Although most mammal species are found within a range of habitats in London, the remaining populations of brown hare are virtually confined to arable areas on the fringes of the Capital.

There are few plant species with specific associations with agricultural land which still occur in London, largely due to the use of herbicides. However, some of these species (such as poppy Papaver rhoeas) are making a welcome comeback as a result of Countryside Stewardship and set-aside schemes. Rarities such as Deptford pink Dianthus armeria may survive as viable seed in the seed-bank in the margins of arable land on the chalk. It is perhaps interesting to note that many plant species formerly regarded as weeds of arable land are now more often encountered on wasteland sites across the Capital.

Much of the nature conservation value of ‘active’ farmland has become concentrated in the field margins, headlands and along field boundaries, particularly hedgerows. These remaining semi-natural habitats often support populations of common grassland butterflies such as gatekeeper and a host of other invertebrates which are an important food source for farmland birds, particularly during the breeding season.