ISSN 1067-4136, Russian Journal of Ecology, 2006, Vol. 37, No. 3, pp. 147–151. © Pleiades Publishing, Inc., 2006. Original Russian Text © V.V. Kurilenko, N.G. Osmolovskaya, 2006, published in Ekologiya, 2006, No. 3, pp. 163–167.
Ecological–Biogeochemical Role of Macrophytes in Aquatic Ecosystems of Urbanized Territories (An Example of Small Water Bodies of St. Petersburg) V. V. Kurilenko and N. G. Osmolovskaya St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 1999034 Russia; e-mail:
[email protected] Received May 14, 2005
Abstract—The accumulation of heavy metals (Fe, Mn, Zn, Cu, Cr, Ni, Pb, Cd) and biogenic elements (P, S, K, Ca, Na) in leaves has been studied in macrophytes of different ecological groups growing in small water bodies of St. Petersburg. The ecogeological and biogeochemical role of macrophytes in the water–aquatic plants–bottom sediments system and their contribution to the stability of aquatic ecosystem functioning under conditions of a megalopolis are considered. Prospects for using macrophytes for bioindication and phytoremediation of polluted aquatic ecosystems are discussed. DOI: 10.1134/S1067413606030015 Key words: macrophytes, heavy metals, aquatic ecosystems, biogeochemical indication, ecogeology.
Aquatic ecosystems of urbanized territories, being the terminal link of pollutant migration, are exposed to a strong anthropogenic impact that manifests itself, in particular, in the increased input of heavy metals and biogenic elements into these ecosystems. The biogeochemical cycle of elements, which develops in an aquatic ecosystem under the influence of redox conditions existing in it, depends primarily on the balanced state of ecogeological processes in the aquatic environment–biota–bottom sediments system. Disturbances of this balance under the effects of water pollution may make the aquatic ecosystem incapable of water purification and self-recovery. Among biotic components of aquatic ecosystems, higher aquatic plants (macrophytes) hold a special place as the main factor of the formation and regulation of water quality and oxygen content in natural water bodies (Moore and Ramamoorthy, 1987; Lychagina et al., 1998). The specific ecogeological role of macrophytes in aquatic ecosystems is determined primarily by their high assimilation potential, due to which they function as the main producers of organic matter, which eventually precipitates and forms bottom sediments. Another ecologically important feature of macrophytes is their ability to accumulate biogenic elements and ballast or toxic substances, including heavy metals (HMs), proportionally to their concentration in the environment (Dikieva and Petrova, 1983; Burdin and Zolotukhina, 1998; Lychagina et al., 1998). This property has largely determined increasing interest in macrophytes as objects of biogeochemical indication and biomonitoring of pollution of natural aquatic ecosys-
tems (Nikanorov and Zhulidov, 1991; Lychagina et al., 1998; Osmolovskaia and Kurilenko, 2001; Panin and Sviderskii, 2001; Kurilenko et al., 2002), as well as potential agents in technologies for phytoremediation of wastewaters and bottom sediments (Salt et al., 1998; Galiulin and Galiulina, 1999). At the same time, many issues related to the contribution of macrophytes to self-regulation and selfrecovery of ecosystems in inland water bodies located in urbanized areas have been poorly studied. For this reason, this paper deals with the ecological–biogeochemical aspects of the bioaccumulating activity of macrophytes belonging to different ecomorphological groups in small water bodies of St. Petersburg. We analyzed their ecogeological and biogeochemical role in providing for the tolerance of aquatic ecosystems to technogenic load and estimated the potential and prospects for employing individual macrophyte species in phytoindication and phytoremediation of polluted waters. MATERIAL AND METHODS We studied macrophytes typical of small water bodies of St. Petersburg and belonging to three ecological groups: riparian–aquatic hygrophytes (reed Phragmites communis Trin. and cattail Typha latifolia L.), rooted hydrophytes with floating leaves (pondweed Potamogeton natans L.), and completely submerged hydatophytes (Canadian waterweed Elodea canadensis Rich. et Michx. and hornwort Ceratophyllum demersum L.).
147
148
KURILENKO, OSMOLOVSKAYA
Table 1. Concentrations of heavy metals in leaves of macrophytes from inland water bodies of St. Petersburg (above the line) and the reference lake (below the line), mg/kg dry phytomass Plant
Fe
Mn
Zn
Cu
Cr
Ni
Pb
Cd
421–8800 -----------------------140
1170–4930 --------------------------52
14–61 --------------16
9–29 -----------5
3.4–12.0 --------------------1.5
4.4–6.3 -----------------1.0
1.3–27.4 --------------------
