In my last post, I mentioned that Summer, one of the undergraduates here, has an independent project. By this point all four of us undergrads have our own projects, although they are very different from each other and serve different purposes. Summer and Elsemarie are from colleges other than UW-Madison and are interning with the lab group through the National Science Foundation. As part of that, they are required to complete an independent project and present on it at the end of the summer. Patrick and I are both UW-Madison students and went through our school's study abroad office to get this internship. We aren't required to do a project, but they sound like fun, and it was my best chance to really work with some microbes! (Which we all know I love. a lot. I miss my microbes back in Madison).
Summer and Elsemarie have already started their projects - as I mentioned in my last post, Summer is working on the movement of zooplankton in relation to the amount of sunlight, which is expected to be different than normal because of Iceland's extended day time. Elsemarie is experimenting on spider behavior to see if spiders change their diet when the midges emerge from the lake. Patrick and I have just finished planning out our projects. Patrick will be studying the amount of productivity in the many ponds near Myvatn to see if there is a common factor among the high productivity ponds, like distance from the lake, distance from farms, or bird usage, to name a few.
I will be studying the activity of soil microbes in different productivity gradients. Remember those fertilization plots we set up? Those are placed in different productivity gradients around Myvatn, and that's where I'll be getting my samples. Productivity gradient is just a fancy way of saying different types of landscapes, with different plants and different amounts of growth. On the low end of our gradient is a lava field, which is sandy and contains patches of plants. In the middle are two types of heathland, one dominated by lichen and the other dominated by small trees like dwarf birch and dwarf willow (they come up to about knee level). High productivity is represented by a grassland.
Previous experiments have shown that high productivity is associated with high numbers of midges, presumably because the midges add nutrients to the soil. But midges don't spontaneously turn into nutrients - they are decomposed by soil microbes! We can measure how much decomposition is going on by measuring the respiration rate of the microbes. We know how much microbes respire because they release carbon dioxide while they're doing it. So the experiment is to collect soil from these different sites and to put it in a container and let it sit for a bit (fancy science term for letting things sit = incubation). We'll pull out some of the air in their containers and put it in sealed vials for analysis back at Madison. Sadly we can't get the results here because you need a big expensive machine called a gas chromatographer to measure the amount of carbon dioxide. The hypothesis is that there will be higher rates of decomposition where there is higher productivity.
I'll also be helping with soil lipid analysis while I'm here. This is a way to get an idea of what microbes are in the soil based on what lipids they produce. Lipids, otherwise known as fats, are organic compounds composed of three long carbon chains, which can have a lot of variation. Different species (including us!) have the ability to produce different types of lipids, so you can tell what organisms are present by the types of lipids in the soil. This is a great way to find out what's in there without doing DNA analysis, which is more expensive and takes longer.
Hopefully I will be starting my experiments next week! There is also the possibility that I could present on my project at a symposium when I get back to Madison, which would be really cool!
Summer and Elsemarie have already started their projects - as I mentioned in my last post, Summer is working on the movement of zooplankton in relation to the amount of sunlight, which is expected to be different than normal because of Iceland's extended day time. Elsemarie is experimenting on spider behavior to see if spiders change their diet when the midges emerge from the lake. Patrick and I have just finished planning out our projects. Patrick will be studying the amount of productivity in the many ponds near Myvatn to see if there is a common factor among the high productivity ponds, like distance from the lake, distance from farms, or bird usage, to name a few.
I will be studying the activity of soil microbes in different productivity gradients. Remember those fertilization plots we set up? Those are placed in different productivity gradients around Myvatn, and that's where I'll be getting my samples. Productivity gradient is just a fancy way of saying different types of landscapes, with different plants and different amounts of growth. On the low end of our gradient is a lava field, which is sandy and contains patches of plants. In the middle are two types of heathland, one dominated by lichen and the other dominated by small trees like dwarf birch and dwarf willow (they come up to about knee level). High productivity is represented by a grassland.
Previous experiments have shown that high productivity is associated with high numbers of midges, presumably because the midges add nutrients to the soil. But midges don't spontaneously turn into nutrients - they are decomposed by soil microbes! We can measure how much decomposition is going on by measuring the respiration rate of the microbes. We know how much microbes respire because they release carbon dioxide while they're doing it. So the experiment is to collect soil from these different sites and to put it in a container and let it sit for a bit (fancy science term for letting things sit = incubation). We'll pull out some of the air in their containers and put it in sealed vials for analysis back at Madison. Sadly we can't get the results here because you need a big expensive machine called a gas chromatographer to measure the amount of carbon dioxide. The hypothesis is that there will be higher rates of decomposition where there is higher productivity.
I'll also be helping with soil lipid analysis while I'm here. This is a way to get an idea of what microbes are in the soil based on what lipids they produce. Lipids, otherwise known as fats, are organic compounds composed of three long carbon chains, which can have a lot of variation. Different species (including us!) have the ability to produce different types of lipids, so you can tell what organisms are present by the types of lipids in the soil. This is a great way to find out what's in there without doing DNA analysis, which is more expensive and takes longer.
Hopefully I will be starting my experiments next week! There is also the possibility that I could present on my project at a symposium when I get back to Madison, which would be really cool!
Go lipids!
ReplyDeleteSounds like a cool experiment you've thought up! ;-)