UElNDKKli CUA/l.XC 1 .\ V KSTIGATIONS IN ALASKA 



19 



As to «roneral coiKlitioiis, tlu' cliinato is considered more moderate in 

 the KusUoUwini River valloy to the south, and in tlio Kohuk River 

 valley above the Aictic Circle, than in the reji'ions lyin<: between. 

 ]\Iuch lower winter teinpei'atiires prevail in the far interior ai-eas 

 than in the coast belt, but the hij:hei- winter temperatures of the 

 coast re«rion are otl'set by the <:reatei- humidity and prevalence of 

 wind. 



SEASONAL VARIATIONS 



Seasonal variations also have an inii')0i-ant boarinfr on reindeer 

 <irazin<i'. The sunnuer fora<ie crop nuiy be <:ivatly decreased by a 

 backward season or increased by favt)ral)le conditions. Thus there 

 are poor feedin<:- ^-easons and there are <i()od ones, each in turn being 

 clearly rellected in the condition of tiie jirazing aninud. ^"ariation 

 in the advances of the spring season is a problem at fawning time. 

 Under very late conditions greater care must be taken foi' the pro- 

 tection of the newborn fawns, which often come very early in Alaska. 

 Although reindeer fawns are remarkably hardy and capable of with- 

 stantling the ordinai'v vicissitudes of climate, yet exti'eme conditions 

 sometimes result in heavy losses unless precautions are taken. 



Perhaps most imi)ortant of all is the efl'ect that the varied seasons 

 have on the fly pest and consecpiently on the reindeer. During a 

 prevailing cloudy and rainy season, as experienced in 1922. the 

 number of warble Hies is greatly reduced and in some sections they 

 may almost disappear. lender such conditions the reindeer are able 

 to graze unmole.-<ted. 



SOIL CONDITIONS IN ALASKA 



Soil conditions are an important consideration in the selection of 

 a range, chiefly as inHuencing plant growth, especially lichens. 

 AVithin the three main ground tyi)es — dry tundra, wet tundra, and 

 I'ocky areas — are various kinds of soils, the one predominating on 

 tundra areas varying between a black sandy loam and a sand}' clay 

 loam over a blue clay subsoil. The tundra soils are rich in humus or 

 decayed vegetation and often a])])roach a heavy peaty nature. The 

 rocky areas are chiefly of gravelly sandstone soil and (pmi'tz to jagged 

 limestone, in some places volcanic. On the coast range permanent 

 frost occurs 1 to 3 feet below the surface, and in some sections, as 

 at Kotzebue Sound, Wainwright. and Barrow, solid ice is frequently 

 found inmiediately along the coast at a depth of 2 to 3 feet. 



A FORAGE FACTOR 



Lichens vary considerably in their habitat requirements. Some 

 prefer rocks or stones, some the bark of trees, some the soil, and 

 others the mosses, decayed herbaceous vegetation, decayed wood, or 

 shrubs. Again, some prefer a sandstone rock, others a limestone or 

 Cjuartz. Of lichens which grow on the ground, some prefer moist 

 l^eaty soil, some a calcareous soil, some silicious. some argillaceous, 

 and some a hardened mud. Thus the soil and ground conditions 

 determine in a measure the lichen cover and control protectiA^e man- 

 agement of the forage type. In Alaska the best lichen growth for 



