Depends on the catastrophe in nature and the consideration of the civilized areas. What extant terrain of the area has been co-opted and converted to an urban environment, so it depends on the existing ecosystem in place. Generally you can consider the city itself as a parasite or disease that is growing over time, so the areas near it are already doomed.
Besides, one philosophy of nature is the natural balance, that barring intervention, nature WILL prevail. Bombing it all to ashes and letting life thrive from the ground up is feasible.
It also depends on the type of catastrophe.
Weather based disasters are a rich profit for nature, if a three month long hurricane pounds all habitation into shrapnel, you lose larger lifeforms and trees, but smaller creatures will emerge into a paradise.
Aquatic disasters are somewhat worsened versions of weather, you slam everything with water and drown/break it all, which kills a lot, but what is left over is rich material for growth, and provided its not lingering, most seeds are still viable.
Geological disasters are superficial as far as nature is concerned. it really only harms brittle, rigid materials significantly.
Volcanic is a bit more...thorough, and would require special measures to repopulate after the heat cooks it all to death.