A. W. KOCHLER The intimate intercourse between two or more 2. vegetation maps are scientific tools for ana­ fields of knowledge often bears interesting and lyzing the environment and the relation­ valuable fruit. Vegetation maps are such fruit, ships between vegetation and the site on resulting from the union of botany and geogra­ which it occurs. This helps to explain the phy. The work of botanists can be comprehen­ distribution of plant communities on the sive only if it includes a consideration of plants basis of the physical and chemical features in space, i. e. in different types of landscapes. At of the landscape. On the other hand, plant this point, the work of geographers becomes communities allow conclusions on the natu­ important through their development of maps re of the environment; as tools to determine and to analyze distribu­ 3. vegetation maps are valuable standards of tions in space. Our highly developed knowledge reference for observing and measuring of vegetation is matched by the refinement of changes in the vegetation, their direction cartographic techniques, and maps can now be and their speed, i. e. the rate of change. This is important because the character ofvegeta­ made that will show the extent and geographical distribution of vegetation anywhere on the sur­ tion is dynamic and is increasingly affected face of our planet with a remarkable degree of by man; accuracy. 4.