SAND DUNES OF COOS BAY 239 



water in these ponds is fresh and they as well as their borders and 

 the meadows possess a remarkably rich and interesting flora. 

 Nymphaea polysepala is abundant on some of the ponds, while 

 Salix sUchennis is to be found on their margins. 



The destruction of the forests here by shifting sand is all the 

 more remarkable when it is considered that this is a region of 

 excessive humidity and that the coast is bathed almost contin- 

 uously by the fogs which are produced when the warm moisture- 

 laden winds strike the cooler land. During August and Septem- 

 ber T estimated that less than 20% of the time was dry enough, 

 with the wind in the right direction and strong enough, to produce 

 any visible movement of the sand particles. 



When the wind is strong from the west, however, on a dry day, 

 the movement of the sand is tremendous, covering a 6-inch log 

 in the lee of a dune in less than an hour, and across the crests of 

 the dunes coming with such force as to be almost unbearable to 

 the uncovered face. Curious etchings are produced on sticks 

 and timbers exposed to this blast, the usual effect being the 

 eventual wearing away of all parts except the knots. On up- 

 right sticks, particularly severe wind storms are registered by 

 transverse fuiTows, which indicated the level of the sand at the 

 time of the storm, as the most effective work of the sand seems to 

 be on or close to the level of the ground. 



The forests of this region l^elong to the Humid Transition 

 type and consist mainly of Douglas fir (Pseudotsuga iaxifolia), 

 Sitka spruce (Picea sitchensis), Port Orford cedar {Chamaecy parts 

 lawsoniana), Western Red cedar {Thuya plicata), while the West- 

 ern hemlock (Tsuga heterophylla) , common inland is rarely seen 

 on the dune sands of either past or recent origin. On the other 

 hand the shore pine {Pinus contorta) entirely absent inland, is 

 confined here to dune sand soil, and in some of the older depres- 

 sions in the dune area, almost pure stands of it are to be found, 

 and everywhere that the sand remains undisturbed for a few years 

 dense thickets of the shore pine spring up. Some of these bear 

 cones while they are still less than 5 feet tall. 



Within the dune area the forests exist now only in patches, 

 almost always in depressions, or in "ravines" formed by adjacent 



THE PLANT WORI-D, VOL. 17, NO. S, 1014 



/- 



