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are perhaps more conspicuous as pioneers in northwestern 

 Connecticut than elsewhere. The paper birch {Betula alba 

 papyrifera), also, is not an infrequent pioneer in Litchfield 

 County and along the trap ridges toward the north, but is rare 

 near the coast. The most striking departure, however, from 

 any type of succession heretofore described is seen where the 

 pioneer tree is the white pine {Pinus Strohiis). The white pine 

 is widely distributed throughout the state, but its ecological 

 importance varies. Over much of southwestern Connecticut it 

 is so uncommon as to be a negligible factor as regards its influence 

 on succession ; and while frequent enough in the southern part of 

 the central lowland it usually grows scattered and intermixed 

 with other trees. But in parts of northern and eastern Con- 

 necticut the white pine predominates over considerable areas and 

 is a common pioneer in abandoned fields and cut-over tracts. 

 Where white pine comes in strongly — frequently forming, as it 

 does, nearly pure stands — the oak-hickory stage in the succession 

 is often completely eliminated. There may thus be only two 

 tree stages, pine remaining dominant until largely superseded 

 by the more tolerant species of the climax forest. The white 

 pine may even be represented in this ultim^ate forest, in this 

 respect differing from any other pioneer tree. The undergrowth 

 in evergreen, coniferous forests is much sparser than that of 

 deciduous forests, owing to the dry carpet of needles with which 

 the ground is littered. But practically all the shrubs and herbs 

 characteristic of oak-hickory forests are to be found in many 

 white pine forests. On the whole, therefore, it seems appropriate 

 to regard such forests as ecologically equivalent to the oak- 

 hickory forests developed elsewhere. 



Sheffield Scientific School of Yale University 



