A sad farewell

1. I understand that the purpose of the project was to measure different rates of carbon consumption by bacteria using different types of carbon found in natural inland water systems. We were trying to imitate natural water systems to better understand their role in the carbon cycle. Our results show that previous conclusions stating that autochthonous carbon is a more labile source of carbon for certain bacteria may be incorrect because there was not a significant difference in the rate of consumption between the two systems we tested. Statistical analysis was used to determine differences because the initial amount of carbon in each system was different. 

I gained skills that allow me to understand how research is conducted and how to make a poster. I thought that I was not creative enough to come up with a research question on my own and that I would never be able to call myself a real scientist but this class showed me that it is completely possible for me to do in the future. 

Posters are a different method to conveying information than teaching to high schoolers because it cuts out introductory information and only displays the important pieces of the project. It explicitly shows how the research was done, why it was done, and what was found. When teaching there is a hidden agenda where you want to make the kids care about the information and what it means to them but a poster does not display that facet of thinking. It is easier to have a poster because other people can read it and if they have questions you can answer them instead of having to predict what questions will arise and answering them before they are asked.

2. My presentation skills definitely improved. I was not able to stand in front of a group of people, even just two people, without panicking. I guess I still panicked on teaching day but it got better as the day progressed.

I think that I put my presentation together well after a lot of help from Eric and feedback from practicing. I think I still need to improve getting my anxiety under control.

The hardest part about teaching was preparing the lesson.

The lecture from the school of education was awesome. Teaching is a complex practice and it involves thinking about things on many different levels. For instance, you can think that you have come up with a great concept to teach and make a lesson for it but the students may not understand anything you taught if there wasn’t enough clarity in the lesson or if you present the information in one form and don’t differentiate teaching methods.

It is difficult for me to say which module I was most comfortable with because I was not able to present all of them. I enjoyed making the why do we care presentation because I think that part of it really brings the whole lesson together and makes people care and want to understand what is happening on our planet.

3. To learn the material I read the research papers we were assigned, I visited other informative websites when I had questions, I asked questions in class, I went over the powerpoints we were given, and completed the same worksheets that the students completed.

I was comfortable with most of the information by the end of the semester and I can’t think of anything else that could be done.

Practicing the presentation in the classroom with feedback from Eric and Abby was the most effective strategy for my preparation. It showed me what I was doing right and wrong and what I needed to change in my presentation. Reflections on presentations were also very helpful because I was able to really sit and think about every aspect of the presentation and what it meant.

Simply reading over the material and not orally practicing the presentation was least effective in preparing. A suggestion for improvement would be to practice the presentation over and over to a third party audience who may not know about the subject to make sure they understand the material presented and that the presentation flows properly. 

4. I really liked that this was a small class. It made things very personal and intimate. It made me feel comfortable to be around you and comfortable to ask questions when I didn’t understand something. This helped me to learn and perform better. I also really liked that I was forced to reflect on my work. I think reflection is an important part of the learning process. I very much enjoyed flexible deadlines because it made things much less stressful if I was able to complete an assignment when I had time. Usually I dread doing assignments and procrastinate on them but the blog posts were not difficult assignments to complete and I really think they helped my development and growth in this class. I wish the high school students had more time on the field trip. I wonder if there would be a way to do the first introduction portion in their class and then do the field trip the next day to the rice center for the rest of it in order to spread out the material.

5. This class has been immensely influential in helping me to become a successful teacher. I will be able to use the skills I learned in this class to help me better prepare lessons and teach students about complex ideas through project-based learning. As far as other aspects of my life, I can use the information I have learned to be a more environmentally-friendly person. We are now recycling in my apartment after I did research into how to go about getting sidewalk pick-up and learning what I could and could not recycle. This class taught me that you don’t have to picket and lobby politicians to try and change laws concerning the environment. I used to be a part of Green Peace but I did not like their methods at all. They were essentially stalking the representative from Northern Virginia in order to influence his vote. They showed up to personal events in his life including his nephew’s birthday party. I thought that was so trashy and inconsiderate and definitely not the right methods to use in order to change policies. Research and facts are much more influential than an angry dread-head yelling at an old man in a suit. 

6. I had learned about the carbon cycle and photosynthesis and respiration in Biol 151. We went over carbon emissions and the greenhouse gas effect in Chemistry and Society. However, I was not able to retain the information as well nor was I able to fully understand the depth of the concepts until I took this class. 

7. At first, I didn’t think I was going to like the blog at all and that it was just going to be unnecessary extra work. However, as time passed I realized that the blog was actually a very helpful tool to use in order to do homework assignments and reflect on our learning and progress in the class. It also helped to me to research appropriate primary sources to use in our project. I read all of the blogs that were posted because I love procrastinating and looking at crazy stuff on the internet. I loved that Abby was very proactive with her blog at the beginning because I was able to read a lot of cool stories and news articles. Some random person re-posted one of my blogs and it made me feel so cool. My ego grew three sizes that day. I couldn’t believe that someone would want to read the things I write, much less show other people. It was empowering and built my confidence. I thought the topics were very helpful because they forced me to research the subject and learn new things. I also would have liked if we had to do something like a “carbon in the news article” every week along with our other blogs too. Not too much work but just enough to make blogging fun and interesting.

8. I already knew that carbon was an incredibly important element on Earth and that it was heavily influential on global warming and climate change. I think that since I am now able to explain in detail how carbon emissions affect global warming, I will be able to silence critics and nonbelievers with the facts rather than just saying that its happening without knowing why. It has changed my habits because I now understand that recycling is an important practice and not just something that hippies do. I thought that I had a small carbon footprint because I either walk or ride my bike most places but now I see that I am so wasteful and I produce so much garbage. Where did I think that garbage went? I am the worst.

I put a picture of a sad kitty because I know Abby likes kitties and because I am very sad to be done with this class. I think that I will be able to take a lot more away from this class than just information on the carbon cycle. I enjoyed telling people that I was working on a research project because it made me feel important and cool. I also like telling people that I have to go to the lab because it makes me sound mysterious and smart. It makes me feel like I am actually accomplishing something with my time in college. Working on this research project has given me the confidence to think that I will be able to work on other important research projects in the future which is something that I did not think I was capable of doing before. Most of all, I will miss you guys. It has been a pleasure getting to know you both. I have not been able to be so personal with anybody in any of my other classes. I hope to see you both around campus.

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The results are in!

Image

 

 

The results:                      Sunny                         FOR                                 JR                              FPL

pH                                    7.25                              6.45                                7.7

Temp (C)                         17.5                              17                                   19.5

DO                                   8.8 ppm                        <2 ppm?                          7.3 ppm

pCO2                               310 ppm                       3600 ppm                         440 ppm

chl a                                 259.20                          107.16                              36.52                      67.7

Avg DOC consumed         2.0133                          2.657                                0.2637

Avg DOC T=0                   72.54                            23.063                               4.382

 

Hypotheses Supported or refuted?

H1: There will be a greater loss of DOC in the forested post-leaf fall than the forested pre-leaf fall due to the fresh source of allochthonous carbon. – We do not know this yet because we do not have information for the post-leaf fall mesocosm yet. 

H2: There will be a moderate loss of DOC in the Sunny mesocosm due to a labile source of autochthonous carbon (Eiler, 2004). This is supported. Define moderate though? This hypothesis may need to be reworded. Moderate in comparison to the forested? The results show that there was less DOC in the forested mesocosm to begin with (there was 31.8% of the amount of DOC in the forested as in the sunny) but there was a comparable amount of DOC consumed (actually it was slightly more) to the sunny mesocosm. The James River had a much much lower amount of DOC to begin with and we see that there was a much much lower amount of DOC consumed over time. There was 6% of the amount of DOC found in the James River as was found in the sunny mesocosm. However, there was a higher rate of consumption in the James River than in the sunny mesocosm. We see a lower rate of consumption in the James River than in the forested mesocosm but a higher rate of consumption in the James River than in the sunny mesocosm. The James River is more similar to the sunny mesocosm than the forested mesocosm in the amount of DO and pCO2 measurements. However, there was more chl a found in the forested mesocosm than in the James River suggesting that there was less algae (or autochthonous carbon) available in the James River than in either of the two mesocosms. So, the question I am stumped with in the end is: If there is not as much photosynthesizing algae in the James River than why are the DO and pCO2 measurements similar to a mesocosm where photosynthesis dominates and where there is a significantly larger amount of algae?

H3: The rate of consumption of DOC in the James River sample will be less than the forested mesocosms due to the natural system size and a mixture of both sources of carbon present in the sample. This hypothesis is supported by the results. The natural system experiences active transport of water and we can infer that it also experiences active transport of carbon sources throughout it’s system. The mesocosms do not experience natural water movement. They simply experience overflowing when it rains. I believe that this difference affects the results we have obtained. I think the reason the mesocosms had higher levels of DOC, chl a, and probably higher amounts of bacteria and algae is because these organisms have the ability to colonize without migration making a large population in a small area. DOC can not be buried and unburied in sediments in the mesocosms like it can be in the natural system.

It appears that the bacteria prefer the allochthonous carbon sources. Or at least there was a higher consumption rate in the forested mesocosm than in the sunny mesocosm. However, according to the Kruskal-Wallis post-hoc test, it was determined that there is no significant difference in the rate of DOC consumption between the sunny and forested mesocosms. This means that bacteria do not have a preference for autochthonous carbon as previously thought. This would go against the findings of Attermeyer et al. who stated that increasing authochthonous sources of carbon into a system versus using allochthonous carbon increased carbon consumption by the bacteria. They suggest that the authochthonous sources are more labile than the allochthonous sources of carbon. However, our experiment shows that there is no significant difference. It will be interesting to learn the difference between the forested post-leaf fall results compared to the other samples to determine whether a freshly fallen leaf is more labile than a decaying leaf or a fresh algae corpse.

Attermeyer, K., Hornick, T., Kayler, Z. E., Bahr, A., Zwirnmann, E., Grossart, H.-P., and Premke, K.: Increasing addition of autochthonous to allochthonous carbon in nutrient-rich aquatic systems stimulates carbon consumption but does not alter bacterial community composition, Biogeosciences Discuss., 10, 14261-14300, doi:10.5194/bgd-10-14261-2013, 2013

 

This research and the results found have notable implications on other research related to the global carbon cycle. We have found information that refutes former thought and should be taken into consideration when calculating the amount of carbon that is actively cycled through the Earth’s inland waters. Inland waters in forested areas such as swamp lands, vernal pools, and streams apparently cycle a comparable amount of carbon to lakes, large rivers, and less shaded water systems. More accurate data can lead to better mitigation methods that attempt to balance the global carbon budget. 

Further experimentation that could be done would be to calculate the rate of consumption in the sunny mesocosm before the algae dies and after algae dies. We can visually see on our graphs that the rate increases after the algae dies but do we know if this happens because there is more DOC available or if the fresh source of dead algae is more labile as well. If there was a way to make a mesocosm that actively cycled water and contained sediments and larger organisms that mirrored the natural system it would be beneficial to add this to the experiment. I think that it would be interesting to know how well the mesocosms we already have are able to act as pieces of the natural systems we wish to measure. How can we really estimate the sources of carbon in each system and the rates of consumption accurately when every inland water system is affected by a number of different variables? I think that it would also be interesting to know the kinds of bacteria in each system. I would isolate the bacteria found in the James River and do smaller-scale experiments to see how different kinds of bacteria found in the river are affected by the different sources of carbon and maybe go on to further experiment with how seasons and other variables can affect the rate of carbon consumption as well.

Self-fulfilling Prophecy: A reflection on teaching

 

I had felt fine all morning but as the time drew closer for the students to arrive my stomach began hurting. The more my stomach hurt the more anxious I felt. Then the more anxious I felt the more my stomach hurt. It was a terrible cycle which resulted in me being completely embarrassed of my visible anxiety. 

I know that I was not able to say everything during my presentation that I had planned on saying and I wasn’t able to ask all of the questions I wanted to either because I simply forgot what I was doing since I was focused on myself. I knew going in there that I was going to do that and I had tried to prepare myself mentally to think about the students and the lecture and not about myself. But, I lost the battle inside my brain when it finally happened. I was a victim of the self-fulfilling prophecy where the outcome happens as you perceived it was going to happen prior to it happening. “If men define situations are real, they are real in their consequences” -W.I. Thomas (R.K. Merton 1948) However, as time went on the whole process became a lot easier. The students were very supportive on top of being generally awesome kids. 

I realized that I had been very pessimistic about the students desire to learn and their desire to be there. When I was in high school I was very shy and I put on apathetic airs to cover the fact that I was just completely uncomfortable due to a debilitating case of social anxiety. I always acted uninterested, especially if the material was difficult to understand. I would give up instead of trying. So, I thought the students from Hopewell were going to be the exact same way. It was completely the opposite. Some of the students did admit that they were there because it allowed them to skip their other classes but they were all very enthusiastic anyway. They did not come in with a lot of knowledge on the subject, or rather they didn’t think they had a lot of knowledge on the subject. By the end of the day they were correctly answering questions about the complexities of the carbon cycle. It seemed to me that once they were given the pieces of the puzzle they were pretty much able understand everything that was happening. I also didn’t think that they would want to go outside and mess with the water since it was freezing that day but they were really good sports about it. We had some trouble doing the dissolved oxygen kit. I wish I had gone back over the directions that morning so that I could walk them through each step without confusion of my own. I also dropped one of the water samples on the ground ruining the test and looking unprofessional doing so. 

I was very grateful to the students for paying attention to me, laughing at me, and working diligently without complaints. It felt good. It gave me hope that when I do become a teacher, my students will listen to me. As of right now the middle schoolers I work with do not treat me like an authority figure but rather as one of their own who knows all of the answers. I wish I had gotten as much attention from eighth grade boys and invitations to the girls’ birthday parties when I was 12 as I do now that I’m twice their age. 

I think that the excel presentation will go a lot smoother and easier because I have already had contact with the students and have seen that they will work and listen if told to do so. 

I think that it is hard to understand where each student sits in their personal understanding of the subject when you are the teacher. When I would ask a question someone would answer correctly so I would assume that everyone understood. Then when I went to work on the the worksheet with one of the tables I realized that not every single student understood just because that one who answered correctly did. However, as a student I can see differing levels of understanding clearly in my classes. I know that some students get it while others don’t. I never realized that teachers don’t see that as clearly. I feel like I should stop answering questions in my classes and let the students who do not understand get caught up, or I should be more audible when I personally do not understand something even though the other students do. I learned in my teacher preparation class that differentiation can help teachers better guage where each student is at. Differentiation is tailoring your lesson plans and instruction in order to meet varied needs in the classroom since students learn at different speeds and by different stimuli (C.A. Tomlinson 2000). This is a critical tool to use in developing lesson plans and we utilized it even if we didn’t realize it. We did lecture-based learning, worksheets that involved reading, writing, and problem-based learning, as well as a hands-on approach by physically bringing the students to the mesocosms and testing the water samples. 

I hope that the students retained the information that they were given on this field trip (even though it was so much information in such a small amount of time) and had fun as well. Even if they did not understand everything, hopefully the teachers can use the field trip as a reference aid when going back over all of the processes of photosynthesis and respiration. 

 

 

Merton, Robert K. “The self-fulfilling prophecy.” The Antioch Review 8.2 (1948): 193-210.

Tomlinson, Carol Ann. “Reconcilable differences: Standards-based teaching and differentiation.” Educational Leadership 58.1 (2000): 6-13.

R-r-r-r recycle rap

http://youtu.be/u3RNbq51ayY Here’s a fun song about recycling.

When I was in first grade I was in a school play about recycling. We sang the recycle rap. I was a trashcan. Unfortunately there are no pictures or video to prove it.

 

The most interesting thing I found about the presentation was that you can’t put greasy pizza boxes in the recycling because they can contaminate a whole line of recyclables. After I heard that I was walking down the street and examining people’s recycle bins. “Don’t you know you can’t put that in there!?” I honestly didn’t know that. 

I was surprised by the difference in the amount of people in the VCU/Fan area who recycle compared with the amount of people outside of this area who recycle. I am also surprised by the fact that Virginia has such a low rate of recycling compared with the rest of the U.S. What’s wrong with us? How come other states can get people to care but here in Virginia we’re like whatevs, long hair don’t care.

I think there are many reasons why people don’t recycle. I think one of the biggest reasons that can easily be fixed is that they don’t know how to go about doing it and they are not really sure what they can and can not recycle. I also think people don’t understand the magnitude of trash that we create and the resources we are constantly using. In this area, you have to pay to recycle just like you have to pay for trash pick-up or to bring trash to the dump, and for a lot of people that is too much. If it is not something they have to pay regardless of how little the fee is, then they will not pay it. 

18-25 year olds are generally naive. I learned in the last five years many things that adults take for granted such as you have to change the filter in your vents on a monthly basis or windows without curtains lose a lot of heat in the winter. My trash and water bills are included in my rent and I wish recycling was too and I wish I could be given a pamphlet that teaches me what is acceptable and a weekly reminder to tell me to put the recycling out. If my trash wasn’t a public use bin I would forget to put it out every week. I mean how many times have I forgotten to move my car for street cleaning and that’s a 40$ ticket. I think that most 18-25 year olds do not have any kind of strict schedule and their lives are usually pretty hectic. Did I remember to brush my teeth today? We also usually have pretty small apartments and it is difficult to allow recyclables to build up over a two week period. 

Here’s an interesting news blog that tries to outline why many people don’t recycle:

http://earth911.com/news/2010/10/25/why-people-dont-recycle/

 

I wish the CVWMA would be more proactive about getting people to recycle. I think they could approach landlords of large buildings with information on recycling and try to make a deal where recycling can be included in monthly rent. I’ve noticed that they take an approach where they give talks and information to elementary schools which is good to teach the children at an early age but I feel that they have neglected to reach the parents of those children and haven’t followed up with the kids as they get older. Maybe high schoolers should have to take a home economics class that teaches about finances and waste management instead of learn how to make pancakes. I think a class like this should be mandatory. I think it should also prepare students to make resumes and train them how to act like human beings so they can get jobs too. 

I think some of the barriers that CVWMA faces is that they could get more people to recycle if they could do more curbside pick-up but that would mean they would need more trucks and more workers. Recycling doesn’t seem to be a very profitable business in the first place. According to Geraldine Sealey of ABC News, Mayor Bloomberg of New York is planning to save $57 million by not recycling glass, plastic, and aluminum for 18 months. (http://abcnews.go.com/US/story?id=91824) Economic planners do not seem to think that recycling is worth it. Some critics even believe that it is a load of phooey and that the amount of trash we create is not exactly “Earth-swallowing”. Tell that to the trash island the size of Texas floating in the Pacific Ocean! http://en.wikipedia.org/wiki/Great_Pacific_garbage_patch Sorry for Wikipedia!

I have no idea how to make recycling profitable. I know that CVWMA sells their products to various companies which is outstanding but when is Campbells or that major paper company from The Office going to jump on the recycling bandwagon and buy from recycling plants to redistribute in the local areas it buys from instead of paying for deforestation and the mining of metals?

Did you guys ever see the movie Wall-E? If not, you should. Idiocracy? Not as good but still relevant because it is also accurately and scarily predicting our future. Just kidding. Kind of.

 

Excel Presentation

 

Strengths

I think my strengths in this presentation were that I was able to explain most (not all) of the material clearly and also that I was able to smoothly guide us through the excel steps. 

Weaknesses

I think my weaknesses were that I was not able to clearly explain what standard deviation and what a t-test are. Also, I think I could have spent more time in the introduction reviewing the experiment we did and why. Not having the t-test calculated out correctly hurt my presentation as well. I think I need to go back over that myself and make sure I explain each step concisely.

Preparation

My preparation included going over each slide and deciding what I wanted to say. I also used a cheat sheet during the excel portion to guide myself through each step and make sure I didn’t miss anything or do anything incorrectly.

How Improved

I think that this presentation was easier to give because the powepoint and excel spreadsheet were already made for me and the process was already laid out for me and I just had to follow the steps. Since this presentation felt easier it was a lot easier to get up and do it. Even though my preparation time was not anywhere near as much as I prepared for the carbon cycling presentations it went a lot smoother. I didn’t have to constantly remember where I put things and why. I didn’t have to spend large amounts of time explaining complex systems and fear that I was explaining it incorrectly. 

Since the first presentation I think that I have realized more that I am explaining this information and doing this presentation for students rather than giving a presentation to explain to a teach what I know. This makes my presentation skills more comfortable. I also think that as I have spent more time with students I am starting to be able to guage how they respond to certain structure and stimuli. It is helping me to be able to see when they are completely confused as to what I just said which tells me I need to re-explain it a different way.

As I was looking for a nice image for this post I came across a structured planning method that analyzes strengths, weaknesses, opportunities, and threats involved in a project called SWOT (Humphrey 2005). SWOT analysis is mostly used in marketing and business ventures and is encouraged by the HR departments to help employees work efficiently on projects. I think the same method can be used when giving presentations and working on this project together as well. 

  • Strengths: characteristics of the  project that give it an advantage over others
  • Weaknesses: are characteristics that place the team at a disadvantage relative to others
  • Opportunities: elements that the project could exploit to its advantage
  • Threats: elements in the environment that could cause trouble for the project

Although we are not competing against anything we can still use this method to identify the good parts and bad parts of our presentations as we are doing them in order to perform better.

How to Engage Audience

In order to engage the audience I am going to try and ask them as many questions as I can and try to force participation and answers out of them. I am also going to make sure that everyone is on task and understanding what to do by asking for confirmation between steps and walking around the class to check over their shoulders as they work. I do not know how to make this portion of the project more exciting other than to relate it back to the overall study and questions.

Abby’s Presentation

I thought that Abby did a nice job explaining what the numbers and results we got were. She continually asked the students what it meant and that was good because it made them think about what was happening. Abby explained the introduction part of the presentation very well. I think that during the excel portion the thing that hurt her presentation the most for me was her speed. I was trying to go through the steps of the excel with her but I was not able to keep up sometimes. However, I think that when she is actually in the classroom with the students her pace will be fine since she will know that everyone is trying to follow her directions. 

 

 Humphrey, Albert (December 2005). “SWOT Analysis for Management Consulting”SRI Alumni Newsletter (SRI International).

Critique of the Class

 

 

I think that this class is great overall.

 like that it is very small making it easy to get teacher feedback on your work. However, sometimes I do not like that this class is so small because I enjoy anonymity and I do not like that if I am late to class that I actually affect the whole class. But then again, it forces me to not be late and to do my work because if I don’t then I am not only hindering my learning but also Abby’s learning and Eric’s ability to teach. There was a study done over a period of 25 years called STAR or student/teacher achievement ratio. The study found that that small classes provide short- and long-term benefits for students, teachers, and society at large. Although all students benefit; poor, minority, and male students reap extra benefits in terms of improved test outcomes, school engagement, and reduced grade retention and dropout rates (Blatchford 2011). I really like getting individual attention in the classroom and it makes learning the material and doing the assignments easier. 

 

I love that we get to go out to the RICE center as well. It makes me feel important and it is beautiful out there.

I think that the timelines on all of the assignments have been appropriate and have not caused too much stress or anxiety. One of the things I wanted to get out of this class was to become more comfortable in front of a large group of people giving an presentation. I also wanted to see how much work goes into teaching a lesson well. I think that I will be able to achieve both of these goals before the end of the semester. My level of comfort giving presentations can only be eased with preparedness. 

I think the service learning aspect of this course is incredible. I think that it will go a long way not only on a resume but also as experience for a future career in teaching. I wish my high school had cool research-based field-trips like this. 

The actual project we are working on is interesting as well. Working on it makes me feel like a real scientist and sparks ambition to go out and do other research as well. 

I think this class is very unique and a fantastic opportunity for anyone involved. There are not many negative aspects of this class except for those that stem internally from myself. 

 

Blatchford, P. (2011). Three generations of research on class size effects. In K.R. Harris, S. Graham, & T. Urdan (Editors-in Chief). Educational psychology handbook (Vol. 2: Individual differences and cultural and contextual factors, pp. 529-554). American Psychological Association: Washington, DC.

Hypotheses

Hypothesis: There will be greater DOC consumption in the forested mesocosm post-leaf fall and in the forested mesocosm prior to leaf fall than in the sunny mesocosm. 

Justification: There is more active heterotrophic bacteria to consume the DOC. The forested mesocosms are dominated by heterotrophic bacteria but the sunny mesocosm does not have as much heterotrophic bacteria to consume DOC because it is dominated by autotrophs.

In waters with low primary production and a high supply of terrigenous material, allochthonous carbon can be a major energy source for bacteria as we see in the forested mesocosms (Tranvik 1988, Kuparinen et al. 1996).

 

Hypothesis: The sunny mesocosm will begin with higher levels of DOC and will see a spike in DOC amount and the rate of consumption as the algae dies but bacteria does not.

Justification: In past experiments we see that there is a much higher amount of DOC to begin with. The algae will die due lack of sunlight in the dark containers and add to the amount of DOC but the bacteria will survive by eating the dead algae and other DOC because it does not need the sunlight as much to survive. According to Moran and Hodsan (1990) dissolved organic carbon supports bacteria growth and sustainability in limnic and marine environments. 

Hypothesis: There will be greater DOC consumption in the forested mesocosm post leaf fall than in the forested prior to leaf fall.

Justification: Humic acid is a principal component of humic substances, which are the major organic constituents of soil peat, coal, many upland streams, dystrophic lakes, and inland waters. It is produced by biodegradation of dead organic matter (Stevenson 1994). According to this study, http://www.int-res.com/articles/ame/17/a017p289.pdf, researchers have found that terrestrial organic matter containing substantial amounts of humic matter which freshly fallen leaves would develop overtime through degradation in the samples, provides energy to aquatic bacteria (Wikner et al. 1998). There may be more humic matter in the sample that came from the post leaf fall forested mesocosm. 

F.J. Stevenson (1994). Humus Chemistry: Genesis, Composition, Reactions. John Wiley & Sons, New York.

Tranvik U (1988) Availability of dissolved organic carbon for planktonic bacteria in oligotrophic lakes of different humic content. Microb Ecol 16:311-322

Moran MA, Hodson RE (1994) Support of bacterioplankton production by dissolved humic substances from three marine environments. Mar Ecol Prog Ser 110:241-247

Wikner, J. et al. (1999) Differences in consumption of allochthonous DOC under limnicand estuarine conditions in a watershed. Aquatic Microbiology Ecology Vol. 17 289-299 Umea University, Sweden