The role of earthworms for assessment of sustainability and as bioindicators

Abstract

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, where 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.

Earthworm communities in organic and conventional coffee cultivation

“…In the region, for many years, BHC (1, 2, 3, 4, 5, 6-Hexachlorocyclohexane, now banned), and other pesticides toxic to earthworms -e.g. organochlorine insecticides, carbamates and copper-based fungicides (Paoletti, 1999;Edwards & Bohlen, 1992) -were regularly used in conventional coffee cultivation against pests and coffee rust (Abramovay, 1999). The potential long-term impact of these pesticides on earthworm populations under coffee is still unknown.…”

“…Therefore, intensifi cation of agricultural production, with the use of tillage, fertilization, irrigation and pesticides, can affect soil fauna populations both directly and indirectly, by altering the suitability of the soil environment. Practices normally associated with low addition of external, inorganic agricultural inputs foster the diversity and abundance of earthworms (El Titi & Ipach, 1989;Paoletti, 1999).…”

Comparação entre doses de Alil isotiocianato e a solução de formaldeído na extração de minhocas

“…A densidade populacional e biomassa de minhocas são influenciadas pelos fatores climáticos e propriedades intrínsecas do solo, cobertura vegetal, práticas agrícolas, intensidade de mecanização, manejo dos resíduos, utilização de fertilizantes químicos, defensivos agrícolas, adubação verde e orgânica entre outras (EDWARDS, 1983). Por essas razões as minhocas são consideradas excelente indicador do tipo de uso e da qualidade do solo (Paoletti, 1999).…”

Effects of the herbicides benfluralin, metribuzin and propyzamide on the survival and weight of earthworms (Octodrilus complanatus)

“…In particular, their feeding behavior might be affected by herbicides and this abnormality can be reflected in the weight loss and low reproductive capacity of earthworms (Zarea and Karimi 2012). For the ecotoxicity testing of herbicides on earthworms, parameters such as density, biomass and biodiversity of earthworms, are usually studied (Paoletti 1999). Weight loss is a valuable indicator of physiological stress on earthworms, related to the degree of intoxication and time of exposure of examined species (Yasmin and D 'Souza 2010).…”