64 

 Lecture ir<, August 2, 1900. 

 Phygiographlf? Ideology of Long Island . 

 3 phases. 



1. Plants, organs, and their ecological relations. 



2. Plant societies and their ecological relat ions ( locally) . 



3. Climatic ecology or geographic botany. (Phytogeography) . 



Western prairies explained by climatic differences. 

 Edaphic as (local in character) opposed to climatic. Such factors 

 as have to do w-lth zonal distribution, springs, slopes, etc. 



Ecology used since 1895 vhen it was introduced by Warming. 

 Three distinct phases given above. Physiographic ecology deals with 

 relations of plants societies to their local environments. Two 

 distinct xmits in such a study. 



1. Topographic form, merely a stage in developgient of a region. 



2. Plant society an assemblage of plants in a common habitat. Also 

 a stage in the development of a region from the plant's standpoint. 



Physiographic Ecology has no histiry, since this may be termed 

 the prehistoric time. Begins really with Warming when he published 

 in 1895. Greatest work since then that of Schimper, in 1899. Other 

 papers have been published. 



T^daphlc Factors . 

 1. Water . Water level always modifies flora of a region, 

 ^hydrophytic soil 80/i. 



xerophytic soil 10 X 



raesophytic, between the two* 



