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Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S-V and S-O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N-P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S-V, S-O and N-P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N-P, S-O), and pendimethalin (S-V). Total residue content in soil reached values of 0.8 mg kg-1 for S-V, 2 mg kg-1 for S-O and N-P, and 12 mg kg-1 for P-G. Organic soils presented 70-90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Soil remediation techniques should be developed to keep the levels of pesticide residues below such benchmarks. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures and their residence time in soil.

Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S–V and S–O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N–P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S–V, S–O and N–P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N–P, S–O), and pendimethalin (S–V). Total residue content in soil reached values of 0.8 mg kg−1 for S–V, 2 mg kg−1 for S–O and N–P, and 12 mg kg−1 for P-G. Organic soils presented 70–90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures at the conversion time and their residence time in soil.

Hydrologically isolated forest pools, both vernal and permanent, are receiving increased attention in conservation because they often provide fishless habitats for forest-dwelling amphibians, reducing risk of predation to eggs and larvae. However, clarifying conservation value of such pools requires determination of whether the species they contribute to local biodiversity are unique or also present in other nearby wetlands such as freshwater marshes. We compared composition of amphibian communities in clustered pools to that of both spatially isolated pools and freshwater marshes in Illinois (USA) from 2008 to 2010 to determine (1) effects of clustering on community structure, species richness, and occupancy dynamics; (2) unique contributions of forest pools (six clustered and three isolated pools) to amphibian diversity compared to marshes (n = 6); and (3) species-specific probabilities of occupancy by wetland type. Amphibian communities differed among wetland categories, with community similarity in the same year reduced 38% by differences between marshes, clustered pools, and isolated pools. Species richness was similar in clustered pools and marshes, but lower in isolated pools. Clustered pools contributed more species (n = 10) than marshes (n = 7) or isolated pools (n = 4). Anuran species had higher probability of greater relative abundance and salamanders had greater probability of encounter at clustered pools than at isolated pools, and probabilities of species-specific site occupancy were lowest at isolated pools. Wildlife managers in Midwest USA can better understand species-specific occupancy dynamics of amphibians in different wetland categories through this analysis and can optimize local amphibian species richness through conservation of clusters of forest pools.