The influence of cultivations on soil animal populations

Abstract

Wild habitats such as woodlands and grassland usually support a diverse flora and fauna. Even these are used for agriculture, this flora is replaced, either by a few species of plants when grassland is reseeded or by a single species when an arable crop is sown; this, in turn, usually causes a decrease both in the total numbers and species diversity of the animals associated with the flora. Such changes have been thoroughly investigated for the insects that live on the aerial parts of plants, but there have been few experimental investigations of the effect of cultivation on populations of soil animals (Edwards and Lofty, 1969). Although it has been assumed that cultivation decreases numbers and diversity of soil animals, such assumptions have been based on relatively sparse data from surveys of the fauna of different habitats, and may be unjustified because most of them have been based on single population estimates and have taken no account of changes in populations with time.