Hi, all. Welcome back to WTW. First of all, here's my abstract. It reiterates what I wrote in my previous post:
The Fremont cottonwood (Populus Fremontii) is a keystone species, but the number of Fremont cottonwoods is decreasing rapidly primarily due to the grazing of domestic cattle. Planting Fremont cottonwoods is an important part of restoration projects of riparian environments in the American southwest. Dozens of Fremont cottonwoods with different physiological properties were grown in gardens across the state of Arizona at various elevation and latitudes. Over the course of two years, leaves were collected from the Fremont cottonwoods in the common gardens. These leaves were dried, ground, and tested with mass spectroscopy to determine their carbon-12 to carbon-13 ratios. The carbon-12 to carbon-13 ratio of the leaves of a tree is a robust indicator of that tree’s water-status, how dehydrated that tree is. This is true because trees intake carbon dioxide for photosynthesis, but they prefer to use carbon-13. Photosynthesis also requires water. When trees are willing to expend water to perform photosynthesis with carbon-12, it means that water is abundant, and when trees are not willing, it means that water is scarce. Considering the carbon-12 to carbon-13 ratio of these trees and climatic data over the course of two years will provide a detailed picture of which physiological traits are most advantageous in different climates. This information will make environmental restorations more effective, which will help alleviate the ecological and economic harms of raising cattle like larger wildfires and the endangerment of native species.
In addition, I wanted to write some more about photosynthesis. There are the light-dependent reactions, which can be thought of as providing the energy for building large carbon chains, and the light-independent reactions, which form a carbon chain. Because scientists like dividing things, the light-independent reaction itself has three parts: carbon fixation, reduction, and regeneration. These are all very complicated, but I'll try to put it as simply as possible. Carbon fixation is the process of incorporating inorganic carbon into organic molecules. Practically, this means carbon dioxide joining with a molecule called RuBP (Ribulose-1,5-bisphosphate). The process of reacting carbon dioxide with RuBP is called a metabolic pathway. There are three different metabolic pathways, all of which involve the reaction of RuBP and carbon dioxide. They are C3 (the most common), C4 (the weird one), CAM (the one for hot and dry areas). The differences are SUPER complicated, but here's the main difference. C3 is one step. C4 and CAM are two steps. Each step uses enzymes. Enzymes don't like carbon-13. In C3 it is like having one filter against carbon-13. With C4 and CAM, it is like having two. Luckily, these enzymes are a predictable filter, which allow us to quantify an expected carbon-13 to carbon-12 ratio.
That's all for now. Sorry for all the detail. I promise all this info is working towards something cool, and I swear next week's post will be an easier read.
I really enjoyed learning more about the Populus Fremontii. It seems like you are very interested in your work, and I hope to see what you do next week!
ReplyDeleteWow, that's a lot of cool information! I have a few questions: What if water and C-13 are both scarce? Will the tree try to use C-12, or stick to searching for C-13 so as not to waste water? And if enzymes do not like C-13, then why do trees prefer to use that?
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DeleteZiba, excellent questions. An assumption of this procedure is that carbon-12 to carbon-13 ratio in the air is pretty much globally uniform (and this assumption works pretty good with empirical measurements).
DeleteIts interesting how plants have different physiological properties depending on where you plant them. Would it help to look at desert plants compared to other plants to see how it uses less water more efficiently to survive?
ReplyDeleteThat's a really good question, Angela. There are several adaptions that desert plants have to preserve water, and identifying them is incredibly usefully in understanding the evolution of plants. As to weather that is useful for this project, probably not. However, you see some microadaptions in cottonwoods that amplify traits that the cotttonwoods survived to live in a dry climate.
DeleteHi Brian, this was a cool post! And don't be sorry for the detail... I quite liked it. It was easy to read and understand. Your choice of plant was interesting to focus on. You seem to be very eager in the subject, which is great!
ReplyDeleteHi Brian! I was really interested to read this post! It seems as if you're working hard and are quite focused on this. I loved reading about your choice of plant, and it was especially interesting to learn about the different places and conditions on species can be planted in! I'm looking forward to next week's post. :)
ReplyDeleteHey Brian, I remember learning about keystone species last year, but i somehow completely forgot how it impacts an environment. Could you refresh my memory? Also, what caused you to conduct your research on Fremont Cottonwood instead of another keystone species?
ReplyDeleteKeystone species are especially important to their environments. Many animals live in the Fremont cottonwood.
DeleteHey Bryan, I really enjoyed reading this week's post. I found it interesting how scientists use mass spectroscopy on plants. This week's post has sparked my curiosity and I can't wait until next week's post.
ReplyDeleteYour work with plants and carbon isomers is really interesting. I'm exited to see what you do next week!!
ReplyDeleteYour post was pretty detailed. How does your work relate to ecological restorations? Also, is there some specific issue with raising cattle that leads to more wildfires and species endangerment?
ReplyDeleteThe goal of the project is to be able to identify which trees are the best to plant during ecological restorations. If we can tell which type of trees are the least water stressed in an environment, then we can improve the efficiency of restorations.
DeleteHi it's Saaketh. I liked learning about the details of photosynthesis, and about mass spectrometry. It seems like you are really getting deep into your project. I can't want until next week!
ReplyDeleteHi Brian,
ReplyDeleteYour explanations of mass spectroscopy and carbon fixation were very detailed yet concise which helped me actually understand what was going on. I can tell you are very interested in what you are researching. Can't wait to read next week's blog!