The role of earthworms for assessment of sustainability and as bioindicators

Earthworms, which inhabit soils and litter layers in most landscapes, can offer an important tool to evaluate different environmental transformations and impacts. Agricultural landscapes, urban and industrialized habitats have some earthworms that represent interesting indicators to monitor different contaminations, to assess different farming practices and different landscape structures and transformations. Species number, abundance and biomass can give easily measurable elements. Ecological guilds can help in comparing different environments. Taxonomy is relatively well known, at least in temperate areas, when species identification is in general easily solved. CD-ROM based programs facilitate rapid identification of collected specimens. The substantial amount of research carried out on these invertebrates has made these soil organisms more promising for further improved and accurate work in assessing sustainability of different environments. In most cases earthworm biomass or abundance can offer a valuable tool to assess different environmental impacts such as tillage operations, soil pollution, different agricultural input, trampling, industrial plant pollution, etc. In rural environments different farming systems can be assessed using earthworm biomass and numbers. (C)1999 Elsevier Science B.V. All rights reserved.