Influence of agriculture on Enchytraeidae fauna of soils in the south-west of the North Island of New Zealand

The enchytraeid fauna has been measured on 6 pasture soils (4 hill pasture, 2 dairy), 2 mixed cropping soils, 2 Kiwifruit orchard soils, and one native forest soil. Enchytraeid numbers were highest in the Kiwifruit orchards and the hill pastures and lowest on the dairy pasture and the native forest. There was no correlation of enchytraeid numbers with pH. All the agriculturally modified soils had a Fridericia-Lumbricetum oligochaete fauna, whereas the native forest soil had megascolecid earthworms and enchytraeids of the Mesenchytraeus-Cernosvitoviella type. The enchytraeid fauna is sensitive to changes in management, both in terms of total population numbers and species composition. However, the difficulties of measurement and identification limit their usefulness as routine bioindicators for sustainable management.