Where is habitat fragmentation happening and what are its effects?
The effects of habitat fragmentation are varied throughout the globe, yet they impact a wide range of natural habitats and species. Here are some examples:
Natural Parks are abundant in Italy with over 20 National Parks and about 140 regional parks covering 10% of the land surface. However, Cinque Terre, Abruzzo, Lazio and Molise National Parks are where the natural habitat fragmentation, due to transportation infrastructures, is much higher.
In the Brazilian Amazon, research has shown that fragmentation within Amazonia has led to changes in forest dynamics, structure, composition, and microclimate, making remaining spaces highly vulnerable to droughts and fires; not to mention intensive hunting within fragmentation further threatening wildlife populations.
Intertidal wetlands and mangrove forest habitats are also at risk. In Southeast Asia, a global hotspot of mangrove loss, research found conversion to aquaculture and rice plantations the biggest drivers of loss and fragmentation.
What are Wildlife Corridors?
Wildlife corridors are one strategy designed to help nature deal with fragmentation. With habitat range size a strong predictor of species’ vulnerability to extinction, wildlife corridors help to link areas of wilderness together, thus creating larger spaces overall (Beyer and Manica, 2020). They assist in retaining, restoring, and managing natural connections and interactions across landscapes, whilst providing vital spaces for plant species to reside in and animal species to move through, find food, or shelter within.
Wildlife corridors are also known as biological corridors, green corridors, or habitat corridors. We can think of them as belonging to two main categories:
Natural corridors
Naturally established corridors have been created by natural circ*mstances and may have specific geographical features such as mountains and dense forests. They might be entire expanses of land like plains or prairies; specific forest ecosystems such as tropical, temperate, and boreal forests; or even a flowing water habitat which includes a river and its banks, also known as a riparian ribbon.
Manmade corridors
Man-made corridors have been established by humans for supporting and maintaining biodiversity across many different environments. The most common man-made corridors are the over and underpasses that were invented to avoid animal and human collisions via roads, but they also include smaller versions such as hedgerows on the edge of rural farmland.
There are two specific types of wildlife corridors:
- Continuous corridors are large, unbroken strips of green corridor that lead to another habitat.
- Stepping stone corridors are small patches of habitat that are connected by smaller wildlife corridors.
The benefits of Wildlife Corridors in action
Species known to use wildlife corridors include deer, elk, moose, bears, mountain goats, lizards, tortoises, sheep, wolves, big cats, and elephants. From the smallest insects to the largest land mammals, the meekest prey to the most cunning of predators; wildlife corridors can help species find food, sanctuary, and safe passage to a new home. Here’s just a few examples of wildlife corridors in action:
The Bee Highway in Norway was constructed in 2014 by the urban guild of beekeepers: ByBi. The “pollinator passage” stretches from Holmenkollen in the north west, to Lake Nøkkelvann in the south east. This project initiated measures such as green roofs, flower-emblazoned cemeteries and strategically placed beehives to make it possible for the bees to find resting places and food almost anywhere in Oslo.
The American Flyways signify the 4 unique aviation routes of migratory birds across the whole of the United States: the Pacific, Central, Mississippi and Atlantic Flyways. Birdlife International is working to help the 350 migrant species that breed in North America and head south for winter by creating lasting conservation partnerships across national borders.
In Australia in 2017, the Rainforest Trust established a 173.5 acre called the Misty Mountain Nature Refuge. The corridor is vital for animals (such as the near threatened Lumholtz’s Tree Kangaroo) to move freely between two large expanses of World Heritage rainforest. The trust is currently installing 17,000 locally sourced plants over the next two years to widen the corridor.
