I’M STANDING IN the shifting forest in the muted light of dusk. Above me, a tall tree with a vast tapering trunk stretches its antlered branches into the sky. Mountain ash, Eucalyptus regnans: the tallest flowering plant in the world. Fern fronds wave in the wind and bushes hunch in the understorey. I hear rustlings in the leaf litter. The monotonous rhythmic piping of an eastern yellow robin. The distant cackle of a kookaburra: the last bird to call before night. In the gloom I wait, listening to the breath of the forest, the hum of mosquitoes. It’s peaceful in this small patch of old-growth forest: a rich world of trees and creatures, interactions and interdependencies that combine to create a functioning ecosystem. Soon the cloak of night will fall and, if I’m lucky, an animal may emerge from a hollow high up in my tree.

I am here with a group of volunteers led by researchers from the Australian National University under the guidance of my partner, ecologist Professor David Lindenmayer, who’s been studying this forest since 1983. David and I met twenty-eight years ago over a Leadbeater’s possum at Sir Colin MacKenzie Sanctuary near the township of Healesville, where I was working as a veterinarian. As I stepped into the sanctuary vet hospital that morning, a dark-haired man with kind brown eyes smiled up at me. Not long after that, we began a relationship, and since then our lives have been enmeshed in the politics of native-forest logging, which are as complex and layered as the forest itself.