WEEK 1Today I constructed my mesocosm and watered it for the first and only time, as if the experiment is successful, the plants should be able to survive off recycled oxygen, water and nutrients. I poured in enough water to make the bottom layer of pebbles wet, as according to my research, this is a good indicator of how much water the mesocosm needs. I made sure not to add too much water, as this will rapidly increase the humidity of the mesocosm, causing the plants to rot. I have placed my terrarium in a sunny place, although without harsh direct sunlight, as this will cause the leaves to burn.
There are just 3 species in my mesocosm: native violets, baby ferns and moss. I anticipate that the plants will survive with one another as there should be adequate space for them to grow in the jar. The bacteria in the soil from the stream water should also help them grow. For quantitative data, I will be measuring temperature, humidity, the diameter of the moss (as I predict that it will spread) and condensation. The initial temperature is 20.6 degrees Celsius, whilst the humidity is at 39%. The diameter of the moss is 5cm. On a scale of 1 - 10, the condensation level is at 0, as the mesocosm, has not yet had time to develop more humid conditions. I expect to see some condensation after a week. WEEK 2Temperature: 22.1 degrees Celcius
The temperature has risen by 0.5 degrees, which is not a very significant increase, considering it has been in the sun all week. Since a couple of the leaves of the fern turned brown, so I decided to move my mesocosm into a cooler area with dappled sunlight. Humidity: 52% This is a significant 13% increase from last week. The rise in humidity has occurred due to the very warm conditions of the area I placed it in. Also, I may have added too much water to the soil last week, causing too much moisture within the jar. Hopefully the humidity will reduce in a cooler area. Condensation: 4 The condensation relates to the rise in humidity. There are visible water droplets inside the glass, however there doesn't appear to be a major excess of water. This indicates that the pebbles are successfully acting as drainage. Moss diameter: 7cm Despite no significant growth in height of the ferns or the violets, the mesocosm has facilitated growth as the diameter of the moss has increased by 2cm. WEEK 3Temperature: 23.4 degrees Celcius
Since last week, the temperature has increased by 1.3 degrees. This was an unexpected result, as I placed my mesocosm in a cooler area. The plants are absorbing heat from sunlight through photosynthesis. Humidity: 48% There is a 4% decrease in humidity, most likely due to the cooler position of the jar. There is no evident correlation between humidity and temperature, although both have remained relatively stable over the past week. Condensation: 6 The photo to the left does not effectively demonstrate the level of condensation on the jar, however there is a significant difference to last week. Despite the decrease in humidity, there is more condensation, so I think this is due to too much water at the beginning of the process. Moss diameter: 7.3 cm The moss has increased in diameter by 0.3cm, therefore conditions still allow plants to grow. However, it appears that the fern is dead as there has been no evident growth, and most of the leaves are brown. Also, the plants are now leaning against the walls of the jar, indicating that the jar is too small and they do not have enough room to grow. The native violets are beginning to dominate the mesocosm. It is possible that the violets have restricted the growth of the fern, again due to the size of the jar. WEEK 4Temperature: 24 degrees Celcius
The temperature of my mesocosm has steadily risen over the past four weeks. This is because it continues to absorb heat yet the heat has no place to escape to. Humidity: 51% The humidity has risen, although not by a significant amount. However, there is a substantial amount of water at the bottom of the jar. This means there is too much water within the mesocosm. Condensation: 7 There is a noticeable amount of condensation, to the extent that it has become difficult to see through the glass. Moss diameter: 7.8 There is a significant growth of both the moss and the native violet. Almost the entire surface area of the soil is now covered with greenery. |