MICHIGAN ACADEMY OF SCIENCE. 313 



ning stages of forest development make it difficult for the people to 

 develop educationally or otherwise. 



Another tree which occurs in forests of both mixed and pure growth is 

 the hard maple (Acer sacchariim). In the towr ships of Northville and 

 Plymouth, this tree is so dominant in places that secondary species are 

 nearly excluded. The "sugar bush" is common. In other places, often 

 in the same wood lot, it is associated with the beech. Throughout this 

 area the walnut is very abundant, also the cherry (Pruniis serotina), but 

 the predominating tree is hard maple. Zon considers this the climax forest, 

 but this and one other locality, an area of about fourteen square miles in 

 south Brownstown, are the only ones which actually fit into the scheme. 

 A very large portion of this hard maple-beech forest has been cleared 

 away and the land put under cultivation. Comparing now the kind of 

 agriculture, type of farm buildings, and the people, with those of the 

 black oak areas, we find the greatest contrast. Here are woven wire 

 fences and large barns with silos, indicating good conditions for the keep- 

 ing of stock, especially sheep. Corn and other crops requiring good soil 

 can be raised ; the people speak English ; there is the atmosphere of thrift 

 and hospitality, which we find upon the soils from which associations 

 indicating fertility have been removed. 



A third characteristic tree occurring in both mixed and pure associa- 

 tions, is the shag bark hickory (Gary a ovata), south of Trenton, on 

 Slocum's Island. There are portions of these woods which are nearly pure 

 hickory. The wood is well preserved, easily visited, a large portion 

 being set aside as public ground, and is of rare interest. The associated 

 species are Corya alba, C. glabra, C. microcarpa, Quercus alba, and Q. 

 rubra and are present in portions of the wood lot where the stand is 

 mixed. 



The oak-liickory association tends also to form a rather narrow belt 

 of varying width, but often less than one mile wide, along the extreme 

 eastern part of the county along and near the shore; also, along tlie 

 Huron, and to a less extent, along the River Rouge. The total area 

 occupied by this association is not large enough to allow a distinct farm- 

 ing community to develop. 



The sycamore also tends to form stands, both of pure growth, and 

 mixed. The pure growth stands are small, a few hundred feet at most 

 in extent and of recent origin, as if following a clearing. Pure stands 

 of large diameter, suggesting that such stands occurred in the original 

 forest, were not found. The tree seems to have occurred quite generally 

 along with silver maple, elm, and red maple, and other wet land associa- 

 tions, to be described later. This mixed forest affords good evidence, 

 showing the tolerance of the sycamore. In the S. E. 14, S. E. 14, Sec. 22, 



