<P> In biology, the canopy is the aboveground portion of a plant community or crop, formed by the collection of individual plant crowns . </P> <P> In forest ecology, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms (epiphytes, lianas, arboreal animals, etc .). </P> <P> Sometimes the term canopy is used to refer to the extent of the outer layer of leaves of an individual tree or group of trees . Shade trees normally have a dense canopy that blocks light from lower growing plants . </P>

What kind of plants grow in the canopy layer