VEGETATION TYPES. 
165, 
Second, fire returns quickly to the soil the potash and other 
minerals stored up in pine straw and other dead leaves, and thus 
allows the pine to do a large business on a small capital, so to speak. 
For the soil is not very rich in soluble minerals, and these when 
taken up by plants are concentrated chiefly in the leaves, which in 
the case of most high pine land plants are tough and decay slowly; 
so that if many years elapsed between fires most of the mineral plant 
food near the surface might be locked up in an accumulation of 
dead leaves, and the trees would be threatened with starvation. 
Finally, if fires should cease entirely, it is reasonably certain that 
the high pine land vegetation would be gradually replaced by that 
of the sandy hammocks described below. For although there is 
little or no original or geological difference in the soil of the two 
types, the hammock trees seem to require humus and are sensitive 
to fire, and consequently they cannot invade the pine land very fast 
as long as fires prevail. The long-leaf pine, on the other hand, can¬ 
not stand much shade and crowding, so that it could not compete suc¬ 
cessfully with the hammock trees on their own ground. At the 
edge of a hammock the leaves of the trees must be continually fall¬ 
ing a little way out in the pine land, thus giving the humus-loving 
trees a chance to slowly encroach on the pines. 
It is very interesting to observe on the vegetation map that the 
high pine land almost nowhere forms small patches or narrow, 
tongues bordered by water or by vegetation not much subject to 
fire. The explanation is probably that fire could not easily run into 
such places often enough to protect the pines from the encroach¬ 
ments of hardwoods.* 
The following list of high pine land plants is based on observa¬ 
tions made in the Ocala area on 20 different days, in the months of 
January, March, April, May and July. No doubt field work in the 
fall would quickly reveal several additional herbs; though some 
of the fall-blooming ones have stiff stems which stand up through 
the winter and spring (or until the next fire), and thus enable the 
plants to be recognized in winter. Shrubs and herbs are lumped 
together, as was done in the case of the flatwoods, for otherwise 
*For additional notes on the influence of fire on long-leaf pine forests see 
Geol. Surv. Ala. Monog. 8 125-27. June, 1913 ; Literary Digest 47 1208. Aug. 27, 
1913; American Forestry 19 1667 - 669 . Oct., 191,3; Forestry Quarterly 11:545-546. 
Dec., 1913; Pop. Sci. Monthly 85 1353-355. Oct., 1914; Fla. Geol. Surv. 6th Ann. 
Rep. 184-185, 362, 384. Dec., 1914. 
