234 BOTANICAL GAZETTE [MARCH 
MINOR -NOTICES i 
_Lodgepole burn forests.—The Forest Service has recently issued a bulletin” 
which should be of great interest to all ecologists. Dr. F. E. CLEMENTS, 
working as collaborator, has made a study of the forests of lodgepole pine in 
the vicinity of Long’s Peak, Colorado. He finds that the lodgepole forests 
in that region are invariably related to forest fires, since the tree reproduces 
abundantly only under the conditions initiated by such events. 
y a determination of the ages of the oldest plants, principally lodgepoles, 
which have come into the given locality since the fire, and by study of fire 
scars upon the trunks, he sets the date of the fire and determines the extent 
of country affected by it. In this way he has discovered the dates and deter- 
mined the extents of many fires of the past two centuries, with considerable 
accuracy in the case of the recent ones, with less accuracy in the case of the 
less recent. Eight fires were found to have affected the region during the 
nineteenth century, and the areas covered by several of them overlap. There 
were four fires during the eighteenth century and a probable one in 1676. The 
accuracy with which the dates may be determined is due to the fact that 
abundant reproduction of lodgepole occurs the first year after the fire, and 
the majority of the trees are therefore even-aged to the year. ; 
A study of the life history of the species follows, in which is found the 
explanation of the particular type of forest which the lodgepole pine produces. 
Immediate and abundant reproduction is favored by fire because (1) it —_ 
the opening of many cones at once without damaging the seed; (2) it brings 
about the temporary disappearance of rodents, which ordinarily consume 
immense quantities of seed; (3) abundant light is provided, a necessity for 
reproduction and growth in this species; (4) cover competition is destroye¢. — 
Finally, the future development and treatment of lodgepole forests are 
discussed. If fire is kept out, the lodgepole forest zone will be gradually 
narrowed and ultimately crowded out of existence by encroachment of Douglas 
fir from below and of Engelmann spruce and subalpine fir from above, 
owing to the much greater tolerance of shade which these species Possess. 
_ In order to produce a new crop of lodgepole, clear cutting of the forest will 
be necessary, followed by thorough burning. Mere cutting without fire does 
not produce the requisite conditions.—WitLtam S. COOPER. ~ 
NOTES FOR STUDENTS 
Alcoholic fermentation.—Important contributions to our knowledge of 
the fermentation of sugar have been made by HARpEN and Youne, and by 
Iwanorr, in their experiments on the action of phosphates in alcoholic fermen- 
tation. Although these investigators agree in the main, their views differ a5 ' 
the details of the reactions involved in the fermentation of sugar in the presence 
‘ Cements, F. E., The life history of lodgepole burn forests. U.S. Dept. Agti-» 
Forest Service Bulletin 79. pp. 56. pls. 6. fig. I. 1909. 
