Fig. 1From: Relationship between pore structure and gas permeability in poplar (Populus deltoides CL.’55/65’) tension woodTransverse sections of poplar tension wood (a) and opposite wood (b) stained with safranin O and fast green. Unlignified G-layer stained in green-blue in tension wood and lignified cell wall layers stained in red in opposite wood and tension wood. Scale bar (a, b) = 30 μmBack to article page