Ectomycorrhizal fungi invade the apoplast, but not the symplast. Water movement across the cortex may be through the apoplast or symplast. A layer, of varying thickness, of still air adjacent to a surface such as a leaf.
High winds reduce the thickness of the boundary layer, speeding diffusion of gases.
The living tissue in woody components of trees, forms xylem to the inside, and phloem and bark to the outside. Typically refers to movement of water through plants. Conducting tissue that carries sugars and other chemicals to living tissues in trees. The conducting tissue in trees, comprised mostly of dead cells.