2009 13 July Biology Ecology and Nutrient Cycle of the Ecosystem Post FOUR Hi! ;D This post's going to be quite long, yup. Biogeochemistry's a big topic to talk about. Haha!
Alright, no more delay, let's just start. As we all can see, the big word, Biogeochemistry, involves and is made up of mainly three words, biology, geology, and chemistry. So, we can roughly infer, that biogeochemistry is the study of biology, geology and chemistry. More specifically, it is the study living systems, us, and other living animals, are affected, influenced and controlled by the geology and chemistry around us. Hence, it includes the study of many biotic and abiotic world around us. One important use of biogeochemistry, would be to anazlyse, in the food web, which of the linkages are more important than the others. One obvious way would be to study the cycling of elements, like how each organism are controlling or changing the elements. Biogeochesmists do this in 3 major ways, and they are also the principle and tools of biogeochemistry. They are mainly element ratios, mass balance and element cycling. Alright, I will start with element ratios. Here's a quote from the site. In biological systems, we refer to important elements as "conservative". These elements are often nutrients. By "conservative" we mean that an organism can change only slightly the amount of these elements in their tissues if they are to remain in good health. It is easiest to think of these conservative elements in relation to other important elements in the organism. For example, in healthy algae the elements C, N, P, and Fe have the following ratio, called the Redfield ratio after the oceanographer who discovered it: Let me break down, what this paragraph is talking about. As stated above, important elements (nutrients) are called "conservative". So, as we know, they are not only important to the organisms around us, but also us. Hence, if an organism would to use or convert less conservatives in order for it to stay in its healthy condition, it would be more important for us, as they take up less conservatives. Next, I will talk about mass balance. Here is the quote from the site. Another important tool that biogeochemists use is a simple mass balance equation to describe the state of a system. The system could be a snake, a tree, a lake, or the entire globe. Using a mass balance approach we can determine whether the system is changing and how fast it is changing. The equation is: In this equation the net change in the system from one time period to another is determined by what the inputs are, what the outputs are, and what the internal change in the system was. The example given in class is of the acidification of a lake, considering the inputs and outputs and internal change of acid in the lake. Basically, this method is to find out what is the change of a certain system, and the rate of it changing. Net change basically means the original change of a certain system, without other factors disturbing it. The example above given was a lake, hence, the input could be what humans are doing to the lake such that it is becoming more acidic. The output could be what humans are doing to help the lake, such that its acidity level decreases. Lastly, the internal change would what is happening inside the lake, that causes its acidity level to increase or decrease, or fluctuate. Lastly, element cycling. It is basically to find out how fast nutrients or elements are moving in a system, and as I have explained before, there are two types of system, an open system, and a closed system. A recap, a closed system is where inputs and outputs are minor compared to the internal change. An open system is when inputs and outputs play a major role together with the internal change. To measure the element cycling in a closed system, we take a look at two things. The rate at which is going, which is basically the amount of cycles divided by the time needed to make all the cycles. Secondly, we can at the pathways where the elements are going, this is important as different pathways can cause different chemical reactions to the elements. To measure the element cycling in a open system, we use both rate and pathways, with a new factor included, with is the residence time. As in an open system, the inputs and outputs are considered, residence time would measure how long a element is staying inside a particular system. So with these three principles and tools, we can measure and determine which organism in the food web is more important. (I will be talking more about the Food Web in my next post) With that, I end my post. Link One Glossary Biology The science that involves studying living organisms. Geology The science that involves the history of the Earth. Chemistry The science that involves studying the propeties of organisms. Acidification The process whereby something becomes more acidic. Principle A common rule or standard is accepted and used. |
By Zhan Peng from 2-6 Catholic High School Class 2-6 One Golden Rule NOTHING |