Effects of land use and agricultural management along soil degradation gradients on soil fauna in European sites (SOILGUARD) – a comparison between morphological and molecular data

Soil biota can sustain a wide range of functions and as such are intrinsically connected to soil health, which is defined as the capacity of a soil to function within ecosystem and land-use boundaries. Land use, soil management and land degradation can affect soil biodiversity and ultimately soil health. Soil fauna is an integral part of soil biodiversity connected at various levels of the food web with other important soil organisms such as bacteria and fungi. Nematodes are ubiquitous organisms sensitive to disturbances, and can be divided into functional groups based on feeding preferences and life-history strategies. Mites and collembola are two groups of microarthropods that are sensitive to land use change and soil management. These different groups of organisms can be used as indicators of soil biodiversity and health and can be measured with both morphological and molecular methods. Molecular methods offer great advantages compared to morphological methods, such as increase throughput and decrease costs and expertise needed for analysis, however only few studies have compared the information coming from both analyses. The objective of this study is to compare results of nematodes and microarthopods characterization obtained from morphological and eDNA methods in the framework of the European project SOILGUARD. To achieve this, nematodes, acari and collembola community characteristics have been assessed in seven European NUTS regions with different land use (forest, grassland and arable land), management (clearcutting vs continuous cover, grass monoculture vs grass-clover mix, organic vs conventional agriculture), pedo-climatic (texture, climate) characteristics, and land degradation gradient (organic matter levels). Soi fauna communities have been analysed with traditional morphological characterisation after extraction from soil and molecular methods with direct eDNA extraction from soil. Fauna-based soil health indices based on their abundance were calculated with information coming from both assessment methods. Results show disagreement between the two methods. More details about the outcome of this comparison will be presented and discussed during the conference.