We may not always realize it at
first glance, but the natural world is always changing; little by little, and
over long periods of time, but it is changing nonetheless, and a lot of that is
completely natural. However, as people with growing needs, desires, and technological
advancements, we are changing the land around us faster than ever before and
some of the first places affected by these changes are streams.
My name is Maddy Feiste and I am
a freshman student at Clemson University participating in the creative inquiry
Landscape Ecology of the Appalachia. In this program, a handful of us
undergraduate students are working under graduate student Nathan Weaver to
study the effects of urban development on stream health. More
specifically, we’re looking at the populations of salamanders that live in
those streams. Salamanders are an important part of the ecosystem in that they
are the main predators of insect larvae that grow and mature in streams.
They’re very effective keep insect populations under control by reducing the
number of larvae that survive to adulthood. Salamanders are also important to
us because many species serve as indicators of water pollution. For example, a
healthy stream will show many different species of salamanders, while a
polluted stream may only show one species of a highly tolerant salamander, or
even no salamanders at all. By surveying salamanders in various streams, we can
develop a good understanding of the stream’s overall health and the effects that
nearby exurbanization may be having on the water quality.
Fortunately for us, the southern
Appalachian Mountains are a biodiversity hotspot for salamanders, making it the
perfect place for us to study these valuable organisms. The same mountains, however,
have been an increasingly popular tourist destination spot for people seeking
what they consider to be the ideal getaway that brings them closer to nature.
This idea of the peaceful mountain getaway may at first seem harmless or even
beneficial, but the development involved brings us right to the problem of
exurbanization. Exurbanization is a form of low-density development similar to
urban sprawl. In exurbanization, houses and businesses are built farther apart
in order to provide a more secluded feeling for the people living there, while
still providing the services and amenities that would be available to them in a
larger city. All of this widespread development can seriously endanger streams
in the region by filling them with sediment from construction, as well as
runoff from roads and fertilized landscaping. This semester we went on multiple
sampling trips locally in order to assess how this type of development affected
the streams in and around Clemson.
When gathering our data we began
by testing the water quality in the streams, measuring dissolved oxygen,
salinity, pH, temperature, and conductivity. We then moved on to survey the
stream morphology, noting what percent of streambed was rock, gravel, pebbles,
or sediment. This data became especially important to me as we developed our
own personal projects. My particular topic has come to be streambed morphology
and how salamander species abundance varies according to substrate differences
between streams. As we continued to sample this semester, two important
differences became clear in urban versus control streams, and that was that the
urban streams had a high percentage of sediment, while our control streams
located in the Clemson experimental forest almost always contained less
sediment and more rock and gravel. The control streams also exhibited higher
diversity of salamander species than the urban streams, as opposed to the urban
streams, where we only ever found the very hardy southern two-lined salamander.
Knowing this, I wanted to investigate more into why sediment bottom streams
harbor fewer salamanders than rocky-bottomed ones. It may be that the more
uniform sediment provides less habitat for salamanders and their prey than
layered pebbles and rocks would, but only more research will tell for sure.
I’m very excited to continue this
creative inquiry into next semester and gain a greater understanding of the
relationships that salamanders share with their physical environment.
Sedimentation is a well-known problem for streams and in many cases has been
known to completely fill in streams so that they no longer exist. Runoff and
storm water management are both environmental issues that I am passionate about
and that I would like to continue to investigate further with this project. I think
that next I would like to compare a stream near a town using conventional storm water
management practices to a stream from an area using more sustainable practices. It would be interesting to see if there are
very significant differences in the salamander diversity of the different
locations. I look forward to writing about more of my findings in the coming
spring!
No comments:
Post a Comment