THE FOREST INVADING A PEAT BOG 

 Antagnostic Plant Societies 



I It- re is a typical picture of one phase of the struggle that is 

 constantly going on between different plant societies. The birch 

 lives, supported by willows and alders, have established outposts 

 in the bo<r, and the main forces of the forest are coming up to 

 complete the conquest. The common bog plants are still holding 

 their ground, but their leaves are no longer a healthy green, 

 and their flowers are small and scattered. Evidently they cannot 

 last many more years. Behind this victory of the forest over 

 the bog is a long story concise^ told by the late Prof. Geo. F. 

 Atkinson of Cornell University in the following paragraphs : 



"Many of the peat bogs were once small ponds or lakes. 

 The peat moss and other plants which find shallow water a con- 

 genial place to grow in begin marching out from the edge of the 

 water toward the centre of the pond. The stems of the peat 

 die below and grow above. So in this way they build up a floor 

 or platform in the water. The dead peat now in the water 

 below does not thoroughly rot, as the leaves do in the moist ground 

 of the forest, because the water shuts out the air. The partly 

 dead stems of the moss pile up quite fast in making the platform, 

 which sometimes is entirely composed of peat. Other plants 

 may grow along with the peat. Their dead bodies also help to 

 build up this floor beneath. 



"The army of peat and other water plants continues to march 

 out toward the centre of the pond, though slowly. Finally, in 

 many cases, the line around the shore meets in the centre and the 

 pond is filled up, the floor having been extended entirely across. 

 But they keep on adding each year to the floor, raising it higher 

 and hi'jher. until it is high enough and dry enough for the march- 

 ing armies of the dry land Brasses, shrubs, and trees. At length a 

 forest comes to stand on the floor built across the pond by the 

 peat moss and the other members of its society." First 

 <>f I ' lii n f /,//>. (thin and Company. 



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