Trait-based approach and vulnerability analysis in hypogean environment: proposals and links to field

The traditional tools used in ecotoxicological risk assessment are lacking ecological realism, because in the field the situation is extremely more complex than in the laboratory. The link to the field is a key issue for a more realistic risk assessment. In the last few years two important concepts have been highlighted and proposed as tools for risk assessment: the trait-based approach that is based on the hypothesis that sensitivity is a function of biological characteristics, and vulnerability analysis that combines susceptibility to exposure, sensitivity to a stressor and recovery potential. Though their relevance is recognized as key-issues in modern ecotoxicology, relatively few studies on vulnerability analysis and trait-based approaches applied to terrestrial risk assessment are available in the literature. In this study these tools have been applied in a field study on a soil microarthropod community subject to pesticide exposure. A vineyard field site in Northern Italy was chosen and all the data regarding the application of agrochemicals were collected. The community was monitored in a year-round sampling scheme, according to the insecticide application when needed, from June 2008 to June 2009, inside the vineyard and in two points outside (4 m and 10 m away from the last row). First the results of the field study were evaluated with traditional exposure and risk assessment methods. Then, some important traits of the soil community were proposed to describe the characteristics relevant for determining population vulnerability (susceptibility to exposure, sensitivity, recovery capability). Finally, an attempt to perform a vulnerability analysis of the community to pesticide risk has been made and the major critical points are discussed.