northern and has actually crossed it in its southern section. West of the ridge in most of the regions where chestnut is wanting, its disappearance has been quite recent and, indeed, it is still disappearing.
This strange phenomenon is not confined to North Carolina, but is to be seen to a greater or less extent on the outer portions of the range of the chestnut, throughout the southern half of its range. Reports show that chestnut has largely died out or was formerly much more abundant in portions of Virginia, South Carolina, Georgia, Alabama, Mississippi and Tennessee, and that the recession is still going on.
This apparently mysterious decline in vigor of the chestnut in the south is evidently not due to any one factor, but probably to a variety of causes. Probably frequent forest fires are to blame for the beginning of most of the trouble, and these, as we have seen, are followed by the attacks of fungi and insects. The cutting over and clearing up of large areas may also result in soil conditions which are not as favorable as formerly. Climatic changes may also have something to do with the case.
If we summarize briefly the troubles of the chestnut described in the preceding pages, we find that in the northern half of its range it is a prey to the bark disease; throughout its whole area it is attacked by the two-lined chestnut borer, as well as by other insects, and also by fungi which destroy the heartwood. The common practise of coppicing can only be regarded as harmful when carried on for several generations. Forest fires have been frequent, resulting in injuries of many sorts. In the southern states still other factors are evidently at work.
Let us now turn to the other side of the balance sheet, i. e., to the assets of the chestnut, those traits in its life and habits which are of advantage to it in the struggle for existence and the perpetuation of the species.
Of first importance is its rapid and vigorous growth. Among the numerous advantages to be derived from this is the power to close over any chance wounds with new tissue with greater ease than would be the case in a more slowly growing species. And we have already seen how wounds may open the door to disease and decay.
An inherent powder for rapid growth also enables the tree to develop roots quickly in times of need, and also, in competition with other species in the forest, to lift its crown above them in order to secure better light. Moreover, in this connection we should recall that the chestnut is fairly "tolerant," i. e., not easily killed out or injured by the shade of older, larger trees.
As regards its soil requirements, we find that, unlike such trees as the tulip or basswood, it is not at all fastidious. Its principal needs seem to be an adequate amount of moisture in the soil, for it appears to be quite sensitive to drought, and also a soil which is fairly deep and loose. As to the chemical nature of the soil it is not particular, except that it rarely grows in a limestone region. Neither need the soil be a fertile one, for chestnut trees grow and thrive on sterile soils, provided they be porous
