Earthworm indicators as tools for soil monitoring, characterization and risk assessment. An example from the national Bioindicator programme (France)

Abstract

International audienceConsidering the limited number of bioindicators available to assess soil quality, a national research programme was set up in France to develop such indicators (2006-2012), the "Bioindicator" programme. This programme tested 47 biological parameters (i.e. microorganisms, fauna, flora) including earthworms, in several sites differing in terms of land use, contamination type - PAHs or metals - and pollution levels. The present study proposes some study objectives for bioindicator approaches, based on the earthworm results from the programme. Therefore, different earthworm descriptors were tested at the community level (e.g. abundance, biomass, species and functional structures, and ecological traits) as well as the organism level (i.e. measuring the metallothionein coding gene expression level in earthworms). The present results, obtained from the programme's spring 2009 sampling campaign, discriminated among the different descriptors and showed that earthworm and endogeic abundance as well as the individual weight of endogeics seem to be good indicators in non-contaminated (cultivated) sites, while the ecological structure, namely the proportion of anecic vs. endogeic species, and the proportion of non-vulnerable species should be used as indicators of contaminated soils. Furthermore, the first results obtained for Lumbricus terrestris and L. rubellus rubellus are encouraging as they show that metallothionein expression increases in metal-contaminated soils. The relevance of these descriptors, which have to be considered in study objectives, requires the analysis of 2010 results

Soil biodiversity, biological indicators and soil ecosystem services—an overview of European approaches

“…Such indicators, either biological, physical or chemical, should be able to give information about the state and trends as well as the seriousness of the situation, and are assumed to be of value to environmental management goals and decision making ( [3,8] [2]). The soil community provides a large number of potentially interesting bioindicators for environmental monitoring in response to a range of stresses or disturbances [17,[22][23][24][25]. However, the diversity of applications and types of bioindicators can cause some confusion regarding the type of information they provide.…”

“…[28][29][30][31][32][33]) or soil contamination (e.g. [23,25]). The parameters being measured comprise different soil organisms selected for their sensitivity to soil management or environmental conditions and/or their relevance for important ecological functions (e.g.…”

“…The parameters being measured comprise different soil organisms selected for their sensitivity to soil management or environmental conditions and/or their relevance for important ecological functions (e.g. organic matter decomposition, N mineralization or soil structure formation) [25]. Recently, there has been an increasing interest in developing bio-indicators as proxies for soil functions or ecosystem services, or soil quality or soil health in general (refs).…”

“…Frameworks for selecting bio-indicators for national-scale soil monitoring have been devised in, for example, France [25], the Netherlands [31,38] and the UK [36]. These frameworks had in common that a wide array of candidate indicators was assembled and tested for their suitability to be used in systematic measurement of soil biodiversity.…”

Evaluation of Earthworms Present on Natural and Agricultural-Livestock Soils of the Center Northern Litoral Santafesino, República Argentina

“…In the 2000-2009's pesticide market had triplicate [5] being the most popular endosulfan, lambda-cyhalothrin, cypermethrin, chlorpyrifos, metamidophos and the herbicides glyphosate, atrazine and 2,4D [6]. Importance of edaphic fauna to the soil fertility is well known, especially with oligochaeta that are being used as bioindicators of the soil health [7][8][9][10][11][12][13].…”