Southeastern Washington and Adjacent Idaho. gI 
tain streams, which, indeed, may be oe with ¢ a more or less 
fragmentary alder community. 
SUBSERE. REFORESTATION OF CUT-OVER AREAS AND 
BURNS 
Since the direction of development is always forward and 
toward the climax community of a region, the removal of the 
plant cover, such as a forest, makes possible the repetition of 
the story of normal succession. This, however, may be consider- 
ably modified and the amount of repetition determined by the 
degree of completeness of the destruction. 
In studying the natural reforestation of the region, it will be 
advantageous to consider first the secondary succession or sub- 
sere after cutting, and afterwards the reéstablishment of forests 
following burns. 
Naturally many of the outlying pine-covered areas were early 
cleared by the settlers and the land used for the cultivation of 
crops. Where small tracts have been allowed to “go back” after 
removing the yellow pine and burning the brush, the first years 
show a rapid growth of shrubs while the intervening spaces are 
dominated largely by prairie species. Opulaster pauciflorus, 
Spiraea corymbosa and other shrubs, which in the denser stands 
have been suppressed by the shade, spring rapidly into dominance, 
while Epiobium angustifolium, Cirsium palousense, Pteridium 
aquilinum pubescens, and Deschampsia spp. mingle with various 
prairie species already designated as occurring in yellow pine 
forests. Among these, yellow pine seedlings grow vigorously 
and the forest finally reéstablishes itself. Of course, repeated 
fires kill the pine seedlings, burn off the shrubs, and favor the 
invasion of prairie plants. Although prairie fires in the Palouse 
Region were never so severe as those of the Great Plains, it is 
probable that they played an important role in preventing the in- 
vasion of conifers into the grass land. 
In most of the more accessible canyons of the mountains, 
lumbering has been carried on and in some places the operation 
of the lumberman has been followed by ground fires. In prac- 
tically all cases, except in the lodgepole region eastward, where 
QI 
