SOURCES OF HAEM TO THE FOREST. 23 



Sourwood seeds abundantly every year, and seedlings are plentiful 

 wherever there is light enough. They are very easily injured by 

 fire, but sprout vigorously after burning. Cattle generally avoid 

 them. 



Mowitam Laurel occurs in dense thickets at the heads of the ravines 

 through -which the plateau streams enter the coves. It is scattered 

 about in patches elsewhere on the plateau, but nowhere is it more than 

 a shrub. Seed is borne every year, and young plants are common. 



Persimmon is scarce at Sewanee. The tree grows only in the best 

 soil in open places. The largest tree found measured 8 inches. Repro- 

 duction was found only in one spot, where there was no underbrush 

 and where no fires had run for several years. 



Sweetleaf at Sewanee is confined to the ravines at the heads of the 

 coves, where it grows as a shrub in the scant soil of the rock crevices. 

 Its further distribution in the forest is limited by cattle, which eagerly 

 browse its leaves. It bears seed eveiy year, but no reproduction was 

 observed. 



White Ash is scattered b} 7 single trees on the benches of Northerly 

 Slope, where it grows to a good height and makes a clean bole. It 

 bears a full crop of seed about once in five } T ears; but, while seed- 

 lings occur now and then, reproduction is not general. The tree is 

 easily injured by fire, after which decay enters the wood. Large trees 

 are usually doty at the butt, and the crowns of many are infested by 

 a defoliating insect. 



Fringetree grows in shaded places along the cove streams, but is sel- 

 dom more than a shrub. Fruit is abundant ever} T year, but the fact 

 that the flower is. gathered has doubtless limited the distribution of 

 the species. 



SOURCES OF HARM TO THE FOREST. 

 FIRE. 



The Sewanee forest suffers from many enemies. The overgrazing by 

 cattle, the ravages of insects, the decay induced bj r fungi, the uproot- 

 ing of trees by wind, and the injury done by careless lumbering, all 

 share in the deterioration of the forest. But of all the sources of 

 damage, fire is by far the most serious. 



The ill effects of fire are not limited to the destruction of old timber 

 and of reproduction. It consumes the humus; it makes dead timber 

 in which harmful insects breed; it burns awa} r the protective bark, 

 admitting fungi into the injured trees, and by lowering their vitality 

 renders them less able to fight against decay. (PL V, fig. 1.) 



FIEE IS WORST ON THE PLATEAU. 



Fire is most common in the southern and eastern parts of the forest, 

 which adjoin the farms and the railroad; it does great mischief on 

 the plateau and very little in the coves. The level plateau offers no 



