Overgrazing is a major environmental problem where groups of animals feed excessively from one area of land without letting the vegetation in that area fully recover. It is a phenomenon that can be seen both in the nature but also on livestock farms. It commonly happens when a farmer or an owner of the livestock keeps too many animals in one secluded area .
Unfortunately, overgrazing comes with many negative effects for native species, including soil erosion, land degradation and loss of valuable species.
Changes caused by overgrazing
The first and the most troublesome effect of overgrazing is soil erosion. If an area is allowed to be overgrazed, the vegetation is repeatedly being trampled and the native plants will be unable to grow and start dying.
Additionally, after the ground has been walked on repeatedly by large livestock, it becomes more firm and compacted, making it harder for the native vegetation to grow. Once the soil is free of vegetation, it is very easy for natural erosive processes such as wind or water to remove the top layer of soil .
Land degradation is a process that happens when no protective measures to address soil erosion are taken. The top layer of soil contains the highest amount of nutrients and when this layer and the nutrients are removed, it is very difficult to recover the soil quality.
Loss of the topsoil also makes it very difficult or nearly impossible for native plants to start to grow again. If land degradation process continues, it eventually leads to desertification .
The dust bowl of the 1930s in the United States was an example of the negative effects overgrazing, soil erosion and land degradation have on a landscape.
Loss of valuable species
Overgrazing also affects how native species are distributed in the environment and how they are able to regenerate. For example, after a pasture is overgrazed, the root system of native plants is damaged which makes regrowth difficult and slow. It often leads to the spread of non-native or invasive species . Then, it is even more difficult for the native species to recover.
The loss of native plants can also lead to a loss of native animal species, if an area that is overgrazed is part of an important habitat for a native animals.
An example of the damaging effects of overgrazing by wild species can be seen in the Caledonian Forest in Scotland. This area has seen a limited regrowth of young trees in the forest over the past 150-200 years due to overgrazing by native herbivores like red deer and sheep.
When the seedlings start to grow, they are eaten by these herbivores before they have a chance to grow. The problem has intensified due to the increasing deer population and lack of natural predators in the area to control the deer population .
Overall, there are many negative effects of overgrazing for native species. While some of the ways to prevent overgrazing include proper animal management, better land management, and sustainable pasture practices , they are often not performed. Even though these are important steps to take to preserve the quality of the land for future generations.