Robert Hartig was a man who lived a long time ago and he liked trees very much. He was a scientist who studied plants and how they grew, especially trees.
He wanted to know why some trees got sick and died while others stayed healthy. So, he did some experiments to figure it out. He looked at the leaves and the bark of the trees and tried to find out what was causing the problems.
One day, he discovered that tiny creatures, called fungi, were the cause of the sick trees. These fungi were like little mushrooms that grew inside the trees and made them weak.
After figuring out the problem, Robert Hartig came up with ways to protect the healthy trees from these fungi. He also found ways to treat the sick trees so they could get better.
Thanks to his work, we now know how to take care of trees and keep them healthy. Robert Hartig was a very smart man who really loved trees and wanted to help them stay strong and healthy.