Woodland habitat is particularly important for invertebrates; small mammals, such as bats and dormice; lower plants, such as fungi, mosses, and lichens; and many bird species.
Mae cynefin coetir yn arbennig o bwysig i infertebratau; mamaliaid bach, megis ystlumod a phathewod; planhigion is, megis ffyngau, mwsogl a chennau; a llawer o rywogaethau o adar.