A Study of Micro-Arthropod Communities in Mineral Soils Near Corby, Northants

Abstract

Many of the animals comprising the soil fauna appear to be very susceptible to small changes in micro-environment and undergo enormous fluctuations in numbers which suggests that competition for these resources must often be intense. The resulting community pattern observed must therefore be an integrated response to the environment in its broadest sense. Comparison of seasonal changes in community patterns in different soils allows one to detect those features which vary with time and thus to distinguish those that are indicative of fundamental differences in soil condition. The present work was done in an area where land is being reclaimed following open-cast quarrying for ironstone. Thus it was possible to select sites which represented various stages in the reclamation process and to examine the fauna to see whether any succession of species was apparent. After an initial survey, three sites were selected for intensive study on land owned by Messrs. Stewarts & Lloyds Minerals Ltd. and situated 2-3 miles NE of Corby, Northants. The first of these, Site 0, was on the southern edge of the Prior's Hall reclaimed land (National Grid Reference SP 934917). It occupied a small tongue of land of about I acre levelled in 1949 but not included within the field boundaries and thus not sown with grass and lucerne in 1955 like the rest of the area. It was dotted with coltsfoot (Tussilago farfara L.) and small grass tussocks but for much of the year was predominantly bare ground. The second, Site 1, was chosen from among fields of the Deene reclaimed land (Grid Ref. 913917). This field of about 6 acres had been sown to grass in 1948 and was thus one of the oldest experimentally reclaimed fields in the district. For comparison with these two, Site 100 (Grid Ref. 936926) was an area of more mature grassland; it had long been parkland and after arable cultivation from 1940 to 1946 had been returned to permanent pasture. While Site 100 had not been affected by quarrying operations, the other two areas shared a similar history of excavation by face shovels resulting in permanent loss of topsoil and mixing of the various geological strata lying above the ironstone beds. Left originally in series of parallel ridges called 'hill and dale' they were levelled by filling in the hollows and thus the final surface would consist of a mosaic of subsoil types from the Great and Inferior Oolite Series comprising sands, silts, heavy clays and sandy limestones.