UDC 626.81:632.5:639.64 Original scientific paper

THEMOSTFREQUENT WEEDS INTHECANAL NETWORK OF THE DUNAV·TISA·DUNAV HYDROSYSTEM

Siobodanka STOJANOVIC·, Ljiljana NIKOLIC and Dejana LAZIe Faculty of Agriculture, Novi Sad Yugoslavia

Stojanovic Slobodanka, Ljiljana Nikolic and Dejana Lazic (200 I): The most frequent weeds in the canal network ofthe Dunav- Tisa-Dunav hydrosystem. Acta herbologica, Vol. 10, No.1, 37-42. The most common aquatic vascular macrophytes in the Dunav­ Tisa-Dunav canal hydrosystem are reviewed. The following segments of the canal network were investigated: Vrbas-, Banatska Palanka­ Novi Becej, Novi Sad-Savino-Selo, Backi Petrovac-Karavukovo, Becej­ , Kikindski kanal, Jegricka, , Plazovic, en, Keres, Krivaja and Tamis. Recent flora of the investigated localities was found to include 40 most frequent plant species classified into 23 families, one of which is a representative of aquatic ferns - Salvinia natans (L.) All. This relatively large number of aquatic weeds is the result of the influence of many abiotic factors (canal age, mud depth, controlled water regimen, etc.), as well as biotic ones. Key words: Dunav-Tisa-Dunav hydrosystem, recent aquatic flora, aquatic weeds

INTRODUCTION

The Dunav-Tisa-Dunav (DTD) hydrosystem is a multivalent canal system connecting waters of Backa and Banat regions. Its character makes it one of the biggest of its kind worldwide (Cu

• Corresponding author: Slobodanka Stojanovic, Faculty ofAgriculture, Trg Dositeja Obradovica 8, Novi Sad 38 ACTA HERBOLOGICA, Vol. 10, No.1, 37-42, 2001. recipience and drainage of waste waters, municipal, industrial and fishpond water supply, transport, recreation, sports and tourism. Its overall length, including natural streams that have been more or less reconstructed, is 960 km, while its navigable length is 664 km. The canal network has 24 regulatory water gates, including the Tisa dam near Novi Becej, 5 safety gates, 16 ship canals, 6 large pumping stations, and 86 bridges (64 road, 21 railway, and one pedestrian) (LIKIC,1998). Considering the great importance of the DTD hydrosystem, aquatic weeds cause harm and enormous damage to its aquatic biotopes, primarily by impeding flow and thus affecting water amount and its potentials (STOJANOVIC et al., 1994). Weed control in the canal network is a complex task demanding knowledge of the recent flora of aquatic phytocoenoses (MITCHELL, 1979; GOPAL, 1982; STOJANOVIC et al., 1996;1997;1998;1999). This paper therefore aims to review the most frequent weed species of the canal network, so as to provide a basis for their control and create possibilities for their biomass utilization.

MATERIAL AND METHODS

Aquatic vascular macrophytes of the DTD canal network, including Vrbas­ Bezdan, Banatska Palanka-Novi Becej, Novi Sad-Savino Selo, Backi Petrovac­ Karavukovo, Becej-Bogojevo, Kikinda Canal, Jegricka, Mostonga, Plazovic, Cik, Keres, Krivaja, and Tamis have been monitored for the past ten years. The collected taxa were determined according to ''The Flora of " (1970-1986), and "The Key to Aquatic Plants" by FELFOLDY (1990). Popular names were given according to CANAK et al. (1978).

RESULTS AND DISCUSSION

A total of 40 most frequent plant species have been found in the canal network within this long-running floristic-phytocoenological survey.

A review of the most frequent DTDcanal weeds

Fam. Salviniaceae Salvinia natans (L.) All. Fam. Nymphaeaceae Nuphar lutea (L.) Sm. Nymphaea alba L. Fam. Ceratophyllaceae Ceratophyllum demersum L. Fam. Ranunculaceae Ranunculus circinatus Sibth. Fam. Polygonaceae Polygonum amphibium L. Rumex hydrolapathum Huds. Slobodanka STANOJEVIC et. al: THE MOST FREQUENT WEEDS 39

Fam. Brassicaceae Roripa amphibia (L.) Bess. Fam, Trapaceae Trapa natans L. Fam, Halorrhagidaceae Myriophyllum spicatum L. Fam. Apiaceae Oenanthe aquatica (L.) Poiret in Lam. Fam.~enyantaceae Nymphoides flava Hill. Fam. Lamiaceae Lycopus europaeus L. Mentha aquatica L. Fam. Butomaceae Butomus umbellatus L. Fam. Alismataceae ALisma plantago-aquatica Gmel. Fam. Hydrocharitaceae Hydrocharis morsus-ranae L. Vallisneria spiralis L. Elodea canadensis Rich Fam. Potamogetonaceae Potamogeton crispus L. Potamogeton fluitans Roth. Potamogeton pectinatus L. Potamogeton perfoLiatus L. Fam, Najadaceae Najas marina L. Fam. Iridaceae Iris pseudoacorus L. Fam. Juncaceae Juncus effusus L. Fam. Cyperaceae Carex pseudocyperus L. Scirpus lacuster L. Heleocharis palustris (L.) R. Br. Bolboschoenus maritimus (L.) Palla Fam. Poaceae Glyceria maxima (Hartm.) Holmbg. Catabrosa aquatica (L.) P. Beauv. Phragmites communis Trin. Fam, Lemnaceae Lemna gibba L. Lemna minor L. 40 ACTA HERBOLOGICA, Vol. 10, No.1, 37-42, 2001.

Lemna trisulca L. Spirodela polyrrhiza (L.) Schleid. Fam. Sparganiaceae Sparganium ramosum Huds. Fam. Typhaceae Typha angustifolia L. Typha latifolia L.

This rather high number of aquatic weeds occurs as a result of the activity of abiotic factors, such as canal age, which stands in relation with mud thickness and water regimen influenced by an impeded water flow at gates and in the canal system, and by the activity of biotic factors, i.e. aquatic plants themselves. Aquatic plants hamper the flow of streams by their rapid propagation, high biomass production and enormous expansion ability. Outside vegetation periods, on the other hand, their deposits intensify microbiological processes that result in rather fast water eutrophication.

CONCLUSION

This survey of aquatic vascular macrophytes of the DTD canal network included the following canals: Vrbas-Bezdan, Banatska Palanka-Novi Becej, Novi Sad-Savino Selo, Backi Petrovac-Karavukovo, Becej-Bogojevo, Kikinda Canal, Jegricka, Mostonga, Plazovic, Cik, Keres, Krivaja and Tamis. Forty most frequent aquatic plants, one of which is Salvinia natans (L.) All., were determined in recent canal flora and they were found to belong to 23 families. This rather high number of aquatic weeds is the result of a number of abiotic factors (canal age, mud thickness, controlled water regimen, etc.) as well as biotic factors. Aquatics in canal ecosystems slow down water flow, impede water supply, cause overnight oxygen deficit and produce considerable organic load in non­ vegetation periods, causing autopollution and mud deposition. Siobodanka STANOJEVIC et. at: THE MOST FREQUENT WEEDS 41

REFERENCES

CANAK, M., PARABUCSKI, S., KOJIC, M. (1978): lIustrovana korovska flora JugosIavije, Matica srpska, 1-440, Novi Sad. CIKIC, E. (1998): Pedeset godina Hidrosistema Dunav - Tisa - Dunav (1947-1997), Vodoprivreda 1-2, str. 3-7, Beograd. FELFOLDY, L. (1990): Visugyi hidrobiologia 18-Kotet-Hinar haterarazo Komiezetveldelmi es Teruletfejlestesi Miniszterium, 1-144. Budapest. GOPAL, B. (1982): Biological and ecological considerations in aquatic weed management, Proceedings EWRS 6th Symposium on Aquatic Weeds, 152-158.

JOSIFOVI(~, M. ed. (1970-1986): Flora Republike Srbije, I-IX, Srpska Akademija nauka i umetnosti, Beograd. L1KIC, B. (1988): Hidrosistem Dunav-Tisa-Dunav juce, danas, sutra, Vodoprivreda 1-2, str. 9-22, Beograd. MITCHELL, D. S. (1979): Assesement of aquatic weed problems, 1. Aquat, Plant Manage 17: 119-21. STOJANOVIC, S., BUTORAC, 8., VUCKOVIC, M., STANKOVIC, Z., ZDERIC, M., KILIBARDA, P., RADAK, U. (1994): Biljni svet kanala Vrbas-Bezdan. Univerzitet u Novom Sadu, Prirodno-rnatematicki fakultet, Institut za biologiju, 1- 110, Novi Sad. STOJANOVIC, S., VUCKOVIC, M., STANKOVIC, Z., ZDERIC, M., KILIBARDA, P. (1996): 0 flori i vegetaciji Jegricke, Edicija Tija voda, Monografija 1,61-67, PCESA, Novi Sad.

STOJANOVIC, S., VUCKOVIC, M., ZDERIC, M., STANKOVIC, Z., KILIBARDA, P., LAZIC, D. (1997): Recentna flora vaskulamih makrofita kanala "Vrbas-Bezdan" i "Banatska Palanka­ Novi Becej" kao pokazatelj ekoloskih karakteristika i kvaliteta vode, Konferencija 0 aktuelnim problemima zastite voda "Zastita voda '97", 376-379, .

STOJANOVIC, S., LAZIC, D. (1998): Pregled vaskulame flore Tamisa sa flomim elementima i zivotnim forrnama, Nas Tamis, naucna monografija, Univerzitet u Novom Sadu, PMF, Institut za geografiju, 75-87, Novi Sad. STOJANOVIC, S., VUCKOVIC, M., NIKOLIC LJ., LAZIC, D. (1998): Biljni svet Mostonge. U: Mostonga i vode zapadne Backe: 44-46, Edicija Tija voda, PCESA, Novi Sad.

STOJANOVIC, S., KILIBARDA, P., ZDERIC, M., NIKOLIC, LJ., LAZIC, D. (1999): Biljni svet kanala Novi Sad-Savino Selo. Eko-Konferencija '99, Monografija I, Novi Sad, 137-142.

Received September 27, 2001 Accepted October 2, 200 I 42 ACTA HERBOLOGICA, Vol. 10, No. 1,37-42,2001.

NAJCESCE KOROVSKE BILJKEU KANALSKOJ MREZIHIDROSISTEMA DUNAV-TISA-DUNAV

Slobodanka STOJANOVIC, Ljiljana NIKOLIC i Dejana LAZIC

Poljoprivredni fakultet, Novi Sad, Jugoslavija

I z v 0 d

U radu je dat pregled najcescih akvaticnih vaskularnih makrofita zastupljenih u kanalskoj mrezi Hidrosistema Dunav-Tisa-Dunav. Proucavanjima su obuhvaceni sledeci kanali: Vrbas-Bezdan, Banatska Palanka-Novi Becej, Novi Sad­ Savino-Selo, Backi Petrovac-Karavukovo, Becej-Bogojevo, Kikindski kanal, Jegricka, Mostonga, Plazovic, cu, Keres, Krivaja i Tamis. U recentnoj flori ispitivanih kanala konstatovano je da se sa najvecorn frekvencijom pojavljuje 40 biljnih vrsta iz 23 familije, od kojih je jedan predstavnik vodenih paprati - Salvinia natans (L.) All. Relativno veliki broj akvaticnih korovskih biljaka rezultat je uticaja mnogih abiotickih faktora (starost kanala, debljina mulja, dirigovani vodni rezim, itd.) kao i biotickih.

Primljeno 27. septembra 200 I. Odobreno 2. oktobra 2001.