Soil is the basis for the biodiversity of all land-based life on this planet. It is a part of a process that begins when bare rocks are colonized by certain species that scientists refer to as “pioneer species” (for example, lichens and mosses). As the lichens and mosses die off, they decay and are replaced by succeeding generations of lichens and mosses. This decay builds up as well, and over time, turns into the first layer of hummus in the creation of soil. As these hummus layers build up, herbaceous vegetation comes along, then shrubs, and then finally forest takes over. . It is a process that can take hundreds, or even thousands of years. This is how soil becomes a basis for an entire ecosystem,- including plant, animal, and microbial diversity.
Recent increases in the human population have placed a great strain on the world’s soil systems. With a population now of over 7 billion people, scientists today estimate that half of the Earths topsoil has already been lost. Much of this loss is the result of human activity relating to agricultural, industrial and urban purposes. Mismanagement by farmers, and overgrazing by livestock are seen as the major causes of soil degradation. Mismanaged agricultural practices can deplete the soil, and cause a loss of organic material, as well as a decline in soil fertility, in salinity, acidity or alkalinity. A final outcome is often erosion. In urban areas, the creation of roads and concrete with impermeable surfaces also contributes to erosion, streaming, and ground loss.
With over 7 billion people in the world today, the impact of the loss of soil and the effects on soil degradation are far reaching. With the loss of soil, also comes a great loss in biological diversity. This loss includes the microbial communities, it includes the disappearance of different stages and types of vegetation, and it includes a decrease in animal habitat. All of this together painting a picture of the loss in biodiversity and ultimately animal extinction. Modern day environmental scientists, in order to study and prevent further losses, often classify soil degradation into four major types: water erosion, wind erosion, chemical deterioration and physical deterioration.
The dirt beneath our feet is getting poorer and on many farms worldwide, there is less and less of it. Without sufficient soil, our ability to grow food is threatened. (From BBC).
Soil is the earth’s fragile skin that anchors all life on Earth. It is comprised of countless species that create a dynamic and complex ecosystem and is among the most precious resources to humans. (WWF)
Generating three centimeters of top soil takes 1,000 years, and if current rates of degradation continue all of the world’s top soil could be gone within 60 years, a senior UN official said. (Article from Scientific American).
While water erosion continues to be the most serious cause of soil degradation globally, innovative strategies that remediate important soil functions can restore the productivity of eroded soils. (Nature.com)
Soil degradation is the decline in soil condition caused by its improper use or poor management, usually for agricultural, industrial or urban purposes.