What is habitat fragmentation? And what can we do about it?
By Pamela Sleightholm
We understand habitat loss, that human development has encroached on wild habitat, pushing animal species into smaller and smaller areas.
An equal problem that receives less attention is habitat fragmentation. All animals – mammals, insects, birds, fish, and amphibians – need lots of space to forage or hunt, rear their young and mate. As humans have moved into more wild spaces, not only are we reducing the total amount of habitat available, we’re dividing the wild space into smaller and smaller chunks. These smaller parcels of land don’t compare to the original tract – not just in size by area, but also in quality.
There are two main types of habitat – interior habitat and edge habitat. Interior habitat is sheltered, safer and removed from human activity. There is an abundance of plants and the creatures that depend on them. Interior habitat can support larger populations, greater biodiversity and provides more protected area for foraging, hunting and breeding. This habitat is essential for all kinds of wildlife.
Cutting a parcel of land in half - whether for a road, farm or condo - disproportionately increases the amount edge habitat, which is less protected with lower diversity
Edge habitat is just as it sounds – it's the areas around the outside of the forest. These areas are much more exposed with less diversity. Edge habitat experiences direct sun, wind, rain and snow. They’re harsh environments compared to interior habitat - and some species can not thrive in them at all.
Complicating the problem of reduced size is the increased distance between the habitat patches. Many animals and plants become stranded within these "islands". Most native solitary bees, for example, have a range of only about 300 meters. These isolated populations have limited gene pools, and their successive generations of offspring weaken due to inbreeding. They become susceptible to disease and stress and decline until they can no longer sustain themselves.
The solution? Re-connect fragmented green spaces with city-wide habitat corridors which can provide enough food and nesting services to enable wildlife mobility.
In Mississauga, we’re lucky to have several large, fairly undeveloped parks – but the spaces between them are vast, especially for little creatures like our native bees. Even neighbourhood parks are too far apart for bees. The goal of Blooming Boulevards is to connect these larger spaces – the interior habitats – by creating wild corridors throughout the urban landscape. To date, we have installed 136 pollinator gardens in every corner of the city to connect our wild spaces to the species that need them. In 2022 we hope to install 100 more gardens.
You can help our local wildlife by converting some of your lawn and garden space to habitat - including native plant pollinator gardens, native trees, vegetable gardens and fruit trees. There's so much to gain for humans from these plantings, and they'll help our local wildlife too!
Remember - Our 2022 garden applications are open now - why not take advantage of our offer of free plants, advice and support?
Wildlife Habitat Fragmentation - https://wildlife.org/wp-content/uploads/2014/05/Wildlife-Habitat-Fragmentation.pdf
Habitat Conservation and Wildlife Corridors - A Secondary School Lesson Plan - https://conservationcorridor.org/wp-content/uploads/Connectivity_lesson_plan_habitat_fragmentation.pdf