Precipitation retention by birch-spruce young forest canopy in middle taiga of Komi Republic

The paper highlights 10-year-long study results on rainfall retention by the canopy of secondary birch-spruce young stand in the middle taiga subzone of the Komi Republic. The average rain retention by the canopy of a birch-spruce young forest in relation to an open area is determined. The studied young growth keeps less precipitation volumes than spruce forests and medium-aged deciduous stands of the middle taiga subzone. We have viewed a number of factors controlling precipitation retention. Spruce crowns keep 28 %, birch keeps 13 % of exposed place bulk precipitation. The largest precipitation volumes in the birch-spruce young growth fall through the inter-crown spaces — about 95 % of exposed place bulk precipitation. The rain retention by the canopy of the studied young forest is characterized by a high variability. We have assessed the seasonal and annual dynamics of rainfall retention. Within the seasonal dynamics, the periods from June to early August and from end September to October have a decrease and from August to September there is an increase in the retention value for the studied birch-spruce young growth. There exists a certain link between precipitation retention by the canopy of the studied young forest and exposed area bulk precipitation. This link is expressive for spruce crowns compared with birch crowns. The 10-year-old birch-spruce wood intercepts less rainfall than at the age of 20. However, the 10-year-long study period does not show any clear dynamics of retention increase. The data obtained can be used in forest hydrology to assess impacts of forest harvesting on water-regulating properties of taiga forests.