Associations of Enchytraeidae (Oligochaeta) in Experimentally Fertilized Grasslands

Abstract

(1) The enchytraeids in forty grassland fertilizer plots of different ages were identified. (2) Two plots were extremely acid owing to the continuous application of ammonium sulphate and only a few Marionina clavata survived this treatment. Two other plots were anomolous. (3) Thirty-six plots were classified on the basis of the proportionate abundance of species by indicator species analysis and four groups were obtained. These were a small group of acid plots with Cognettia sphagnetorum dominant or unique, a group of plots established on peat with species of Henlea and C. sphagnetorum dominant and two other groups with a diverse enchytraeid fauna. The first of these contained the controls and the slightly acid fertilizer plots where C. sphagnetorum, Cognettia glandulosa or Enchytronia parva were abundant or dominant and the second contained those plots which had received farmyard manure or neutral inorganic treatments where species of Fridericia or Enchytraeus were abundant and C. sphagnetorum was only poorly represented or absent. (4) Detrended correspondence analysis gave weighted mean species and plot scores for three axes and the latter were correlated with the treatments and some characteristics of the plots. Lime, pH, disturbance and yield were most significantly correlated with one or other of the first three axes.