62 
FRANCIS RAM ALE Y 
At very high altitudes there can be no doubt that the drying effect of winter 
winds and the heavy snows are important in preventing forest development. 
Plant Communities of Lake Shores 
Types of Zonation 
Great similarity exists in the shore vegetation of the various lakes 
studied. It is convenient, as already suggested, to separate subalpine and 
alpine life-zones by an arbitrary datum of 11,500 feet altitude. There is, 
however, no sharp difference in vegetation immediately below and above this 
line, yet it is possible to distinguish a subalpine and an alpine type of lake. 
Fig. 4. One of the larger Forest Lakes (altitude 10,800 feet), showing coniferous 
orest of Engelmann spruce coming down close to the lake edge. There has been very 
little infilling either through wash from the slopes or through accumulation of plant remains. 
At the left there is a narrow fringe of moss moor; on the shore opposite the observer a 
considerable amount of meadow moor has developed in the lower places close to shore. 
Photograph in early June by Dr. W. W. Robbins. 
The former only will be considered in the present paper. So far as the 
writer is able to do so, he will use a terminology consonant with that pro- 
posed by Nichols (4). Plant nomenclature will be that of Rydberg (12). 
Subalpine lakes are typically surrounded by Engelmann spruce forest 
in which subalpine fir (Abies lasiocarpa) and lodgepole pine (Pinus mur- 
rayana) may occur in small amount. Aspens (Populus tremuloides) are 
occasionally present, but they belong rather to the montane zone where 
they are very abundant. On the eastern wind-swept shores of lakes the 
forest is often made up largely of limber pines (Apinus flexilis), the trees 
«5cattered with intervening open spaces. 
