Southeastern Washington and Adjacent Idaho. 97 



white fir, tamarack, Douglas fir, and cedar, the thick-barked 

 tamarack suffered least, and often only the trees of this species 

 less than 6-8 inches in diameter were killed. This gave rise to 

 what are apparently nearly pure forests of tamarack ; but in most 

 cases sufficient seed trees of the other species were left to in- 

 sure re-seeding, and at present a new generation of white fir and 

 tamarack are especially prominent. 



Notwithstanding the now open nature of the forest, the ground 

 being covered with the blackened and charred remains of fallen 

 white firs and cedars, many of the smaller tamaracks, though 

 dead, are still standing. The larger ones, often fire scarred, but 

 living, are not usually more than 12-14 inches in diameter. They 

 reach a height of 85-100 feet, and, like the fir, reveal by their 

 high pruning a former forest with a closed canopy. 



On the upper and middle slopes the ground is more or less com- 

 pletely covered by a thin layer of raw humus, consisting mostly 

 of the leaves of the tamarack. Numerous quadrats in various 

 areas revealed a predominance of the seedlings of the white fir, 

 often 20-25 per square meter, while Douglas fir and tamarack 

 were less abundant. In many places the mineral soil was destitute 

 of vegetation, while only a sparse growth represented by Hier- 

 acium albiflorum, Clintonia uni flora, Adenocaulon bicolor, Galium 

 sp., Chimaphila umbellata, Micromeria chamissonis, Pyrola picta, 

 and a few other scattered species occurred elsewhere. 



The severe conditions under which the tree seedlings were 

 growing were shown by the fact that even the oldest, which came 

 in at least three or four years after the fire, did not exceed a 

 height of 15-18 inches. 



Judging from adjoining and unburned forests of a similar com- 

 position it appears that the remaining tamaracks by a spreading 

 of their crowns had considerably increased the shade, the light 

 value often falling to 0.2, and thus offering considerable protec- 

 tion to the tree seedlings. 



Farther down on similar slopes, where the fire left fewer trees 

 standing, both because fewer tamarack trees were present and 

 because the fire was more severe, quite a different stage in repro- 

 duction is to be seen. Here, because of more moisture and the: 



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