On the plan there will be noted a strip specially shaded, surrounding
the entire plat (fig. 13, _a_), representing a strip of timber which
should surround the farmer's wood lot, and which he should keep as
dense as possible, especially favoring undergrowth. This part, if
practicable, should be kept reproduced as coppice or by the method of
selection, i. e., by taking out trees hero and there. When gaps are
made, they should be filled, if possible, by introducing shade-enduring
kinds, which, like the spruces and firs and beech, retain their
branches down to the foot for a long time. This mantle is intended to
protect the interior against the drying influence of winds, which are
bound to enter the small wood lot and deteriorate the soil. The smaller
the lot, the more necessary and desirable it is to maintain such a
protective cover or wind-break.
[Illustration: Fig. 14.--Appearance of regeneration by group method.]