Cut-Over Pine Lands in the South. 25 



to form humus, in which the soils of practically all that region are 

 deficient. On clay lands continually burned over, the soil is often 

 devoid of humus to such an extent that pastures will " clieckcrack " 

 in very dry weather and present much the appearance of the checks 

 in a dried mud puddle. The quantity of organic matter in a single 

 season's growth on cut-over land is very great, and when it is con- 

 sidered that practically all of it is consumed by fires the total loss 

 of valuable fertilizer can readily be appreciated. On land used for 

 farming purposes this annual destruction of organic matter means 

 a heavy loss in crop production and the additional use of commercial 

 fertilizer, which in itself is a poor substitute for a supply of humus. 



Another effect of frequent fires on native pasture has been to 

 keep out the desirable pasture grasses and perpetuate the unde- 

 sirable ones. Wire grass and broom sedge have been able to with- 

 stand fires to such an extent that they have almost taken possession 

 of the cut-over lands. These plants, although furnishing most of the 

 grazing, are undesirable because of their short grazing season, and 

 are no better adapted, except in their ability to withstand fire, than 

 carpet grass and lespedeza, the two most valuable pasture plants 

 found on the range. 



The reason for the ability of wire grass to withstand fire and not 

 close grazing is not altogether apparent, but it is largely accounted 

 for by the habit of growth and the season of growth. The grass is 

 perennial, firmly rooted, and grows in clumps, the stools of which 

 protect the growing parts from fire to some extent. The plant ma- 

 tures early in the season and the fuel for fires in the fall is largely 

 the dead stems and leaves of these plants. Thus it may be seen that 

 fall fires come at a time when the plant has seeded and the season's 

 growth is completed*, while the spring fires do not affect the stools of 

 the perennial plant as they do seedlings of annual plants and more 

 tender perennials. 



Although carpet grass is a perennial that stands close grazing, it 

 is very susceptible to fire. The seed is matured late in the fall, and 

 the plant is still growing at the time of fall fires. In the spring the 

 tender, creeping stalks are not protected to the same degree as are 

 the clumps of wire grass and broom sedge. 



Lespedeza is seriously checked by fires because it is an annual 

 which seeds late in fall at a time when fires are most likely to 

 occur. Unshattered seeds are all destroyed and most of the seeds 

 already dropped are destroyed, as they are loose and unprotected as 

 compared with later in the season after beating rains have covered 

 them with soil. The seeds are contained in a chaffy hull which burns 

 readily. Spring fires come at a time when the seeds are germinating, 

 or when the young plants are too tender to withstand fire. 

 141959°— 21— Bull. 827 4 



