on l-'onsl Condi lions m Northwestern Nebraska 57 



A forest lire swept over one of the larger canyons during 

 the season of 1910, so that an excellent opportunity was 

 afforded to investigate some of the phenomena in connection 

 with tliis event, and especially to note some of the more con- 

 spicuous pioneers in the succession after the fire. Practically 

 ail of the pines had been killed over an area of about 640 

 acres. Some of the trees still showed some green leaves at 

 the tops and a few live trees were found in a protected pocket 

 in the bottom of the canyon. Other than these cases the 

 destruction had been absolute. The fire was most destructive 

 on the slopes facing east and northeast. Apparently there was 

 a northeast wind at the time of the fire. The ground was 

 burned clear of vegetation, there being left much ash and 

 charcoal scattered over the surface. Frequently cases were 

 found where the fire had smouldered along for many days in 

 the root system of a tree eventually resulting in the complete 

 destruction of the larger roots, leaving a number of odd holes 

 \\ith reddened Avails that marked the former position of the 

 main roots of some large tree. The surface rock was also 

 exposed in many places standing out in marked contrast as 

 compared with the ground in the unburned forest. 



No seedlings of the pine or other tree could be found in 

 , I une when the examination was made. However, a number of 

 species of herbaceous plants were abundant and there were 

 also numerous cases of new shoot formation from the partially 

 buried shrubs and biennials that had escarped the fire. The 

 most abundant pioneer on all exposures was the Dogbane, 

 Apocynum androsaemifolium. This species is usually more or 

 less scattered over open areas on the slopes. From such spots 

 as this on the border of the burn great quantities of the light 

 seeds were scattered over the exposed soil in the burned area. 

 The bushy individuals had come up in such great abundance 

 as to completely dominate the burned area in June. The Dog- 

 bane behaves here in exactly the way that the Fire Weed 

 covers burned soils in other regions the first year after a 

 forest fire. On all sites, especially where the fire was most 

 severe, the plant covered the ground at the rate of 6 to 25 

 individuals per square yard for wide stretches with its char- 

 acteristic much-branched stems and multitudes of pink flowers. 

 It dominates in exactly the manner of the Fire Weed. Lathrijii* 



