Wednesday, April 16, 2014

Stream food webs in an altered environment

The following is guest post by Briana Cairco, a freshman at Clemson University enrolled in Dr. Barrett's Creative Inquiry course focused on amphibian conservation.

My name is Briana Cairco, I’m a freshman wildlife and fisheries major and entomology minor at Clemson University in South Carolina. This semester I’ve have the wonderful opportunity to take a Creative Inquiry class studying the effects of exurbanization on salamanders in Appalachia. As you may or may not know, the Appalachian Mountains are home to more species of salamander than any other place on earth, so there is no better place to study salamanders than in our own backyard.

So, what is exurbanization? Exurbanization is basically urban sprawl, people like having the amenities of the city, but want to live in a more rural area. So, land outside of cities is developed to provide easy access to the city, and a more natural environment to live in. This process may be the best of both worlds for humans, but these exurban communities can decimate the ecosystem they’re in. These communities may not seem so bad at first glance, but when you consider the sedimentation from the construction, the runoff from fertilized lawns, the increased salinity from road salt, and so many other factors that impact the streams, the threat these communities pose to amphibians is very real. Our goal this semester is to sample streams with a varying exposure to these developments in order to determine the effects exurbanization has on the salamander population as a whole.

Within our group each person is conducting his or her own research on a related topic. I chose to research the relationships between species of macroinvertebrates and species of salamanders. I will be using the salamander data we get and collecting data on the variety of invertebrates and looking at any correlation between the two. Salamanders are the top predator in these streams that we are examining, so when their populations suffer it is safe to assume that the invertebrate community will change as well. Either they will increase because they aren't being hunted, or they will decrease because whatever is threatening the salamanders is threatening them too.

Certain species of both invertebrates and salamanders are more sensitive to environmental changes. When we look at the data between sites with different water quality readings it would be interesting to see if any of the species seem to be sensitive to particular variables. Between sites with similar water quality, results may show which invertebrate and salamander species have interdependent relationships. There are so many variables in these sites that it could be hard to say whether particular species have a special relationship, but it would be really interesting if for example, sites with caddis fly larvae as the predominant invertebrate also seemed to have the most black belly salamanders. Maybe this study could show if the salamanders have a favorite food, or it could just show which invertebrate and salamanders have similar habitat preferences.
The task is a little daunting since there are so many things out of our control, the invertebrate populations will be affected by the season, so I will have to take into account the breeding period for the species we find.  Also, the size of invertebrate is important a small stream could support thousands of tiny stonefly larvae, but obviously not as many hellgrammites. So instead of just comparing the numbers, I’ll need to compare changes in species abundance between sites.

I will be using this identification key from Auburn University to identify the invertebrates by order, then by their feeding group. There are four feeding groups; shredders, which rely on dead plant and animal material, scrapers/grazers, which eat living plant matter and algae, predators, which eat other invertebrates, and collectors/filterers, which filter fine material from the water.  Most stone fly larvae are shredders, except for families Perlidae, Chloroperlidae, and Perlodidae which are predatory, and have obvious physical differences. The mayfly larvae we will encounter will be collectors, except for family Heptageniidae which are scrapers, and are also easy to differentiate because they appear to have no head.  The caddis fly larvae are more difficult to differentiate so since the majority of species are scrapers, any caddis fly larvae will be classified as a scraper. The megalopterans (like hellgrammites) are predators; as are both dragonfly and damsel fly larvae. I think these feeding groups will be helpful in connecting stream quality and both salamander and invertebrate abundance.

I’m really excited to start sampling, and I haven’t seen any articles about the relationships between certain invertebrates and salamander species yet, so I have no idea what to expect.

Moving from the classroom to the field

The following is guest post by Will Gallman, a freshman at Clemson University enrolled in Dr. Barrett's Creative Inquiry course focused on amphibian conservation.

I am a freshman studying in the field of Wildlife and Fisheries Biology. The Landscape Ecology of Appalachia creative inquiry (CI) interested me because it seemed related to some of science fair projects I completed in high school, and because I was ready to start learning applicable field techniques. The research we are doing as a whole is designed to see how the long term effect of ex-urban development in the mountains is affecting salamander populations in first order streams. Each student also has an individual research project that we are to complete alongside the main research. My individual project, will be determining whether elevation influences the relative abundance of salamanders.

So far for most of this course, because of cold weather, we have been reading and discussing existing research papers. I have benefited greatly from this, because I have learned research methods along with a plethora of things about salamanders and other amphibians. These papers also have helped us narrow the topics for personal research. The research topic I chose didn’t directly relate to any of the papers, but the papers offered ideas on the types of research that can be done.  

I originally had a couple of different ideas for research but narrowed it down to studying how elevation influences the abundance of salamanders. During a summer ecology experience, I went on a trip where we learned about and caught terrestrial salamanders. I learned, based on the elevation, certain species of salamanders are more commonly found. From this information, along with recent research, I developed my topic. Knowing that certain species are more common based on elevation I wanted to see if elevation influenced the relative abundance. I will gather the elevation data of the testing sites from the GIS mapping system, and determine the abundance from the actual amounts and species of salamanders found in the field work. Currently, I do not have enough data to make any predictions because we have only sampled two locations.

We recently went on a weekend trip to sample test sites in Highlands, North Carolina. I learned about different factors that can influence data collection, the methods used in the research, and learned both salamander and vegetation identification. The weather conditions that we experienced on this trip were far less than ideal. One of the sampling days it rained and was overcast; leading to low visibility and detectability. It also increases the water level and stream flow. The second day we did not sample due to snow being on the ground. In addition to looking for salamanders at each site, we also measure the pH, conductivity, temperature, vegetation, stream bed composition, and percent undercut banks. All of these variables are measured within each five meter sampling stretch, which are separated by ten meter resting periods. In my personal research project I will also record the elevation of the test site, calculate the relative abundance at each site, and analyze the data in order to make a conclusion on my personal research project.

This Creative Inquiry provides undergraduates with an opportunity to participate in field research that may not be done in classes. The personal projects give us the opportunity to design and conduct our own research, which is a very important skill in the Wildlife and Fisheries Biology field. I have learned much more actually going out in the field and doing things related to this class than I have in a lecture. This class gives us the opportunity to apply methods learned in class to the field: an imperative skill to have when entering the professional world. 

Salamanders and Exurbanization

The following is guest post by Kevin McLeroy, a senior at Clemson University enrolled in Dr. Barrett's Creative Inquiry course focused on amphibian conservation.

After two months of participation in Clemson’s Creative Inquiry project on salamanders, I have learned exactly how much work goes into designing a research project. These first weeks spent on this project have been dedicated to developing an understanding of why salamanders are important to our ecosystems, how they can indicate the quality of the environment they live in, and what effects humans can have on them.

Our group’s research, directed by Clemson University graduate student Nathan Weaver, focuses on the effects of urbanization on the populations of salamanders. Our weekly meetings have focused on other research projects related to salamanders, such as what kind of stream habitats they prefer, the effects of buffer zones around the streams they live in, and effects of UV radiation on amphibian eggs. Reading and discussing these papers not only gave us some background information about amphibian ecology, but they also gave us an understanding of the details involved with designing a research project. Besides the actual field research, you have to find your research sites, get permission from landowners to use the sites, and make sure they are suitable for your project.

The main reason that salamanders are so intriguing is their ability to indicate the state of the environment. Salamanders are useful in this regard because their skin, like most amphibians, is very permeable, which means that chemicals from the surrounding environment will get into their bodies more easily. In addition to their permeable skin, salamanders also live 8-10 years, so they can show the long term environmental history of their habitat. Because salamanders live in aquatic habitats, they are directly affected by changes in water temperature, depth, and pollution.

On March 1, 2014, our group went with Nathan to inspect some of the field sites. Before the trip, Nathan used GIS to find first order streams located within these exurban developments. It was an all-day adventure spent driving around the Highlands, North Carolina area where a good amount of the field sites are located and making sure they are suitable. Unfortunately some of the sites we had planned to use were unavailable because they were located on private roads. It was important to make these trips in advance of our research because if the majority of the field sites were unsuitable, then our research would not be credible.

Our first sampling trip did not go as we had planned. The heavy rain in Highlands, North Carolina went on for most of the day, which decreases the detectability of the salamanders. Because salamanders live in aquatic habitats, they are more likely to hide in the event of rain as to not be swept away by the current. However, we sampled one stream and found barely any salamanders, but another stream we sampled yielded many Blue Ridge Two-Lined Salamanders. These salamanders are better adapted to lower levels of dissolved oxygen, so they persist in urbanized streams. However, the fact that only one species was detected speaks to the lack of species diversity caused by exurbanization.

Everyone has different ways of loving nature, and increasingly more people are flocking to private mountain communities with stunning views and beautiful golf courses. However, most people living in these communities do not realize the impact that their homes are having on the environment. These communities have changed the landscape, and we will see the effects of this in the coming years.  

For my personal project within the creative inquiry, I wanted to focus on the direct effect that water quality would have on the populations, but I have reconsidered and now want to address stream composition. When these communities are built, actions are taken to alter the direction of stream flow, which results in undercut banks, different stream bed composition, and different vegetation around the bank. Since salamanders prefer to live under rocks on the stream bed, I would like to see what effects the redirection of streams has on the abundance of species.

I am excited for all of the future sampling trips and continuing to learn more about the effects of exurbanization on salamanders!

What this Creative Inquiry Means to Me

The following is guest post by Meghan McDevitt, a junior at Clemson University enrolled in Dr. Barrett's Creative Inquiry course focused on amphibian conservation.

Every summer, my family would pack into our car and drive ten or so hours to the Appalachian Mountains. North Carolina is where I spent my childhood when I wasn't in Pennsylvania. I have such a love for this place and all of the diverse wildlife. The mountains seemed to come alive when we would go out hiking or rock hopping, and I was mesmerized by the amount of rainfall every summer. Starting at a young age, my brothers introduced me to the world of amphibians and aquatic insects. We would spend all day looking for big salamanders and "crawdaddys," enjoying all that nature had to offer. This passion for the outdoors has been carried throughout my life and has led me to where I am today: in a science-based major, studying salamanders and ecology in my free time. Going to the mountains feels like going home and I get to do this with an awesome creative inquiry.

My interest was enhanced when I entered middle school. When most were taking normal classes with all the other students, I was with 40 sixth and seventh graders in a program called Streamwatch. This was a two-year curriculum for those passionate about the sciences. We got to learn about watersheds, plant life, invertebrates, and various information about stream studies, as well as course subjects. This was heaven for me; I got to spend two years with such interesting students, dressing up as caddisflies and mayflies, changing fish tanks, and best of all, studying streams. Every other week, we took trips to our local watershed system and performed fieldwork in the streams. This was my first experience with hands on research and I loved it. While everyone else was a bit hesitant around the worms and larvae, I was immersed in the algae and macro invertebrates. It wouldn't be a field trip if I didn't come home covered in algae and dirt. The data collected went to the Chester County Parks system, and we'd collect all sorts of information from stream flow to pH and salinity. This is what sparked my interest in stream ecology.

The passion for science continued throughout my school years, resulting in me taking biology twice in high school (just because I enjoyed it so much) and being a teacher's assistant for biology. Coming to Clemson, I knew I wanted to be doing hands on research and be active in the field. Though I got off course switching from Biological Sciences to Engineering, I got right back on track Sophomore year changing to ENR: Conservation Biology. This is exactly what I can see myself doing in the future and is right up my ally. When I heard about this creative inquiry, it was like stepping back into my six year old self. I was ecstatic to be working with salamanders in the mountains, fusing both my passions and interests into one course. So far, I have thoroughly enjoyed the class. The students are all open-minded, interesting, and nice people. We work well together and can get things done while still having fun. Going out to sites is also such a great experience because we get a feel of what it's like to perform research in the field. This creative inquiry has opened my eyes to all sorts of topics to work in and I am so thankful for the opportunity. I love being able to use my plant taxonomy skills and acquire even more knowledge about wildlife biology, stream ecology, and the Appalachians. I am looking forward to the more semesters to come with this class as well as the research over the summer. This is such an interesting research topic and I will definitely apply it to real life situations, for example, reminding my family about this issue and making changes at our mountain house to prevent any more damages.