98 REED: MEADOW VEGETATION IN NORTHERN COLORADO 
on the lower parts of the surrounding hills. The vegetation of 
the park forms itself naturally into the following communities: 
sedge moor, willow scrub, meadow, and dry grassland (see Rama- 
ley, 1). The mesophytic portion of the grassland, which is char- 
acterized by meadow grasses, sedges, and flowering herbs closely 
set so as to expose very little bare ground, is here termed meadow. 
It is with the meadow vegetation primarily that the present paper is 
concerned. The meadow association occurs along streams and 
around ponds, lying just above the willow scrub. Itis bordered in 
turn by dry grassland or else by coniferous forest. The width of the 
meadow zone along streams is I-10 m. or more, but there are hill- 
side meadows also, one in particular being about 300 X 600 m. in 
extent. 
ENVIRONMENTAL FACTORS 
The high altitude of Boulder Park and its proximity to the 
snow-covered peaks of the Continental Divide give it a severe 
climate. There is considerable snow in winter and frequent 
showers occur in spring and summer. The annual rainfall is 
thought to be about twenty-eight inches and the mean annual 
temperature 40° F. with a mean for July of about 58° F. The 
maximum temperature known for July is 82° F., and the minimum: 
32° F. Scarcely a week passes without frost, while ice is formed 
frequently in July and August (see Ramaley, 2). 
The soil of the meadows is a loose sandy loam two to ten 
decimeters thick. The subsoil is composed of coarse gravel. 
Determinations of soil moisture and temperature were made each 
season. The results are shown in TaBLEs I and II. 
TABLE I 
SOIL TEMPERATURES AT A DEPTH OF 30 CM. 
July, 1915, average of twenty-three readings, 53:6° F. 
July, 1916, average of fifteen readings, 6 
TABLE II 
SOIL MOISTURE AT DEPTH OF 30 CM. 
July, 1915, average of fourteen determinations, 16.7 per cent. 
July, 1916, average of five determinations, 16.3 per cent. 
By way of comparison it may be stated that the soil tempera- 
ture of the dry grassland societies shows 64° F. for the July average 
