The American people had and largely still have a natural environment which is unsurpassed in both scale and variety. But only within the last decade or so have they begun to view it as anything other than an inexhaustible storehouse of material wealth-of minerals, timbers, and furs.
The irreducible requisite of any successful planning is that the forms developed will direct the flow of energy in the most economic and productive pattern.
All organisms seek the natural environment most favorable to the complete development of their species, and where nature fails to meet the biologic necessities, adaptation of either environment or organism must occur for life to continue.