That can't work. The bugs, fungus, bacterias invade an area and stay here for a long (unknown) time. After the devastation, their number drops down because the food availability is drastically reduced, but they are still there. That tends usually to an equilibrium. For example the big elms became a rarity, but we can still find small elms in the woods, hedges, garden... If you plant again the same trees, even a long time after, they will be soon attacked /destroyed by the survivals of the predators.
You have mainly three options to replace the dead trees.
- plant an other species, hopefully not harmed by the bug /disease. You get back the forest/landscape but it's different.
- introduce a strong predator/competitor of the bug /disease, then the new trees have more chances to survive.
- modify the species by selection, crossing, mutation.... It's no longer the exactly same tree, but it can live again in the deadly area.