Ap Biology Ecology Essays

1. Living organisms play an important role in the recycling of many elements within an ecosystem. One such way this idea can be proven is through the study of carbon in an ecosystem. Plants, for starters, are a major part of this carbon cycle. During photosynthesis, plants remove carbon dioxide from the atmosphere and release oxygen as a waste product. Another major contributor to this vital cycle is the human being. The average human being goes through respiration each day to help maintain homeostasis. Unlike photosynthesis, carbon is the waste product in respiration, while oxygen is removed from the atmosphere. If carbon isn’t cycling through either photosynthesis or respiration, it reacts with water, in the form of carbon dioxide, to produce bicarbonate. The bicarbonate is a source of energy for aquatic producers such as algae and other aquatic vegetation. On similar terms to the formation of bicarbonate, when aquatic organisms respire, the carbon dioxide released from them in turn reacts with water to form bicarbonate. Human activity has also made a huge impact in this cycle. As humans continue to use fossil fuels daily, the amount of carbon dioxide in the air increases. Lastly, one must remember that the amount of bicarbonate in the water is in equilibrium with the amount of carbon dioxide in the air in the carbon cycle.
2. Ecological succession is the transition in the species composition of a community following a disturbance in the ecosystem. This process can occur either as primary or secondary succession. In primary succession, the process begins in a virtually lifeless area where soil has not yet formed, such as on a newly formed volcanic island or on the rubble of a retreating glacier. Most of the time, the only life-forms present in the early stages of primary succession consist of autotrophic and heterotrophic prokaryotes. Mosses, which come from windblown spores, soon follow and are the area’s first macroscopic photosynthesizers to