Regard and protect ground-nesting pollinators as part of soil biodiversity

While the Convention on Biological Diversity employs a habitat-oriented definition of soil biodiversity including all species living in soil, the Food and Agriculture Organisation, since 2002 assigned to safeguard soil biodiversity, excludes them by focusing on species directly providing four ecosystem services contributing to soil quality and functions: nutrient cycling; regulation of water flow and storage; soil structure maintenance and erosion control; and carbon storage and regulation of atmospheric composition. Many solitary wasps and 70% of wild bees nest below ground and require protection during this crucial period of their lifecycle. Recent research demonstrated the extent of threats to which ground-nesting pollinators are exposed e.g., chemicals, deep tillage and soil compaction by heavy machinery. Ground-nesting pollinators change soil texture directly by digging cavities and more importantly contribute indirectly to soil quality and functions: 87% of all flowering plants require pollinators and so do all ecosystem services provided by these plants. Without pollinators, soil would lose all ecosystem services provided by these flowering plants (https://www.youtube.com/watch?v=l3CFQ4KAgmI). Above- and below-ground biota are in constant interaction. Below-ground species are mobile to limited extent, loss of pollinators highly impacts soil diversity. Therefore, the key-stakeholder, the Food and Agriculture Organization should protect ground-nesting pollinators explicitly within soil-biodiversity conservation, particularly by (a) obligatory complex pesticide risk assessments with different ground-nesting pollinator species, (b) knowledge-raising campaigns concerning nesting particularly of ground-nesting pollinators (https://youtu.be/IB7KJ3phAO8) and promotion of at least one dedicated area without second tillage, heavy machinery and pesticides in each square kilometre of arable land.