Threats to soil integrity
The vast diversity and the important role of soil biodiversity in ecosystem functioning and ecosystem service delivery can be deeply affected by human activities as well as by natural disasters, though the latter may also be influenced by human-induced changes (for example, deforestation or road building causing landslides).
Most threats to soil biodiversity and function are directly related to human activities and associated with land use cover, management and change. These include deforestation, urbanization, agricultural intensification, loss of soil organic matter/carbon , soil compaction, surface sealing, soil acidification, nutrient imbalance, contamination, salinization, sodification, land degradation, fire, erosion and landslides.
STATE of KNOWLEDGE of SOIL BIODIVERSITY, FAO Report 2020
The major threats to soil biodiversity that are caused by human actions are, unfortunately on the increase according to sources such as CRED.
(CRED. 2020 EM-DAT the international disaster database. Université Catholique de Louvain, Belgium: Centre for Research on the Epidemiology of Disasters (CRED). See https://public.emdat.be/)
Notes on threats to soil and soil biodiversity
How threats interact, influence and re-inforce each other
Important interactions among several of the individual threats listed above and the combination of factors may combine to affect soil biota and its functioning.
A few examples
- plants under drought stress may be more vulnerable to invasive pathogens and pests.
- drought makes many soils more vulnerable to erosion.
- deforestation and floods heighten the likelihood of landslides.
- lowered rates of carbon sequestration in soils can add to climate change effects and more frequent destructive storms.
- floods transport contaminants to new soil locations
Extended example of interaction between stressors- permafrost 
Permafrost is ground that remains frozen for two or more years, and it lies beneath a vast portion of the Earth’s surface: in fact, 15% of land in the Northern Hemisphere contains permafrost. But the warming of the Arctic and other climate change impacts are thawing vast stretches of permafrost, creating a feedback loop that is accelerating global warming....
There’s a huge amount of carbon stored in permafrost — an estimated 1,500 gigatons, or twice as much as the atmosphere contains. This carbon is the remnant of plants and other organic matter that didn’t fully decompose in the frozen soils over thousands of years. (The oldest known permafrost is around 700,000 years old!) As permafrost thaws, bacteria can break down that organic matter, releasing that carbon into the atmosphere as the greenhouse gases - carbon dioxide or methane. Once in the atmosphere, these greenhouse gases further warm the planet, creating a positive feedback loop that thaws more permafrost. (https://climate.mit.edu/explainers/permafrost)
Over time, soil subjected to combinations of these threats can become unable to sustain an aboveground system and will become so greatly degraded, it is said to have become desertified..
Unfortunately, the level of knowledge of the impacts of these threats to soil biodiversity and function are highly variable, depending on the threat and the region, as well as the target biota (macro-, meso- or microfauna). e.g. here is a FAO assessment of the different levels of knowledge about threats to soil in Sub-Saharan Africa and in North America
What next?
Threats Summary 
Statement from the article The role of soils in the regulation of hazards and extreme events in the by the Philosophical Transactions of the Royal Society B
Nearly one-third of the world's soils are degraded, mainly owing to intensive cultivation practices that include the use of industrial pesticides/fertilizers and mechanized agriculture. Land use changes associated with cropland practices are significantly accelerating soil erosion, and are predicted to continue throughout the next century, with the greatest negative impacts primarily on the least developed economies. The modification of soil physical, biological and chemical properties through land use change can result in degradation, leading not only to soil erosion, but also to soil contamination, reduced soil nutrients and reduced infiltration. Soil degradation also exacerbates the risks associated with the hazards mentioned in the previous sections owing to loss of soil organic matter and storage capacity, and increased erosion potential.
There is increasing interest in soil science research occurring as we realise just how important healthy soil is to
- the production of healthy food
- the regulation of green house gases in the atmosphere
- the availability and movement of nutrients
- the filtering of water
- the production of novel molecules that may be beneficial
- the maintenance of biodiversity
The following article is a good summary of where soil science is at and where it is going - definitely recommended reading.
Soil Science Challenges in a New Era: A Transdisciplinary Overview of Relevant Topics