Being essential for the permanence of living beings in the environment we live, natural vegetation forms one of the important subjects of physical geography. Among the impacts of the environment over its natural elements, researching the vegetation thoroughly in all respects, through which direct source is obtained in most of the economic functions, has got a special importance, as well for our world’s future. In the examination of the elements of the natural and humane environment, which form the issues of geography, observation has a distinct place. One of the most important contributions of A.Von Humbold, a German geographer acknowledged as one of the founders of modern geography, is the observation method. In the research of the vegetation as well, which is one of the issues of the physical geography, applying the observation method is a must. In the research based on the in situ observations, identifying the vegetation either horizontally or vertically or in time will only be possible through an observation period applied according to its sort. Thus the distribution and distinctions of plant species and communities around the world can be found out onsite and revealed in a way connected with the factors that cause the distinction. Being mainly the climate; soil, topographic conditions and biotic factors directly affect the plant species and communities. In plant geography researches, in finding out the relations between plants and growing conditions, making observations in the field, forming correlation between statistical data and field’s natural elements are certainly essential in physical geography studies.