slash was not burned, were nearly always followed by 

 severe fires, which not only killed all young growth, 

 hut destroyed every seed tree the lumbermen had left. 



The dominating trees on high land in the pine belt 

 from the Atlantic coast to the Red River Valley an- 

 the white pine and the Norway pine, the whites gen- 

 erally occupying the heavier and the Norways the 

 lighter soils, but it takes nature a long time to re- 

 plant a pine forest. 



The usual order is this: After a fire a thicket of 

 poplars, birches and brush or jack pines springs up, 

 because these species are nearly always the first ones 

 to occupy vacant ground. They are squatters who on 

 account of regular and abundant seed production and 

 distribution get there first. 



As time goes on, the white pines and Norways 

 gradually come in. Poplars, birches and jacks are 

 comparatively short-lived. In the course of years, 

 when the poplars, birches and jack pines are dying 

 of old age, the white pines and Norways still in their 

 youth, overtop them all and take their place; but the 

 process may take a hundred years. 



In swamps, if they are not too wet, the black spruce 

 or the tamarack is king, and on high elevations or on 

 thin soil, as on Isle Royale and the high ridges of 

 New England, white spruce and balsam will form the 

 final forest, while in large regions of northeastern 

 Minnesota it seems to be a free-for-all fight for all 

 northern trees, even including the sugar maple. 



It is a curious fact that wild plants have their fat 

 years and lean years in seed and fruit production just 

 as do cultivated crops. The year of 1910 was a year of 



27 



