Studies on the epigeal microarthropod fauna of grassland swards managed for silage production.
Abstract
The Acari, Collembola, Thysanoptera and Hemiptera (Aphididae) of various sward types were compared in a replicated field experiment at Grange, Co.Meath. The sward types were old grassland, and leys of Trifolium pratense, Lolium perenne and mixed Trifolium and Lolium. 126 species in all were recorded of which 82 were Acari. Trifolium plots had fewest species in 1974-5 and the old grassland plots had most, but by 1976 plot differences had largely disappeared due to an increase in numbers of acarine species. Mean arthropod density per plot ranged from 13 to 24 per g herbage. On average, Trifolium plots had smallest populations but rankings varied very much throughout the study. Populations were markedly larger in 1976. Analysis of dominance, similarity, principal coordinates, and patterns in distribution of relative abundance failed to establish any real differences between the communities of the various sward types. No relationships could be established between floral diversity, faunal diversity, and faunal stability. It was considered that any influence of sward composition on the fauna was being overriden by frequent cutting.