mesocosm

Name: Aakanksha seelam Grade: 12 Date of the experiment: 18/08/2015 Introduction: Aquatic mesocosms are experimental water enclosures which are designed to provide a limited body of water within a closed natural environment. The mesocosms experiment is often considered to be the experimental ecosystem which is closest to the real world. Thus mesocosm studies have the advantage compared to laboratory approaches that it maintains a natural community under close to natural conditions, taking into account relevant aspects from ‘the real world’ such as indirect effects, biological compensation and recovery, and ecosystem resilience. By integrating over multiple direct and indirect species effects up or down the food web, the responses obtained from mesocosm studies can be used for parameterization in ecosystem and biogeochemical models. Mesocosms have been present in experimental ecology since the early 20th century, however have only been regarded as significant research tools - especially concerning climate change - since about 1995. Mesocosms is a simple representation of complex biological natural systems in a controlled environment. This helps the scientists to predict the natural occurrences when there is a change in the environmental factors. The nutrients formed in the biochemical cycles in closed systems are neither created nor lost. However the nutrients are continually recycled and reused with in the closed ecosystem.

Advantages: The advantage to mesocosm studies provides us with what we already know and provides us with possible influential factors will produce positive or negative reaction if our subject areas of interest. Manipulating something can give us an idea as to expect if something were to occur in that ecosystem of environment. Disadvantages: Greenhouse contributes to mesocosm studies although sometimes, it may induce climate change interfering with the experiment and resulting in inefficient data. Using growth chambers for a laboratory experiment us sometimes a disadvantage due to limited amount of space. Another disadvantage in using mesocosm is not adequately imitating the environment, causing the organism to avoid giving off certain reaction versus its natural behavior in its original environment.

Materials required: 1. Conical flask 2. Hydra plant 3. soil 4. aquarium water 5. cotton(plug) 6. Aluminum foil.

Variables: Controlled variables: Room temperature. Volume of water remained constant throughout the experiment. Same plant i.e Fern was used in all the test groups.

Procedure: 1. 2. 3. 4. 5.

Take a conical flask. Create an artificial pond ecosystem by adding mud, stones of different sizes. Add aquarium water in the conical flask. Close the conical flask with cotton so that there is no exchange of gases. Observe the conical flask for two days.

Precautions: 1. Care should be taken while inserting the plant. 2. Use a narrow mouthed conical flask. 3. Use gloves while inserting the mud into the conical flask. 4. The conical flask should be closed properly so that there is exchange of gas molecules.

Conclusion: It was observed that there is formation of fungi on the top of the water. There is a layer of this fungi forming. The plant also reached the declining stage where the leaves are observed to be rotten and there is formation of bubbles on the walls of the conical flask. This shows that the plant is respiring. The plant reached the declining stage showing that it requires oxygen also to survive. Improvements: The experiment can be improved by using a bigger conical flask. Using pond water can also be used to improve the experiment and obtain better results. A fish can be used later on to confirm the experiment. Pebbles can be used to see the formation of zooplankton. Hydrilla can be used instead a fern and using this can improvise the experiment. You can place the plant in a chamber and manipulate the light, temperature and heat distribution. These can be changed and the activity of the plant can be compared by changing the different factors