ONE WEN POMEOE ST oer 3 SR a ae Oe ee Re TE gee TE — 
1913] COOPER—ISLE ROYALE 223 
they are buried is unharmed, and are the most important con- 
tributors to the forest which immediately begins its development. 
Pyrus americana is similar to the birch in this respect, but is much 
less abundant. The shrubs of the climax forest seldom survive, 
though occasionally in a moist hollow a clump of Taxus will persist. 
The plants of the forest undergrowth, being close to the damp 
ground, frequently live through the fire. Some of them quickly 
succumb to the hard conditions which ensue, but certain species 
seem to thrive better than ever after the destruction of the forest 
cover. Prominent among the latter class are Cornus canadensis, 
Linnaea borealis var. americana, and Maianthemum canadense. 
These, which usually grow rather sparsely in the shade of the 
climax trees, come to cover large areas, flowering and fruiting 
luxuriantly. The first is one of the most characteristic species in 
the undergrowth of the burn forest. 
Upon areas where the forest has been destroyed but the humus 
little harmed the progress of the burn succession is commonly as 
follows. During the first growing season after the fire those relicts 
which have survived renew their growth, and many new arrivals 
appear. Certain of the latter are much the most prominent 
features for a number of years. These are the familiar fireweeds, 
Epilobium angustifolium L. and Anaphalis margaritacea (L.) B 
& H. (fig. 51). 
Biiouck the fireweeds give tone to the landscape for the first 
few years, the trees of the future forest begin their development 
equally early. The birches of the original stand, whose subter- 
ranean parts are still alive, sprout luxuriantly from the stump (figs. 
52, 53). Often a ring of a dozen or more shoots appears where a 
single birch of the previous generation stood. Many of these die, 
but some develop into trees. Seedling birches and aspens (Populus 
tremuloides) add to the number, but upon Isle Royale the birch 
sprouts greatly predominate. The result is the development of a 
forest composed mainly of even-aged birches in clumps of 2-6 or 
more (fig. 54). A rich shrubby vegetation accompanies the trees. 
Rubus idaeus var. aculeatissimus is usually the first. Diervilla 
Lonicera Mill, Corylus rostrata Ait., and Rubus parviflorus Nutt. 
follow. When the birches have attained a size sufficient to produce 
