I'm usually momentarily stumped* when someone asks me "Why do we need bushland?"
Um....let me see...
1. We breathe in oxygen and breathe out carbon dioxide, and by some strange quirk of nature, green plants take in carbon dioxide and give off oxygen. Coincidence? Or, perhaps, co-evolution of symbiotic lifeforms over millennia? (The carbon oxygen cycle is taught in schools, but maybe we need to remind some adults on a daily basis.)
2. Our suburbs are sterile heat islands designed predominantly on grid patterns based on squares and rectangles, and built to tender. Nature reserves are biodiverse refuges with endless variety of forms, colours and shapes, which have come into existence without employing human monetary concepts. Bushland and nature reserves, along with gardens and sympathetic landscaping, help "soften" the hard edge of our built environments.
Psychologists are only just starting to explore how much we rely on nature for our mental health (check out this 104-page literature review by Deakin University). Often the best thing we can do for our sanity is leave our artificial environment for a few minutes, walk into our "mother environment" and look at a leaf, a flower, a bird singing in a tree.
[Excuse me while I go outside for a few minutes before finishing this post!]
3. Bushland ecosystems are incredibly complex structures that provide undervalued "ecosystem services" such as native bees to pollinate our food crops, trees that transpire water vapour to become rain, and birds that do a better job at pest control than any insecticide (without the chemical side-effects). Not to mention all the nutrient recycling!
Ecosystem services are undervalued because most people take them for granted. Yet they are priceless. No-one has calculated the cost of designing technology to replace even one ecosystem service. We might be able to survive for a very short time without ecosystem services, but we can't live without them.
*Stumped, because the question I ask is "How could we possibly survive without bushland?"
("What have the Romans ever done for us?")