A rather large number of species of birds, invertebrates and plants as well as a few species of mammals are closely connected with such habitat structures, in most cases originally found in steppe or dry grassland habitats. Fields under regular cultivation hold just a fraction of the biodiversity generally found in farmland landscapes. With an increased fragmentation and reduction in size of natural and seminatural habitats in the farmland landscape, it has become increasingly difficult for farmland biodiversity to persist in the gradually smaller and fewer suitable habitats and to spread between habitats of sufficient quality to maintain viable populations.