


We 
FLOWERING PLANTS: | 
THEIR STRUCTURE AND HABITAT 
CHAPTER I 
INTRODUCTION TO PLANT ECOLOGY 
Scope of PLANT Ecology (Gk. oikos, a house, and logos, a dis- 
Ecology. course) is the science which treats of everything 
relating to the habitat of plants. It investigates the exact 
physical conditions under which the plants of a given area are 
living ; it notes the adaptation of their organs to these external 
conditions ; and, lastly, it determines what plants, through 
their power of response to similar conditions, grow together 
and are thus associated with each other. 
Physical § lhe physical features of a country or district 
Conditions. are of primary importance in this study, for it will 
be found that the plants which grow together, forming the vege- 
tation of the district in question, are those which either require 
the same conditions or can adapt themselves to them. From 
this point of view the most important physical features are : 
1. The amount of moisture and, connected with this, the 
porosity of the soil. 
2. The duration and intensity of light. 
3. The temperature, 
These, to a certain extent, depend on the latitude and 
altitude of the district. The latitude and altitude of a country 
or district help to determine its vegetation. ‘Thus the vegeta- 
tion of the tropics is, speaking broadly, different from that of 
1—2 
