182 ANNUAL EEPOETS OF DEPARTMENT OP AGRICULTURE. 



or otherwise poor soil; that open-grown trees produce larger crops 

 of cones, larger yields of good seed per bushel of cones, and larger 

 2-year-old seedlings than do forest-grown trees. 



The numerous experiments with methods and seasons for reforesta- 

 tion have, without exception, added evidence to the advisability of 

 planting nursery stock. As to the kind of stock to use, experimental 

 results secured from planting seedling stock on the west slope of 

 the Cascades, where favorable moisture conditions prevail, have 

 brought out facts which may have a far-reaching effect in the Pacific 

 Northwest. They indicate that western white-pine and yellow-pine 

 seedling stock, as a whole, survive better than transplant stock. With 

 western larch stock a larger number of transplants than of seedlings 

 survived, jet the cost for each surviving tree was lower for seedlings 

 than for transplants. Approximately 6,000 acres of old plantations 

 in the Pacific Northwest were examined to ascertain, as a guide for 

 future planting in the region, what methods, sites, character of stock, 

 and seasons of planting have given the best results. A continued 

 study of old burns of Douglas fir west of the Cascades to discover 

 imder what conditions natural reproduction takes place showed that 

 when a mature stand of timber is burned a stand of young growth 

 springs up from the seed stored in the litter and duff, unless the 

 fire is so severe that the litter and duff are consumed ; that a young 

 seed-bearing stand produces a more scattering stand of young growth 

 following a fire, due to less litter and duff and less seed on the 

 ground; that white pine follows repeated burns better than other 

 species because its seed remains fertile in the ground longer and 

 because it begins to bear seed at a much younger age than such asso- 

 ciates as hemlock, Douglas fir, and cedar; that a burned forest is 

 normally followed by the same species that made up the original 

 forest, but with a varying representation, determined by the seeding 

 conditions before the fire; that exposed dry slopes are always par- 

 tially or entirely denuded as a result both of the drier conditions at 

 the time of the fire and of the loss of seedlings after germination by 

 drought ; and that germination is greatest the first year after the fire, 

 but scattering germination takes place for several years. Study of 

 the effect of forest cover upon streamflow and erosion at the Wagon 

 Wheel Gap Experiment Station was continued. In the study of the 

 climatic characteristics of forest types numerous observations were 

 conducted in Colorado, California, Idaho, and elsewhere. The ex- 

 tension of snow-scale observations to all Wyoming Forests, in coop- 

 eration with the Weather Bureau, will materially help this study. 



Investigations in seeding ranges to cultivated forage plants were 

 limited, as in the previous year, to intensive experiments with hardy 

 varieties of Russian alfalfas and with some 25 species of native range 

 plants. The object is to find, if possible, some valuable forage plant 

 which will thrive where climatic and soil conditions are not favor- 

 able to the present species. A small amount of time was devoted 

 to a continuation of the studies with cultivated species under open 

 range conditions. 



Deferred and rotation grazing investigations were continued at 

 the Utah Experiment Station, on the Eldorado and Coconino For- 

 ests, and to a minor extent in many places elsewhere. The funda- 

 mental principles are that revegetation is helped by grazing after seed 

 maturity, but continued grazing prior to seed maturity weakens the 



