SOILGUARD had implemented a comprehensive strategy, engaging more than 500 stakeholders across the years in Europe, Argentina, Cameroon, and Thailand. Surveys, workshops, field reports, meetings, co-development sessions, webinars, and customised communications have reached a wide range of actors, from farmers and advisors to researchers, policymakers, and civil society representatives.
Research has established land degradation gradients for 7 EU NUTS-2 regions and three international regions, which are publicly available on the SOILGUARD website. Sampling protocols for soil biodiversity and soil multifunctionality were harmonized with Soil BON, LUCAS, and GSP. A total of 233 samples were analyzed, including taxonomic richness, abundance, and existing connections of faunal and microbial taxa and comparing their diversity at larger scales with the effect of location, soil attributes, climate, land use, or landscape features. This full soil biodiversity assessment collected a comprehensive list of measurements ranging from viruses to invertebrates’ diversity and abundance used for soil food web structure and co-occurrence patterns establishment.
SOILGUARD biodiversity status results show the importance of climate and region-specific soil features to determine soil biodiversity. Furthermore, the effect of soil management (conventional vs organic, low vs high species grasslands, and clear-cut vs continuous cover forests) and land degradation on soil biodiversity is highly region and organism-specific. Taking our results collectively, these suggest that shifting from conventional to organic farming would be more beneficial for fungi than for prokaryotes or soil invertebrates, under arid conditions (e.g. Spain, Hungary) and in already degraded soils (in comparison to those with low degradation levels). SOILGUARD also evaluated optimal landscapes to maximize crop yield, soil biodiversity and functioning, establishing where to foster EU’s farm to fork strategy transformation and showing a lack of intrinsic trade-offs.
In SOILGUARD we have used our comprehensive soil biodiversity database to contribute soil biodiversity indicators to the EU´s soil monitoring law. The objective is to give indicators that reflect changes in soil biota, their response to environmental conditions, and their functional consequences. Our results suggest that the monitoring of four indicators (fungal abundance, prokaryotic richness, the abundance of mites and microbial storage biomass) could represent about 70% of the variation in soil biodiversity changes, they are good indicators for environmental changes and management, as well as show strong relationships with the different soil functions measured. Cross-validation analyses suggest that these indicators could be generalizable to farmland regions other than the ones sampled, as well as to other biomes.
SOILGUARD has been studying the effects of field-simulated climate stressors and soil management on soil biodiversity and multifunctionality at 7 sites across Europe through two field drought simulations (2022 and 2023) and a heatwave simulation. The soil samples from the two years were analysed for multifunctionality metrics related to ecosystem functioning. Overall, the effect of climate stressors and interactions with soil management were notably modulated by local factors, and more visible on specific biotic groups or soil compartments. Thus, an impact is expected on future decision making at the farm and government scale, raising concerns about the long-term effects of these climate disturbances on soil biodiversity and functionality. Findings also highlight that short-term climate stress had a generally small and context-dependent impact, indicating substantial buffering capacity of soil; however, showing increasing effects on biodiversity associated with crops and more pronounced impact on eukaryotes, raising concerns about crop performance and specific soil functions.
An integrated valuation approach was developed to estimate the plural values provided by soil-mediated contributions to people and to quantify the benefits of sustainable soil management or – vice versa – the costs of policy inaction. This approach includes economic and socio-cultural valuation.
