ECOLOGY OP ISLE ROY ALE. 235 



to open, sunny places. Lai'ge, charred trunks 34 feet in diameter are 

 still fairly abundant along the Greenstone and other ridges. Very 

 few young trees of this species were noted; and there are no indica- 

 tions, at present, to suggest that it will again become abundant on the 

 island. I, 3; II, 3; III, '04; VII, '04. 



163. Piivus resinosa Ait. Eed, or Norway Pine. Not abundant; 

 noted in two localities only. Occurs on high, exposed ground. Ill, 4. 



164. Pimis divaricata (Ait.) Sudw. Labrador, or Gray Pine. Fairly 

 common on exposed, dry rock ridges, and on a few of the rock islands. 

 Several in heath-forest tension zone near Kock Harbor light-house 

 Able to withstand highly xerophytic conditions. 



165. Larix laricina (DuEoi) Koch. Tamarack, or American Larch. 

 Principally in recently filled bogs or working in along margins of 

 partly filled ones. The tamaracks and Black Spruces are the pioneer 

 trees of the bogs. In the older bogs the few large tamaracks present 

 are relicts, and few young ones appear to be coming on. Scattered in- 

 dividuals occur throughout the upland forests but are nowhere abund- 

 ant outside the bogs. Largest individuals noted (V, 8) were over 3 

 feet in diameter, L 4; I, 6; II, 2; II, 4; II, 5; III, 5; IV, 4; IV, 8; 

 V, 5; V, 7; V, 8; V, 11; V, '04. 



16^. AMes halsamea (L) Mill. Balsam Fir. The most character- 

 istic and abundant evergreen of the upland forest. Abundant on all 

 parts of the island except the Greenstone Ridge, and in the more re- 

 cently filled bogs. Along the forest road from Washington, Club to 

 Lake Desor the absence of the larger firs was probably due to the 

 shallowness of soil, exposure to the powerful winter gales (as soon 

 as they overtop the maples and other trees among which they start to 

 grow), and the reduced root system in proportion to the size of the 

 tree. It reproduces readily in dense shade as well as more open 

 places, and is not only succeeding itself but other forest trees, as the 

 White Spruce. It will certainly occupy a large and important place 

 in the climatic forest. Up to 2 feet in diameter. I, 3; I, 4; III, 4; IV, 

 4; lY, 8; IV, 9; V, 4; V, 7; III, '04. . - - i • 



167. Picea camadensis (Mill.) B. S. P. White Spruce. ■Older trees 

 are fairly common where they have come in with AMes as pioneers. 

 It does not appear to be succeeding itself except along the edge of 

 clearings and in, more open parts of the forest. Since the Fir seedlings 

 are common under the older trees instead of those from the present 

 spruces it appears that the White Spruce will be replaced by the Fir 

 in the climatic forest, the Fir seedlings being able to endure much 

 deeper shade. I, 2; I, 3; III, 1. 



168. Picea mwriana- (Mill.) B. S. P. (Possibly Picea trevifoUa 

 Peck). Black Spruce. Confined principally to sphagnum bogs where 

 it comes in with the tamarack as a pioneer. The largest trees noted 

 were 314 feet in diameter. Also sparingly distributed outside of bogs. 

 In a few instances it was found growing on tlie exposed tops of cliffs 

 (as at Rock Harbor) where there is only a thin covering of soil. I, 6. 



169. Thuija occidcntalis L. White Cedar or Arbor-vitae. Occurs in 

 all bog areas except those most recently carpeted ovr. It does not 

 a])pear to come in as a pioneer hu( foHoAvs closely Picea mariana and 

 Lariw laricina. Largest specimens in old bog areas, V, 8, were 40 inches 



