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WHAT IS FOREST FRAGMENTATION?

Forest fragmentation occurs when a large forested area is broken into smaller patches scattered across a landscape. These patches are often divided by roads, utility lines, and other manmade structures.  Forest fragmentation is also known as habitat fragmentation, and it can have a detrimental impact on the environment.

WHY IS HABITAT FRAGMENTATION BAD?

Forest fragmentation can change how the environment functions. This can harm plant and animal communities in the following ways:

Loss of Habitat

  • Fragmentation reduces the amount of available space for organisms in an environment. This will create competition among species. It can also lead to extinction. 
  • When animals lose their habitat, they are likely to migrate to other areas.

Changes Forest Structure

  • Forests are made up of a series of trees and plants that are interdependent. When forestland is fragmented the edges are left exposed. This will increase temperature, light levels, and wind speeds.
  • These factors can lower humidity levels inside the forest. When humidity is low, plants lose water rapidly.

Divides Metapopulations into Subpopulations

  • Most terrestrial animals thrive when they are in large groups.
  • Habitat fragmentation divides animals of the same species into smaller groups. This can increase their extinction rate.

Disrupts Ecosystem Function

  • Forests fragmentation can lead to a dysfunctional ecosystem. Fully functional ecosystems provide plants and animals with everything that they need.
  • Ecosystems perform three main functions—cycling of nutrients, creating balance, and regulating essential ecological processes in an environment.

Creates a Barrier for Movement

  • Fragmentation can limit the movement of animals. As a result, species from a given habitat may crowd in one place. This will lead to the depletion of resources.
  • For example, highways that pass through forests and wildlife reserves can increase traffic mortality. The animals will be forced to cross the road when switching habitats.

Decline in Population Density

  • Forest fragmentation reduces vegetation cover in a habitat. This means the animals won’t have enough food to eat.
  • When food is scarce, all the animals in the food chain are affected. Long-term scarcity can cause animals to die.

CAUSES OF FOREST FRAGMENTATION

Forest fragmentation can result from human activities and natural processes. Fragmentation can occur rapidly or after an extended duration.

Human Activities That Cause Forest Fragmentation

Certain human activities can split vast forestlands into small fragments that are hard to manage.

Deforestation

  • Deforestation is the clearing of forest cover from a large area. When trees are purposeful cut from an area, the forest will be reduced to smaller plots.
  • A high rate of deforestation can lead to the destruction of forests and the extinction of plant species.

Construction of Hydroelectric Reservoirs

  • When constructing hydroelectric reservoirs, trees have to be cut. Reservoirs that are built inside or around forests can split the forestland into sections.
  • These reservoirs can also cause habitat fragmentation in aquatic ecosystems. This will impede the movement of fish and other aquatic animals.

Agriculture

  • Large portions of forests are converted into farmlands each year. Thousands of trees are cut, leaving only small fragments of forest cover for the animals.
  • Agricultural activities can greatly impact the ecosystem and the environment as a whole.

Rural Development

  • Trees found in tropical forests are cut to create room for new roads and settlements. The remaining trees form smaller patches of forestland that cannot sustain native animals.
  • As these areas continue to develop, the higher the rate of forest fragmentation.

Pollution

  • Air pollution can disrupt photosynthesis in trees. It damages foliage and prevents respiration. Trees growing in a highly polluted area are likely to wilt and die.
  • Pollutants can also cause stunted growth in certain sections of a forest. When trees are exposed to toxic elements for a long period, they become weak. This makes them susceptible to diseases.

Natural Processes That Cause Forest Fragmentation

Forest fragmentation can be caused by processes that occur naturally in an environment.

Volcanic Activities

  • Volcanic eruptions produce lava, poisonous gases, and ash. Forests that are located near volcanoes can experience fragmentation when there is a subsequent flow of lava.
  • Lava can burn vast sections of forests. The ash and the gases can affect both plants and animals.

Floods

  • Fast-moving floodwaters can cause mass destruction of trees in forested areas. Trees can easily be uprooted and washed away by flash floods.
  • Floods can cause root damage by carrying away the topsoil. Exposed tree roots are likely to freeze or dry out. Without roots, trees cannot absorb nutrients from the soil.

Fires

  • Naturally occurring forest fires can result from lightning strikes. Wildfires can cause severe damage to certain parts of the forest, leading to fragmentation.

FOREST FRAGMENTATION AND BIODIVERSITY 

Biodiversity is the variety of animal and plant life in an ecosystem, habitat, or environment. Forest fragmentation can directly impact biodiversity.

  • Splitting forestlands into smaller fragments can cause the extinction of endangered species.
  • Extinction not only occurs in animals but also in plants.
  • Forest fragmentation can prevent the dispersal of seeds in flowering plants. This will prevent certain plant species from growing as they should.
  • Forest fragments have few resources. Fragmentation can cause members of a species to have a hard time finding food and water.
  • Forest fragmentation reduces symbiotic interactions between animals in a habitat. It can also alter community composition by limiting mutualistic interactions between plants and animals.

HOW TO REDUCE FOREST FRAGMENTATION

Forest fragments can be linked using a range of restorative procedures:

Replanting Trees

  • Two or more patches of forestland can be restored by planting new trees in between them. The trees will grow and cover the spaces over time.

Creating Buffer Zones

  • Buffers can be created along forest edges to prevent the temperature from rising. This will allow trees to retain more water. 
  • Consequently, the trees will grow rapidly and will also spread their seeds to the adjacent patches. With time, the number of trees in the fragmented landscape will increase, thus closing the gap between patches.

FOREST FRAGMENTATION IS A THREAT TO THE ENVIRONMENT

Forest fragmentation can severely damage ecosystems, resulting in the loss of species. Forest fragments are hard to manage when it comes to conservation.

People need to take action and restore degraded forest lands before it is too late. The most effective way to go about this is by planting trees in the affected areas.

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