Jar Mass
In my biology Grad standard, I found that the mass of my terrarium jar gradually decreased over time. The conservation of mass law states that “the total mass of substances does not change during a chemical reaction”. In addition, the organisms had to recycle all of their own matter in order to survive; the fungi had to eat plant waste, the bacteria had to eat fungi, and the grass had to survive off of both of them to make a semi-functioning life cycle within a jar. Also, the vital cycles must be kept intact in order to allow the plants to survive as long as they did.
Although at the writing of this paper I do not have the petri plate I made of the organisms, I did find a rather helpful Internet source on the subject. Firstly, fungi. Fungi are supposedly found near the surface of the soil where there is more oxygen and a good supply of organic material, most likely from dying grass. I think that the fungi reached it’s peak in my jar towards the end of the experiment, due to what I feel must have been a rather sizable amount of decaying matter. Another prominent group of living things in my jar must have been bacteria. In a healthy soil their numbers could exceed 10 to the 9 or one thousand billion per gram of soil with over 20,000 species present, which means that in my soil it was probably about nine hundred billion per gram of soil. Bacteria take part in almost all soil decomposition reactions and are crucial to the breakdown of soil organic matter. Also, the cyanobacteria are responsible for fixing the nitrogen cycle. Also, I had some grass in there that may have played a small role in the CO2-02 cycle (well, actually they altered the environment and internal atmosphere to a great extent, but I would rather look at interactions of the big and small). In summary, my jar contained Fungi, Prokaryotae, and Plantae.
To understand the lifespan and changes in mass it is important to understand how the life cycles work within the community. Firstly, the water cycle. Water is taken in by the grass which use it and other chemicals in order to photosynthesize. Water also evaporates in the jar and then condenses on the walls of the jar. The carbon cycle is a complex series of processes through which all of the carbon atoms in existence rotate. Plants, animals, and soil interact to make up the basic cycles of nature. In the carbon cycle, plants absorb carbon dioxide from the atmosphere and use it, combined with water they get from the soil, to make the substances they need for growth. The process of photosynthesis incorporates the carbon atoms from carbon dioxide into sugars. Animals, such as the rabbit, eat the plants and use the carbon to build their own tissues. In this instance, the rabbit would be replaced by the bacteria and the fungi.
Though I am not sure exactly what went on in my jar, I do have some good guesses. I think that several fungi and bacteria preyed on the grass and that the bacteria ate, or at least interacted with, the fungi. The various forms of bacteria interacted with everything, and even for their size, they had even more of an effect on everything as stated above.