378 STATE HORTICULTURAL SOCIETY. 



for by the state governments. Hence the propriety of our local weather 

 service, and in their work they require the assistance of, and can be aided 

 by, every intelligent person. It is only by supplementing more general 

 studies, by study in small regions, that we can now expect to make much 

 advance in the knowledge of local storms, and these are of paramount im- 

 portance to our farmers. 



We can now perhaps see why there is such a general disagreement as to 

 the influence of forests on climate. The chief effects being local in character 

 they would be most appreciable when the local conditions are most favorable. 

 For instance when the conditions were such that abundant moisture is gen- 

 erally present, the play of the forests would be subordinate. This is the condi- 

 tion of things on the Scandinavian peninsula, surrounded as it is on nearly 

 all sides, and nowhere distant from large bodies of water. The clearing of the 

 entire peninsula of forests would make but little difference in the supply of 

 moisture. But in the continental position of Germany, especially more in- 

 land, the supply of moisture is less abundant, the change of temperature 

 more excessive, and the conservative action of forests is more important. 

 Again, the action of the forests would differ with latitude. In the tropics 

 generally the greater uniformity of weather and the more extensive character 

 of weather changes would make the covering of the soil of only very local 

 importance, while in high latitudes, the slight variation in moisture and the 

 general protection of the ground with snow would also tend to lessen the 

 distinctive effects of forests. 



It is only in middle latitudes that the effects would be important, and it is 

 in continental positions that they would become most conspicuous. Michi- 

 gan is in middle latitude, and she is well in the interior of a great continent. 

 We may expect that she will prove to be quite as sensitive to the removal of 

 her forest clothing as is Germany; and there is another feature of Michigan 

 which may make us look forward with anxiety to her total disforesting. 

 Considerable parts of central Michigan have a sandy soil; they are the so- 

 calkd "pine barrens." They have the reputation of not being valuable for 

 cultivation. What will they be when timber growth has been removed which 

 now holds the sands together and protects them from the direct drying rays of 

 the sun? There is some occasion for fear that their value may then become 

 less than zero ; that while they are now not without use, they may then, 

 become a menace 



Mark W. Harrington. 



Feb. 4, 1888. 



