The most vital aspect of soil is the number and range of organisms that live in it. Did you know that in a teaspoon of healthy soil there are more micro-organisms than there are people living in the whole world - a phenomenal statistic! Such organisms have an important role with respect to each other, their niche in the soil, the role they play in enabling the soil to perform its numerous important functions and its part in ecosystems. It is extremely important that in protecting soils we also recognise the need to protect the many organisms that live there. We should not do drastic things to the soil that might lead to the complete loss of some of the important organisms. Yet it becomes obvious that too little attention and respect is paid to this huge, hidden ecosystem.
There is much concern among soil scientists and even among some governments now that many of our world soils are becoming degraded because of lack of protection, lack of understanding and very often ignorance of the outcomes of some actions. There is evidence that many of the global threats to soils are also impacting on the soil's biodiversity and ecological capacity. Such threats, include soil erosion, decline in organic matter contents, salinisation, sealing by buildings and infrastructure, pollution and contamination. All of these can have a major impact on the organisms that live in the soil and the role they are able to play.
One of the major problems facing true assessment of the scale and importance of soil biodiversity is the fact that most of the ecological activity is below ground and out of sight, also many of the organisms are microscopic or sub-microscopic. There are so many different species that scientists still do not know the full extent of the diversity of these organisms; there are few accurate estimates of the numbers of species and more needs to be known about the role that the groups of creatures play in the many different ecosystems worldwide, for example, the tropical rain forests, the cold tundra region, prairie soils, and those soils in agricultural use. This lack of adequate knowledge makes it very difficult to estimate the full impacts of various types of land use and various forms of degradation on the soil biodiversity. Yet we do know that soil organisms are vital to the growth of plants, whether natural or semi-natural or under agriculture.