 The terrestrial environment can be regarded as two major vegetation zones, one near the coast dominated by Sitka spruce ("Picea sitchensis"), and the other dominated by western hemlock ("Tsuga heterophylla") and Douglas fir ("Pseudotsuga menziesii").Western hemlock often grows in the shade under Douglas fir.Other major tree species in the forest are western red cedar ("Thuja plicata"), red alder ("Alnus rubra"), and bigleaf maple ("Acer macrophyllum").