ИСТИНА

Beaded streams have channels characterized by round evenly-spaced pools connected by narrow runs and are common low-order fluvial forms throughout Arctic Alaska and Russia and Siberian taiga. The beads have important implications for flow discharge regulation, biota survival and for ecosystems in general by supporting overwintering habitats and biodiversity. There are two main hypotheses of the origin of beaded streams. The first hypothesis, which came from Russian Yakutia in 1927, considered that beads are ancient river pools that were formed when deposited sediment froze. However, the most accepted hypothesis state that beaded streams are a result of ice-wedge degradation. I will compare these two hypotheses based on field studies in Russian Siberia and Northern Alaska in order to explore the formative processes and discuss how beaded channels may respond to changing conditions.