Walk across an arable field of British wheat in summer. Count the species. You will find: wheat. Possibly a few resistant weeds the herbicide didn't catch. A handful of crows. Some pigeons surveying for damage. Roughly nothing else. Walk across a properly managed permanent pasture in the same county. You will find: 30 to 60 plant species in a good sward. Wildflowers. Clover. Vetches. Plantain. Ryegrass and timothy. Foraging bumblebees. Skylarks nesting in the longer patches. Hares in the margins. Beetles, dung beetles in particular, doing the work of two ecosystems at once. Field voles, kestrels overhead waiting for them. Swallows hoovering up insects above the cattle. The cattle are the reason the second field is biodiverse. Their grazing maintains the open structure. Their dung feeds the invertebrate web. Their hooves create the disturbance ground-nesting birds require. Remove the cattle, the pasture turns to scrub, and the species count crashes. The farm with the cows is the wildlife refuge. The farm with the wheat is the empty room. This is the inversion that nobody who writes for a Sunday supplement has worked out yet.