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(Right) Wildlife movement around a
corridor - in this illustration birds fly along the interior of the
corridor, deer munch on plants found on the corridor edge, and a bear
meanders across the corridor. (Left) The illustration on the left shows
more than one type of corridor. This image illustrates a portion of a network of forest
corridors. It also shows a network of a human transportation corridors, or roads.
Often times natural corridors are more curvy, while human-built
corridors are composed of rigid geometries. These corridors cross each
other on the right side of the illustration - below, I touch on how
that crossing can work well and how it cannot work well. |
“Highways, new plantations, the fencing-off of certain
areas, the damming of water sources, and similar developments, crowd out
natural habitats and, at times, break them up in such a way that animal
populations can no longer migrate or roam freely. As a result, some species
face extinction. Alternatives exist which at least lessen the impact of these
projects, like the creation of biological corridors, but few countries demonstrate
such concern and foresight."
-Pope Francis I, Laudato Si', par. 35
The biological corridor Pope Francis is discussing is simply
a linear strip of habitat that differs from the land on either side of it. An animal's habitat is an area with the necessary conditions to support its survival. My habitat is where I live, and it can
be described by what and who enters and leaves that space regularly and
provides something necessary for me to function in that space. I have a daily
range of motion that is included in that habitat, and, on occasion, I go beyond
that daily range. However, there are places on this earth I simply cannot, nature
willing, go to and thrive—like the bottom of the Mariana Trench or the inside of Mt.
St. Helens. I tend to avoid those places. Animals in the
wild are much the same - they live in areas defined by the habitat requirements
of their species, and each species has a certain set of requirements for an
area to be considered suitable habitat. Some species are more sensitive than
others and they can rarely exist outside their habitat without pressing mortal
danger, like some arboreal bird species. Some species are "multihabitat," and
they are fine meandering through the landscape, whether in a field or a forest.
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Wildlife corridor movement |
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Land bridge in NJ, USA. wikipedia.org, user: Doug Kerr |
Corridors serve three primary functions. They provide a
conduit for organisms and other non-living things (such as soil particles), they
provide habitat for creatures and other life forms that live within them and along their edges, and
they create a barrier or filter for anything in an area that is moving towards the corridor at an oblique or perpendicular angle, like the bear to the right. A corridor of high-quality habitat that is
contiguous is ideal for the connection, dispersal, and migration of species populations, and
it is vital for those species that are not "multihabitat." The continuity of
corridors is often broken up by “Highways, new plantations, the fencing-off of
certain areas, the damming of water sources…” to quote the Pope. In the United
States, every day, 1,000,000 vertebrates traversing across the landscape are
hit by cars (Forman). This incredibly large number is indicative of a serious problem
of habitat fragmentation. Vulnerable animal populations attempting to obtain
resources missing from their current habitat, to migrate, or to reach other populations of
the same species in a fragmented landscape are more likely to meet a fatal end. It is not realistic to
propose getting rid of all roads and vehicular transportation, but design
solutions, such as wildlife underpasses and bridges, can make a significant
difference in the survival of these creatures.
Church lands could be assessed for their spatial
relationship to various corridors using mapping analysis. Where there is a lack
of continuity, perhaps the land could serve as an auxiliary patch. This is why a major focus of the Good Land
Project is to create a map of church properties, which will reveal ways that
the land could do much more for the environment - and it may also reveal where
land is already playing a critical role in the landscape and may be, at the least, helps increase the connectivity of a vital
corridor by providing a habitat patch. Existing Church lands could be serving
as crucial pieces of corridors and should be carefully approached with regard
to land-use planning if they are. However, without a comprehensive map of the
Church’s properties, we cannot know if this is the case.
Molly Burhans
goodlandproject.org
Sources:
[1] Pope Francis I. “Laudato Si’ - Encyclical Letter, On Care for Our Common Home, Pope Franci I.” Vatican: the Holy See. Vatican Website. Libreria Editrice Vaticana, 2015. Web. July. 2015.
This whole post is heavily influenced by:
[2] Forman, Richard T. T. Land Mosaics. Cambridge, UK: Cambridge University Press, 1995. Print.