Studying native plants involves getting glimpses of how the landscape used to be.
Lewis & Clark kept mistaking what they thought looked like bodies of water in the distance, but turned out to be fields of blue camas in bloom.
A single oak tree can produce more than a ton of acorns. 1\3rd of the trees in forests in the eastern half of America were chestnuts, also highly productive. And then there's the tonnage of food that used to self-deliver upstream in the form of salmon, and how much beef could be harvested from the massive herds of bison, with not a fence or rancher in sight?
It takes a VERY BAD year, for people in an unspoiled landscape and the skills to understand it, to go hungry.
And it takes VERY BAD PEOPLE, for anyone in a modern world producing so much more than it needs, to go hungry.