Pohyb a bilance říčního dřeva ve vodních tocích/Transport and Budgeting of Large Wood in River Channels

Abstract

Large wood in streams and rivers has become a functional component of lotic ecosystems since the 1970’s pioneering studies in the USA. Large wood has diverse positive roles in channel hydraulics, hydrology, sediment transport, geomorphology, habitat availability and the structure and abundance of aquatic fauna and flora. In contrast to these positive ecological effects, large wood is also recognized as a contributing factor in flood hazard, river navigation problems and adverse effects on the culvert, weir and dam hydraulic structures. This paper focuses on wood dynamics in rivers, with special emphasis on wood transport and budgets. Case studies from the Dyje, Morava and Lužnice rivers are presented herein; and these illustrate the processes of wood recruitment from riparian vegetation, the conditions and distances for large wood transport and the annual wood budgets. Transport (mobility) and deposition of wood in river channels is a complex process governed by channel geomorphology, hydrological regimen, large wood properties, character and distribution of riparian vegetation and anthropogenic influences.

Keywords

• river
• lotic ecosystem
• large wood
• wood budgeting
• wood transport