Habitat fragmentation definition: Causes: Examples:
It is currently estimated that 20% of animal species are in danger of extinction, with fish and amphibians being the most threatened classes of animals. The causes that lead to the extinction of species are multiple, but in short, the loss of habitats due to changes in land use contributes severely to the extinction of species. Meanwhile, habitat fragmentation processes collaborate in habitat loss and, as a consequence, not only animal species are affected, but also plant species.
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What is habitat fragmentation
Habitat fragmentation definition: Examples: We will start this post by developing what habitat fragmentation is all about. Habitat fragmentation is the degradation process in which a large and continuous area of a habitat is reduced and, as a result, is divided into two or more fragments . Habitat fragmentation undoubtedly leads to a loss of habitats for biodiversity, thus increasing its vulnerabilities and risk of extinction.
The effects of habitat fragmentation on biodiversity depend fundamentally on the shape of the fragment and the distances to other fragments. Meanwhile, those fragments that are isolated from other fragments and whose shape has a large border/area ratio, considerably increase the risk of extinction of the species since it alters their ecological processes, such as interaction with other specimens, search for food, mating, etc.
Habitat fragmentation definition: Examples: An example of habitat fragmentation occurs in the Chaqueno Forest in Argentina , in which the ecosystem is deeply fragmented as a result of changes in land use to carry out anthropic activities. Studies suggest that the fragmentation of the Chaco Forest has decreased the richness of native pollinating insects that precisely pollinate native plant species, while exotic bees have been favored by the effects of fragmentation.
Another example occurs in the Cantabrian Mountains in Spain, where habitats are fragmented by the construction of roads and the opening of forest tracks. The Cantabrian brown bear ( Ursus arctos arctos ) is particularly affected by this process of habitat loss as they require large areas to live.
Habitat fragmentation causes: The habitat fragmentation process is rather linked to the development of human activities . In the following list we will develop the causes that cause the fragmentation of habitats.
- Extension of the agricultural-livestock frontier: the intensification of agriculture and livestock causes a homogenization of the landscape, reducing the surface of natural habitats.
- Use of forest resources: the use of forest resources, mainly the use of wood resources, causes a fragmentation of habitats in forests, as well as deforestation to establish forest plantations of introduced species.
- Development of urbanization: with the increase in the world’s population, urbanizations are increasing in size, developing at the expense of the habitats of the species.
- Transport infrastructure: the construction of routes, roads and railway lines is one of the main causes of habitat fragmentation.
- Infrastructure in water courses: dams, weirs and reservoirs built on water courses represent a physical barrier for fish species, dividing their habitat into two or more parts.
Habitat fragmentation effects: As we have seen in the previous section, there are many causes that favor the fragmentation of habitats. Unfortunately, there are also many consequences that arise from this degradation process. Next we will develop each of them:
- In principle, the biological effects of habitat fragmentation threaten the existence of flora and fauna species, increasing their risk of extinction . This is because habitat fragmentation accelerates the reduction in the population size of species, leaving smaller populations vulnerable to genetic problems such as inbreeding. Likewise, a fragmented habitat alters the ecological processes of the species since it prevents the dispersion and migration of species, interactions between specimens, reproduction, alters food webs, among other implications. We recommend you read this other article on the Extinction of species: what it is, causes and consequences .
- On the other hand, it enhances the edge effect , that is, an increase in the proportion of the edge or perimeter of the fragment with respect to its area. The edge effect modifies the environment and causes microclimatic changes in light, temperature, wind, and humidity. These climatic changes constitute favorable conditions for fires, causing a greater incidence of them. In addition, microclimatic changes are sometimes favorable for the proliferation of exotic species. Here you can learn more about the Edge Effect: what it is and consequences .
How to avoid habitat fragmentation
Perhaps it is difficult to think individually how we can avoid the fragmentation of habitats. However, here we will give you some tips that will be useful.
- Stay informed about the problem. With all the knowledge acquired , demand from the politicians in charge of your area, the cessation of deforestation, the conservation of species and ecosystems and, mainly, the development of more protected areas.
- Get involved in ecosystem restoration projects and species conservation, either as a volunteer or donations.