20 BULLETIN &33, XT. S. DEPARTMENT OE AGKICT5LTURE. 



Douglas fir occupies some low, rocky point. The occurrence of 

 Douglas fir seems always to be the result of natural protection from 

 fire, and we may conclude, as in most of the lower lodgepole regions, 

 that Douglas fir originally controlled the situation. 



B.-2: Nebraska sandhills. — Because of the marked success of the 

 planting of yellow pine and jack pine {Pinus banlcsiana) in the Ne- 

 braska sandhills, it has been deemed advisable to observe to what 

 extent the conditions here differ from those of the yellow pine type 

 in the mountains. Since the establishment of the Halsey Nursery 

 in 1903, temperature and precipitation records have been secured in 

 a river-bottom situation (H-l). In October, 1918, an additional 

 primary station (H-2) was established on the hills 80 or 90 feet higher 

 than the river bottom, on a gentle northerly slope. A station (H-3) 

 for the observation of soil temperatures on a steep southeasterly 

 slope was also installed only 200 to 300 feet from H-2. (See PL VII, 



In considering the conditions shown by the records for these stations 

 it should be borne in mind that the locality does not produce yellow 

 pine naturally, and that no success has been had from direct seeding. 

 This may be due to the very sandy soil as much as to any atmospheric 

 conditions observed. The latter, apparently, are favorable for a 

 very high growth rate of established trees. 



L-l: Lake Moraine Basin spruce. — Elevation, 10,265 feet; aspect, 

 southeast; slope, about 20 per cent. This station is next to the 

 highest in the Pikes Peak series. It is operated by the officials of 

 the city water department of Colorado Springs in cooperation with 

 the Weather Bureau, and the record of precipitation and air tempera- 

 tures has been obtained for 24 years. This site is on a gentle slope 

 not far from the west bank of Lake Moraine, 20 feet above the water 

 and just outside a thick clump of aspen. (See PL VII, fig. 2.) The 

 body of water probably moclifies temperature extremes to a slight 

 extent. The station is not protected by forest, for this consists only 

 of scattered specimens of limber pine, 4 to 8 feet high, which followed 

 a destructive fire 60 "years ago. Some protection from winter wind 

 is furnished by the steep hill to the northwest. 



Is-2: Lea dville flat spruce. — Elevation, 10,248 feet; aspect, south- 

 westerly; slope, 5 to 10 per cent. The surroundings of this station 

 are on the west, an almost flat bench sloping verv gradually to the 

 Arkansas River, 3 miles away, and on the east the higher mountains. 

 The station is near the top of a ridge within the town of Leadville. 

 Most of the ground outside the town is clothed with a young, some- 

 what open growth of lodgepole pine, which apparently has replaced 

 the virgin forest since the first mining activity in this region dis- 

 turbed the natural conditions. This, however, has not been closely 

 invesl [gated. 



The most striking conditions of the locality are the seven 4 wind 

 exposure afforded by the high elevation and the free sweep over a 

 broad basin to the west, and i be apparent poverty of the soil, which is 

 composed of a gravelly sand. This soil, which is of the general char- 

 acter often chosen by Lodgepole, may account for the openness of the 

 stands and tin 1 no: too vigorous growth. On the other hand, open- 

 nr of the stands may he due to artificial factors, such a- smelter 

 fumes, which have been fatal to some of the hill forests nearby. 



