Overgrazing occurs when livestock or wildlife overexploit vegetation cover in a given area. This can happen if the pasture is not given enough time to recover after each grazing season. Overgrazing can also occur when grazers are allowed to graze on pasture for an extended period.
CAUSES OF OVERGRAZING
When livestock are left to graze on a given piece of land for too long, it can lead to overgrazing. Below are some of the common causes of overgrazing. (Information from World Atlas)
Overstocking occurs when livestock are kept in a grazing land that cannot support their grazing capacity.
When there are too many grazers in one area, they tend to graze excessively to the detriment of the vegetation cover.
Repeated grazing limits pasture regrowth. With time, the land will be left bare, thereby causing other serious environmental problems.
Overstocking often results in intensive grazing, this will, in turn, cause overgrazing.
Improper Land Use
Certain human activities can contribute to overgrazing. For example, land clearing techniques such as slash and burn can deplete vegetation cover.
Mining activities not only pollute the environment but also degrades the soil. Areas where mining is taking place often have minimal or no vegetation cover.
Logging activities can also damage vegetation cover, leaving animals with nothing to eat.
Drought can be defined as prolonged water shortage in an area. When there is no water, pasture cannot recover in good time.
During periods of drought, livestock and wildlife overgraze on the available pasture due to food scarcity.
Overgrazing animals on a single patch of land will lead to the degradation of vegetation cover.
Drought can also cause the extinction of certain plant species in an ecosystem. This can leave the grazing land with unpalatable grass
ADVANTAGES AND DISADVANTAGES OF OVERGRAZING
Overgrazing is not in any way advantageous to the environment or the pasture recovery process. Nonetheless, it can help in the management of the wildlife population by encouraging migration. (Information from Population Education)
In the wild, herbivores tend to move from one place to another when searching for food.
Overgrazed lands are often left to recover as the animals move to other areas. The Great Wildebeest Migration in the East African region is a good example of animal migration.
Additionally, overgrazing can be a safe way of clearing land.
-Mongolia’s vast grasslands are slowly turning into deserts due to overgrazing. The Cashmere goats in this region have been foraging on the grass for decades. They damage root systems and prevent grass regrowth.
-The nomadic communities in Mongolia practice unsustainable grazing, leading to the gradual loss of vegetation cover.
-The Caledonian forest is found in Scotland. This area had a rich vegetation cover that has since been reduced by overgrazing and other human activities.
DISADVANTAGES/EFFECTS OF OVERGRAZING
Overgrazing is not good for the environment and the soil. It can lead to the degradation of habitats and the loss of plant species. (Facts from Encyclopdia.com)
Overgrazing Can Cause Soil Erosion
Overgrazing is one of the main drivers of soil erosion in most parts of the world.
Vegetation cover plays an essential role in preventing soil erosion. Grasses and other forage safeguard the soil against wind and splash erosion.
When livestock overexploits the vegetation cover, the soil is left bare. This leaves the land exposed to destructive elements.
Soil that s left bare can easily be eroded during heavy rains. Surface runoffs can carry the topsoil into waterways, causing pollution.
Land degradation can be defined as the reduction in the productivity levels of a piece of land. It is mainly caused by poor agricultural practices and overexploitation of land.
Overgrazing can lower land quality over time. Continuous grazing allows animals to trample the soil repeatedly, leading to compaction.
Compacted soil has poor infiltration and may prevent water from reaching the lower layers. As such, the soil will have a low moisture content, thus inhibiting plant growth.
Intensive grazing can also lead to the loss of fertile topsoil. Pasture cannot regrow if the soil has low fertility.
Loss of Plant Species
Overgrazing can lead to the loss of valuable plant species in an ecosystem. It also affects the distribution of native species and increases the spread of invasive species.
Allowing livestock or wildlife to graze in the same piece of land over and over damages root systems. Plants need their roots for the absorption of nutrients and water from the soil.
Damaged root systems can longer function as required, thus causing death to the affected plants.
The loss of primary plant species creates room for unpalatable forage in the grazing land.
Desertification is the process by which land gradually becomes a desert.
Since overgrazing depletes vegetation cover, the soil will lose its moisture-retaining abilities.
Overgrazed lands are directly exposed to the sun’s heat, so they lose moisture at a faster rate.
Desertification is harmful to the environment and also hinders biodiversity in habitats.
HOW TO PREVENT OVERGRAZING
Prevention of overgrazing is essential for the survival of both plant and animal species. Lands that are not overgrazed have more palatable forage. This allows livestock and wildlife to thrive. Overgrazing can be prevented through:
Proper Grazing Management
With proper management, grazing lands won’t be overexploited. Grazing management can take many forms depending on the method that is used.
Most livestock keepers employ rotational grazing in the management of grazing fields. This method involves the division of large grazing land into smaller portions called paddocks.
The animals are allowed to graze in each paddock for a limited duration. After this, they are moved to the next paddock. This allows the pasture to recover in the previously grazed paddock.
When it comes to grazing management, it’s all about the time that the animals take in a section of land. If the grazers spend too much time in one paddock, it may lead to overgrazing. Coming to a paddock that has not fully recovered can also damage the pasture.
Use Livestock Feeds
By providing livestock with feeds, the pasture will have enough time to recover. Livestock feeds can come in handy when there is minimal rainfall.
Livestock keepers with stockpiles of fodder can comfortably feed their animals as they wait for the pasture to regrow.
Farmers should keep the right number of animals to prevent overgrazing. The available land should support the grazing habits of the livestock at all times.
If the number of livestock increases, farm managers should expand the grazing fields.
OVERGRAZING IS DESTRUCTIVE TO THE ENVIRONMENT
Overgrazing is one of the serious problems that need to be dealt with. It destroys animal habitats, ecosystems, and the environment as a whole. Lands that have been overgrazed are highly susceptible to corrosion because they are left exposed.
Valuable plant species have also been lost due to overgrazing. Also, highly palatable forage has been replaced with unpalatable plants. This impacts the health of livestock and wildlife.