The Dangers of Habitat Fragmentation

It’s no secret that deforestation and habitat loss pose a dire threat to the diversity and wellbeing of life on Earth. Wildlife populations worldwide declined by an average of 69% between 1970 and 2018, with much of the loss caused by habitat destruction.

However, the issue isn’t simply the amount of natural environment being destroyed, but also the way that destruction reshapes the physical boundaries of ecosystems in a process known as habitat fragmentation. Read on to learn more about what this worrisome phenomenon means for global biodiversity and what conservation advocates are doing to combat it.

Understanding Habitat Fragmentation

A consequence of forest destruction and loss, habitat fragmentation occurs when continuous areas of natural environment get broken up into smaller, isolated sections. This can happen due to natural causes such as wildfires and floods or it can be caused by human encroachment into our planet’s fragile ecosystems. Picture a highway dividing a forest in two, or sections of prairie being separated when land is razed for growing crops.

When native plant life is indiscriminately cleared for human activities such as agriculture or urbanization, the remaining patches can be left disconnected from one another. This makes it more difficult for various animal species to feed, breed, migrate, and survive, and poses a significant threat to regional and global biodiversity.

Impact on Wildlife Populations

One of the most immediate and direct ways that habitat fragmentation can harm wildlife is the process itself. The means by which environments are destroyed and separated, whether by bulldozer or natural disaster, can displace or kill the animals that call those environments home. But the danger doesn’t stop there.

Smaller habitats give wildlife less room to nest and feed. This means that animals may experience greater food scarcity and be forced to venture into more hostile environments to forage or hunt. They can also become more vulnerable to predators, as shown in this study on how North American mountain caribou grew increasingly endangered as their forest home became fragmented.

When forests are divided into isolated patches, more species are forced to live close to the forest’s edge. This area can be a more dangerous environment than the forest’s interior, with greater exposure to predators and human interference. It can also be hazardous to plant and animal species that have adapted to thrive in the interior’s microclimates. These “edge effect” issues are increasingly pervasive; as of 2015, 70% of the planet’s remaining forest was within 1 kilometer of the forest’s edge.

Habitat fragmentation also threatens biodiversity by eroding genetic variation within species. A smaller, isolated population decreases the number of potential mates, which lowers the species’ genetic diversity and makes these populations more susceptible to inbreeding. Genetic diversity is an important determinant of a species’ resilience, strengthening their ability to resist diseases and pests and adapt to environmental changes. This negative impact on genetic diversity has been measured in birds, mammals, and a variety of plant species.

Conservation Solutions

Science-based reforestation methods are crucial to combat the threat of fragmentation in our planet’s forests. One of these methods is to create wildlife corridors (also known as habitat corridors or forest corridors) to connect isolated habitats. These strips of regrown natural environment allow species to move freely between previously separated patches, which promotes genetic exchange and reduces other negative effects.

Creating a wildlife corridor can be a complicated and costly process. Conservation organizations first need to purchase the land between the fragments they wish to connect, which can be publicly or privately owned. Then they need to engage in thoughtful restoration and reforestation practices, making sure the wildlife corridors are repopulated with a variety of native vegetation in an efficient and sustainable manner.

Despite these challenges, many NGOs and governments across the world have managed to create successful wildlife corridors. They can range from large-scale reforestation projects to smaller wildlife crossings and bridges built into urban infrastructure.

Of course, the best way to combat habitat fragmentation is to prevent it from happening in the first place. By establishing protected nature reserves and raising community awareness about the dangers of deforestation and habitat loss, conservation advocates worldwide are working to preserve the precious ecosystems we still have left. But they can’t do it alone.

Conservation non-profits rely on donations of time, money, and resources from everyday people and organizations in order to keep doing their crucial work. This generosity can allow environmental NGOs to save and restore natural habitats, protect animal and plant populations, and turn the tide in the fight to preserve our planet.

ReWorld is currently raising funds for Proyecto Tití, a conservation non-profit working to protect tropical forests and endangered species in Colombia. Click here to learn how you can help them battle the effects of habitat loss and fragmentation by creating the world’s first community-funded tropical forest and biodiversity preserve.