Does improving an ecosystem by creating suitable habitats helps or harms wildlife populations?

It depends on the kind of changes you are making. If, by planting more native trees in an area that is naturally forested, this is improving the habitat for many of the local animals and helping the ecosystem there become more of what it should be. More trees can mean more homes for animals and a natural environment to live in. Most often, I would say that creating suitable habitats is a very good way of ensuring the wildlife lives more naturally and therefore better. However, improving the ecosystem by creating habitats in some ways could imbalance the animal populations. If too many animals live there in the spring, during winter it is possible that there would be a food shortage from the rising population. Also, building habitats for predators when the prey populations are weak could mean that the area will become overhunted by the rising population of predators.
Overall, the benefits on wildlife populations by creating suitable habitats far outweigh the risks, especially in most areas in a time like today. As animals are being driven away from their homes by humans, they need all the help they can get.