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Do you remember that small patch of forest near your house that you use to play in as a child? I do. I remember it as a lush, vibrant play area full of flora and fauna. The squirrels, the birds, the occasional coyote made it seem so diverse. It seems that my childhood memories are, sadly, twisted because recent research shows that small fragmented habitats are not diverse at all and cannot sustain even small mammals for just twenty five years!
In 1986 a large area of the Chiew Larn Reservoir in Thailand was flooded, leaving many little islands, and as cool as that sounds it is not a good thing. After choosing sixteen of the many (like more than one hundred!) islands researchers surveyed the populations five to seven years after the flood took place. They found that on larger islands only seven to twelve native species of small mammals were sustained by the habitat. The results were even worse on the smaller islands. Only one to three species could survive on the tiny pockets of vegetation amidst the water.
Somehow the situation gets even worse! By the end of twenty five years almost all species are extinct on all sixteen islands! And just like when a character in a movie says, “well at least it’s not raining” and then it starts to rain, this situation get even worse because of “rain”. In this case the rain is rats. While the native species were going extinct their places were being taken by rats. I for one can’t imagine anything worse than that! The study also suggests that the rats could have helped accelerate the rate of extinction on the forest fragments. So now we all have one more point to add to the list of reasons about why we hate rats.
And in case you are wondering, “hey how do we know that it’s the fragmentation causing the extinction”, the study covers that. As a control to their experiment the researchers also took surveys of mainland populations and did not find the same loss of biodiversity.
So, I think we can all agree as wonderful and pleasant as those small forest fragments may seem as children they can be very detrimental to biodiversity. Unfortunately it seems especially in cities that conservation efforts always take the form of creating stepping stone, which from this recent study we can tell aren’t always very effect ways to foster species growth. Because of this let’s resolve to take more active participation in conservation, whether that’s writing to your local representative or going to a rally!
Gibson, Luke, Antony J. Lynam, Corey JA Bradshaw, Fangliang He, David Bickford, David S. Woodruff, Sara Bumrungsri, and William F. Laurance. “Near-Complete Extinction of Native Small Mammal Fauna 25 Years After Forest Fragmentation.”Science 341.6153 (2013): 1508-510. Science. 27 Sept. 2013. Web. 28 Oct. 2013.