Nottinghamshire Wildlife Trust's Spalford Warren reserve covers 36 hectares of blown sand heath with conifer plantations and is a Site of Special Scientific Interest (SSSI).
The main habitat found on the reserve is sand-blown heath, which is one of the rarest habitats in the county with the nearest equivalent being in the Brecks of Suffolk and Norfolk. Much of the area is planted with Corsican and Scots pine and there is some oak regeneration. The poor soil is material deposited after the last Ice Age and gives rise to an unusual plant community for an inland site.
In the Second World War it was used as a munitions dump to supply the many local airfields and from 1965 onwards the Forestry Commission planted conifers. Some interesting plants have been lost due to rigorous forestry management, but fortunately interesting pockets have survived.
Species of interest include slender trefoil, field mouse-ear and shepherd's cress. Fauna includes solitary bees, sand wasps and common lizards whilst bird species recorded include sparrowhawk, green and great spotted woodpeckers, woodcock, coal tit and redpoll. Common blue and small heath are the most frequently seen butterflies.
The reserve (Grid Ref. SK 827678) lies to the east of the A1133 Newark-Gainsborough road almost midway between the minor roads to Girton and Spalford. The reserve is open to the public at all times, but visitors must keep to the tracks and footpaths.