FORESTS DESTKOTED BY MAESHES. 83 



forests given rise to the appearance, on the spot or near it, of a 

 morass, but a morass otherwise produced has brought about a 

 destruction of forests. 



Sbot. III. — On the Occasional Destritction of Forests hy the Crectiion of 



Marshes. 



The cases of forests having beea destroyed by the creation of 

 marshes are numerous. There is nothing in this which is otherwise 

 than in accordance with the views of the meteorological effects of 

 forests which have been advanced; but it may be well that this 

 should be shown, and it may be not improper that in doing so the 

 phenomena should be brought under consideration in more than 

 one of the phases which they present. 



I have, ia the preceding section of this chapter, given my explana- 

 tion of the fact communicated to me that in some cases in Eussia 

 the clearing of the portion of a forest by a forest fire, or by a hurri- 

 cane, has been followed by the conversion into a morass of the ground 

 on which it grew ; and I have brought forward other facts suggestive 

 of how it may be that the results followed. But these exhaust' not 

 the means by which morasses are produced in forest land. 



In forests we meet with swamps which appear to have destroyed 

 trees growing on the spot, but which may have been themselves pro- 

 duced by the destruction of other trees through a process in no respect 

 similar to any which have been noticed. 



I submitted the account I have given of the facts communicated to 

 me by my friend in Eussia to an intelligent English engineer who had 

 resided much in the interior of the country, who was a man of careful 

 observation, one who reasoned on what he saw, and one from whom 

 I had received much information in regard to forests in Eussia. He 

 returned my statement with the following annotation : — " In the 

 interior there occasionally occur great hurricanes, tearing aU before 

 them and blowing down large spaces of the forests, laying the trees 

 with their roots attached to them in all directions, and being in many 

 cases far from towns or villages the blown down trees are never 

 taken away, but decay where they have fallen, as I have seen. When 

 the ground is level, the little river is, from the fallen trees, raised in 

 its bed, or, as is often the case, is changed in its course. There is 

 thus always more of the space kept longer under water in the spring 

 than formerly, and during the summer a rank vegetation springs up. 



