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ECOLOGIC DISTRIBUTION AN INCENTIVE TO THE STUDY OF 



LICHENS. 



By Bruce Fink. 



Until quite recently the study of Lichens in America has been wholly 

 confined to taxonomic problems. With the reaction in other fields of botan- 

 ical activity it seemed for a time that the "golden age of lichenology" had 

 surely passed. In this transitional stage lichens have been neglected, but 

 with the change of front in botany has come the work of Dr. W. C. Sturgis 

 upon the reproductive processes, and quite a number of very illuminating 

 physiological and morphological papers by Dr. Albert Schneider, culminat- 

 ing in his Text-Book. Also the writer has made a beginning of the study 

 of ecologic distribution of Lichens. 



In the revival of interest in the study of lichens ecologic researches are 

 surely to be a dominant factor. It has not escaped notice that lichens are of 

 extreme interest ecologically. Yet the prerequisite knowledge of species is 

 not possessd by ecologists generally, and for this reason lichens have been 

 for the most part neglected in their studies. Moreover, I am well convinced 

 as a result of extended study in the field and in the laboratory that these 

 plants can scarcely receive adequate consideration from an ecologic point of 

 view in any general paper. Whether this is true of any other plants below 

 the spermaphytes I am not prepared to give an opinion, but there surely 

 must appear a number of workers who will seriously study lichens ecolog- 

 ically before the matter will receive proper attention. 



I have already hinted at a good knowledge of species as a prerequisite. 

 A systematic study of the lichens of a region may be accomplished in a rea- 

 sonably short time, and this, supplemented by keen powers of observation, 

 is absolutely necessary in field work. To these qualifications should be 

 added some acquaintance with structural geology and with the species of 

 trees bearing the lichens. The workers must also become familiar with the 

 late literature of the subject of ecology or phyto-geography. Armed thus 

 the close observer will find such a multiplicity of interesting questions aris- 

 ing in the field that he will frequently be compelled to avoid too great an 

 amount of detail. Local conditions as to light and moisture must be con- 

 stantly kept in mind, nor should the more strictly edaphic conditions be 

 lost to view, that is, the conditions of environment substratic, rather than 

 climatic. Fortunately lichen formations as a rule need not be studied at 

 different seasons of the year, nor need they generally be studied through a 

 ■ series of years for the purpose of noting the succession of species, as this 

 comes about so slowly that little will be gained by such investigation except 

 where the work may be continued for two or three decades. Again, lichens 

 are commonly more widely distributed than the spermaphytes, and general 

 climatic conditions need not, receive so great an amount of attention in 

 studying their distribution. The fact that one may continue his studies 

 through a whole season, always finding his plants in good condition, and 

 may confine his attention for most part to local conditions rather than wide- 

 spread climatic ones, simplifies the work quite materially. 



