Enter the idea of 'rewilding'. The restoration of an ecosystem to it's former 'wild' state - complete with all trophic levels of flora and fauna - including apex predators (or more accurately 'tertiary consumers' in ecological speak). This large scale conservation movement
Here is a definition from Wikipedia:
Rewilding is large-scale conservation aimed at restoring and protecting natural processes and core wilderness areas, providing connectivity between such areas, and protecting or reintroducing apex predators and keystone species. Rewilding projects may require ecological restoration or wilderness engineering, particularly to restore connectivity between fragmented protected areas, and reintroduction of predators and keystone species where extirpated.The ultimate goal of rewilding efforts is to create ecosystems requiring passive management by limiting human control of ecosystems. Successful long term rewilding projects should be considered to have little to no human-based ecological management, as successful reintroduction of keystone species creates a self-regulatory and self-sustaining stable ecosystem, with near pre-human levels of biodiversity.
I find this concept really appealing. Too much of the world's biodiversity has been depleted and too little understanding of it's value to us as a species has been cultivated. If anyone has a love of the outdoors or the natural world, it's hard not to be inspired and a little enchanted by the idea of not only preserving the last remnants of the great 'wild' spaces of our planet but of expanding and restoring them to something approximating their former glory.
George Monbiot's TED talk below is a great introduction to this idea, and he explains some important concepts in how functioning ecosystems balance and regulate themselves. Have a look and see what you think.
In addition to everything George says, I also find it important to recognise that the restoration of ecosystems is not just about having wilderness out there for nature lovers, but also to restore the functionality of these systems - the benefits of which are numerous. Every important necessity we have as a human species is dependent on functional ecosystems somewhere - oxygen, rainfall not to mention our food - and all of which will become clearer in future as the climate changes and fossil fuels become more costly (across all metrics).
The advantages of having diverse, resilient and functional ecosystems are many, and the importance to our spirits may well be outweighed by the necessity for our long term survival and ability to thrive on the many benefits these 'wild' places give us.