The Most Important Effects of Soil Erosion on Biodiversity
It has been estimated that at least half of all of the the topsoil in our world has been eroded within the last 150 years through human activities such as deforestation, overgrazing and unsustainable agricultural methods . Because healthy soil supports life on Earth, much of the life on our planet will be negatively impacted, including ourselves, if we continue to lose more topsoil. Throughout human history, heavy soil erosion has even destroyed entire civilizations .
In this article, we will discuss some of the most important effects of how soil erosion negatively impacts the biodiversity of our planet.
How does erosion affect biodiversity of our ecosystems?
Longer ecosystem recovery time
When soil erosion has occurred, it can take much longer for an ecosystem to recover than if the soil wasn’t so severely disturbed. Rebuilding healthy soil is estimated to take around 1,000 years to form one inch of soil when left up to nature’s processes alone .
If an ecosystem has been very degraded due to soil erosion, it will take a very long time for its biodiversity to recover, if it even recovers in that area at all.
Loss of topsoil and soil fertility, reduced native plant species
With a loss of topsoil, there is also a loss of soil fertility, as well as a loss of the optimal soil conditions for many native plants to grow.
When the soil has been very disturbed, weedy plant species often come in to colonize the disturbed soil. While this can be a good situation because the roots of the weedy plants can help to hold the soil in place and prevent further erosion, the weedy plant species can also consist of exotic invasive species that are able to colonize within the disturbed ecosystem. Such an “open door” opportunity for invasive species can eventually allow the invasive species to crowd out the native plant species that still exist in the ecosystem after the erosion disturbance.
In some cases, the eroded soil is so disturbed that the landscape becomes completely barren, and not much plant life will even grow there anymore. This barren landscape ultimately leads to a major decrease in ecosystem biodiversity for many organisms that can no longer live there.
Increased risk of flooding
Soil that has been heavily eroded does not tend to hold onto water very well. This can lead to an increased risk of flooding, which can in turn lead to even more erosion of remaining soil, negatively impacting the biodiversity of an ecosystem.
Negative impacts on aquatic ecosystems and species
Soil erosion can lead to the soil running off into waterways, which increases the sedimentation of the water, and makes aquatic ecosystems inhospitable for those organisms that require clearer waters for their habitat. Such negative impacts to aquatic ecosystems can also ultimately impact any species that prey on those aquatic species that are intolerant to turbid waters, potentially impacting the whole food chain of entire ecosystems.
In addition to the increased sedimentation of waterways, the pollution of water bodies can occur when the soil that is eroded is carrying any pollutants such as agriculture chemicals. These pollutants can negatively impact aquatic ecosystems, as well as any organisms that rely on aquatic organisms for food.
Increased risk of desertification
As soil is eroded, fewer plant species are able to live in the depleted soil that remains, and can ultimately lead to increase in desertification.
Solutions for reducing soil erosion throughout the world
Promoting sustainable agriculture and sustainable land use
By using sustainable land use methods such as no-till farming and permaculture farming, healthy soil is maintained and the chances of soil erosion occurring are significantly reduced, if not entirely eliminated.
Responsible and sustainable livestock management and grazing can also lead to a significant reduction in soil erosion from these activities.
By using sustainable forestry methods or reducing the overall rate of deforestation across the landscape, soil is much less likely to erode away because tree roots are very effective at holding soil in place.
Preventing desert expansion
Organizations such as the World Wildlife Fund are working to preserve and restore those ecosystems that are at risk of desertification, such as through the creation of a protected forest network that integrates conservation and sustainable development to support the economic welfare of local communities .