BIG SPRING PRAIRIE. 95 
BRIEF SUMMARY OF FACTS IN REGARD TO BIG SPRING 
PRAIRIE 
1, Big Spring Prairie is a peculiar marsh area, 
when compared with other drained marshes of the 
state. 
2. This prairie was most probably a portion of a 
preglacial drainage valley, and without doubt, a post 
glacial lake. 
3. The water content and capacity of the soil of 
this prairie is above the average. This fact accounts 
for the striking lagging behind of effects in regard to 
plant life. 
4. The low temperature of the soil water ac- 
counts for this prairie’s marking the southern limit for 
the range of Betula pumila in Ohio. 
5. Artificial drainage has considerably lowered 
the general level of the prairie. Occasional deepening 
of the ditches will be needed on this account. 
In the drainage of other marsh areas, this lowering 
of the general level must be taken into account. 
There must be sufficient fallin the outlet ditches, not 
only for proper immediate drainage but for drainage 
in the future when the soil has settled. 
6. Few ridge species of plants ever gain a foothold 
upon the prairie. 
7. Direction of prevailing winds in connection 
with location of any given area, as along eastern or 
western borders of same; determines largely the num- 
ber of species upon it. 
8. A dense sod tends to prevent the encroachment 
of other forms of vegetation, especially tree seedlings. 
It is not so effective against shrubs as is evidenced by 
the heath formations. 
9. Burning of soil causes reversions of plant so- 
cieties in the depressions; on others it leads to estab- 
lishment of forests, This is especially true if the 
