Vascular aquatic plants of the Lower Tisa River (Serbia) – species composition and distribution pattern

Abstract

The Lower Tisa is the 150 river km long section of the river through Serbia, where it runs into the Danube. The survey of vascular aquatic plants in the main channel of the Tisa River was undertaken during the time period 2004-2010. Survey included estimation of basic habitat characteristics (bank structure, sediment type, water flow velocity, water transparency, land use type) and estimation of the occurrence and abundance of plant species in the contiguous survey units along the main channel of the river, which were equal to the river kilometers. Recorded species were mainly estimated as rare, since the conditions found both on the banks and in the water do not favor the development of aquatic or semi aquatic vegetation. Many of hydrophytes do not have established populations in the main channel, but arrive through tributaries or from cut off oxbows during the periods of high water levels. Lateral connectivity interruptions caused by loss of flood plains and bank reinforcements are reflected in low diversity of the sediment material type, medium and high water flow velocity and low water transparency, which restrict growth of hydrophytes. The only observed effect of the longitudinal continuity interruption created by dam is presence of small populations of rooted hydrophytes Potamogeton x fluitans and Stuckenia pectinata found in the upstream section of the river.

Keywords

• running water
• aquatic macrophytes
• habitat parameters
• abundance