| الوصف: |
Birch crooked forests, consisting mainly of twisted birch (Betula tortuosa Ledeb.) with patches of downy birch (Betula pubescens Ehrh.) and a single presence of spruce, willow, and aspen are windproof natural communities along the shoreline of Bolshoy Solovetsky Island. They cover the island from the East, West and South with a width of tens to hundreds of meters and only in the North they alternate with pine trees and protect the internal forest phytocenoses from wind loading and windfall. The research aims at revealing the windproof role of birch crooked forests. The work was carried out at 3 points along the shoreline on trial plots, within which transects were laid out perpendicular to the shoreline (a total of 41 transects). Blueberry birch (2 trial plots) and cranberry birch (1 trial plot) forest types were studied. Trial plots and transects, respectively, were laid out in different conditions in terms of coast indentation: in the bayhead of a semi-open bay (trial plot 1), protected from wind action (blind bay end); on a cape of the seashore (trial plot 2), which is exposed to significant wind loading; on a relatively smooth shoreline (trial plot 3). Wind speed was measured at different distances from the shore using the anemometer LV 110. The wind speed and the amplitude of its fluctuations decrease from the shore towards the coastal birch plantations. This change has a constant and irregular character and depends on the properties of the shoreline and the trial area location. The highest wind speed is observed on the cape, somewhat lower on the open shore, and the lowest in the bayhead. In all the studied areas the wind speed rapidly decreases to the minimum, especially in the first tens of meters of birch plantations. The birch crooked forest dampens the wind speed to a minimum at a distance of about 50 m from the shore and protects phytocenoses of the inner part of the island from the wind. |
