They build upon Ian McHarg's landmark use of maps in his efforts to make "ecological designs," that is, designs that do not damage or that rehabilitate degraded biophysical conditions of the landscape. His empirical method attempted to value the nonhuman conditions and interractions between organisms and their environments by rendering bisible those aspects of the landscape that are often unseen, unnoticed, or not valued. Mapping for McHarg meant mapping the elements of biophysical systems: soil types, vegetation communities, compatibilities between biological aspects and human needs, and the like. His method and its application not only changed landscape architectural design but also the subjects and methods of the use of maps in landscape architectural design.