What is the green one on the pic ?
a) a cage for urban rabbits ?
b) a (clever) trap for a bear - a king of wilderness ?
c) a cover for Rhododendrons protecting them against the sun
Yep, I think you guessed right. It is c). There are already tenths of buds of Rhodos waiting for the Summer. The biggest threat for the bud is the sun while there is frost in the ground and the roots are frosen.
Otherwise it seems that the Rhodos have survived well even though the winter have been extremely cold.