Flooding regime of the Ob river downy willow scrubs (Carici aquatilis-salicetum lapponum Taran 1993, Alnetea glutinosae) for 1979-2016

Syntaxonomical and hydrological characteristic of downy willow ( Salix lapponum ) scrubs spread on the Ob River floodplain within the limits of middle taiga subzone is given. The willow scrubs are studied in Surgut (near Surgut) and Nizhnevartovsk (the Yermakovsky Yogan River lower course) districts of Khanty-Mansi Autonomous Area, Russia. The willow scrubs belong to association Carici aquatilis-Salicetum lapponum Taran 1993 ( Alnetea glutinosae ). They are divided into 2 subassociations: boggy (subass. typicum, var. typicum and Carex lasiocarpa ) and meadow-boggy ( Carici aquatilis-Salicetum lapponum juncetosum filiformis Taran, Tyurin et Dyachenko 2016). Near-Surgut boggy downy willow scrubs (var. Carex lasiocarpa ) are located on peats with thickness 144-164 cm and on height 682-692 cm above Surgut gauge zero. Their yearly flood frequency for 1979-2016 is 51-59%, maximum flood duration - 73-75 days (2007), mean flood duration for years when the willow scrubs were flooded (ever if their lower levels only) is 38-43 days...