Our Plant's Role in Biogeochemical Cycles

This week, we noticed that our plant was consistently growing both in height and in width. There were a few bites taken out of our Brassica oleracea plant, and it is growing wider as well. The leaves are growing larger, and fanning outwards. Our plant has a total of nine leaves as of today, two more leaves than it last had about 2 ½ weeks ago. Our cabbage plant is taking up more room in the plant area, and spreading out its roots.

In the biosphere, plants play a large role in the water cycle, much like our cabbage plant. As water precipitates, or falls from the sky as rain, it is absorbed and taken into the soil. After the water is absorbed in the soil, the plant’s roots take the water into its stem and leaves for purposes such as photosynthesis, to make food, and cellular respiration, where the plant releases the water back to the atmosphere. Throughout this week, our plant has used the water cycle through photosynthesis, where the plant takes sunlight, water, and carbon dioxide and makes glucose for food. Our plant also transpired, or released the water through the leaves that it had taken in through the roots.

In the biosphere, our plants are taking in carbon dioxide and releasing oxygen, participating in the movement of carbon. The plant’s role in the carbon cycle is shown through photosynthesis and respiration as well. When humans take in oxygen from the air, they breathe out carbon dioxide. Plants are the opposite, when they take in carbon dioxide during photosynthesis, they release oxygen during respiration. Without the food produced by our plant, it never would have grown. `

Our plant’s role in the nitrogen cycle is to take in nitrogen but also put it back into the soil. When a plant is in the ground, its roots take in this nitrogen from the soil. However, without nitrogen fixing bacteria, it is not possible. The plant is then able to place the nitrogen back into the soil from its roots if not needed. Another way that plants put nitrogen back into the soil is through death and fossilization. When a plant or any organism dies, its remains sit on the ground and are decomposed by fungi and bacteria. As the body is broken down, nitrogen is released into the soil. Also, when an organism becomes fossilized, as its carcass is buried deeper in the earth, nitrogen becomes more present.