bank of the Mologa reach of Rybinsk Reservoir, opposite the village of Glebovo. Whole plants were dug out, processed as described previously (Mikryakova, 1997), and individually analyzed for the contents of eight elements using an AAS-3 atomic absorption spectrophotometer. Twenty plants of each species were taken on each observation date to determine fresh and dry weights of ten whole plants and, simultaneously, the aboveground and underground parts of the other ten plants. The ab oveground parts included either leaves or, at later stages, leaves and flower stalks; the underground parts included the root system with shortened rhizomes in water plantain and with stolons and tubers in arrowhead.