"Natural abundance" refers to the plentiful presence or occurrence of something in nature without any human intervention or manipulation. It means that something is found abundantly or widely in its natural state. Full definition
Found in natural abundance in foods such as whole wheat and soybeans, thiamine plays a key role in optimal body functioning. (phenocal.com)
REF envisions the Earth in balance — its original vitality and natural abundance available to all, for generations to come. (globaleducationmagazine.com)
In particular, he uses geochemical techniques for measuring natural abundance radiocarbon in ecosystem pools and fluxes to trace the sources of carbon emissions to the atmosphere. (searcharcticscience.org)