IMPACT OF THE NEW-ZEALAND FLATWORM (ARTIOPOSTHIA-TRIANGULATA) ON SOIL-STRUCTURE AND HYDROLOGY IN THE UK

Through north west Europe, concern has been growing in recent years ab out the predatory nature of Artioposthia triangulata on indigenous ear thworm species. In this study, the consequence of earthworm depletion by A. triangulata on soil structure and related hydrological processes is examined. Field measurements compare differences in saturated hydr aulic conductivity between sites overrun by A. triangulata and neighbo uring unaffected sites. Laboratory experiments were conducted on soil cores containing worms only, worms and A. triangulata, and a control w ith no worms or A. triangulata. Differences in the water release chara cteristic and bulk density between treatments was studied. It is concl uded that in the short term, infestation by flatworms and consequent d epletion of earthworms will increase infiltration. However, as macropo res degenerate or are removed over time, an increased risk of surface run off may result in increased pollution and flood hazards, whilst re duced drainage and subsequent waterlogging may reduce agricultural pro ductivity in certain soils. More research into understanding the proce sses is required. (C) 1998 Elsevier Science B.V.