I wanted to continue my discussion on patches and edges that I began last week, by introducing the idea of human corridors. I found the diagrams that Prof. Sherman used from the Forman reading to be really helpful. Below are two I pulled from the reading.
The first is a diagram of what the ideal patch would look like. This is for two reasons, first the rounded core of the patch protects the species resources, and secondly because the “tentacles” of the patch allow species dispersal by presenting more opportunities for the patch to connect to other similar patches. This allows more opportunities for migration. The second diagram shows what Forman calls “stepping stone connectivity corridors” between two large patches, in comparison to a thick and stable corridor on the far right. The connections here are presented as linear paths but after being in this class we know that nothing is linear, this is just an idealized diagram and that these paths often occur looking much more like the tentacles from the first image.
Sally Elmiger, In the article “Corridors for a Healthier Environment” talks about these connections between both ecosystems and communities, and how they often interfere. Elmiger defines corridors as “Avenues along which wide-ranging animals can travel, plants can propagate, genetic interchange can occur, populations can move in response to environmental changes and natural disasters, and threatened species can be replenished from other areas.” She gives a very simple explanation of the danger in interfering with natural corridors and how we may be making a lot worse of an impact on natural systems than we think. For example, I liked the example she used about frogs; explaining that frogs need very specific conditions to reproduce which include not one but two habitats. Frogs need water for reproduction but spend most of their life on land. If some type of division (perhaps manmade) were to occur between these two patches the frog caught on either side would die off. Crossing the edge here is essential for the frogs existence.
Elmiger ends her article leading us into part two of “Corridors for a Healthier Environment” which she tells us will talk about what we can do in response to this knowledge. By raising awareness of the importance of these fragile connections we can help to build and develop to serve both humans and nature. Stay tuned for a response to part 2 of the article!
article url: http://www.for-wild.org/download/corr1.html