Ap Biology Ecology Essays free essay sample

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 colonize the surroundings. Once these mosses establish themselves, soil starts to gradually develop as rocks weather and organic matter accumulates from decomposed remains of early colonizers. Now that soil is present, the mosses will soon find themselves overgrown by grasses, shrubs, and trees that are either blown in by wind or carried in by other animals. Eventually, an area is colonized by plants that become the community’s prevalent form of vegetation. The other type of ecological succession is called secondary succession. Unlike primary succession, secondary succession occurs when an existing community is cleared due to some significant disturbance that leaves soil intact. In some cases, the disturbed area is able to return back to its original state. An example of this could take place in a forested area cleared for farming and later abandoned. In this case, the earliest plants to start colonization are often herbaceous species that grow from windblown or animal-borne seeds. In the case that the area has not been burned or heavily grazed, woody shrubs may in time replace most of the herbaceous species, which would soon be followed by forest trees. While both kinds of ecological successions have their own unique characteristics and steps, there are some factors both have in common. Both kinds of succession feature factors that can be arranged in a pyramid of biomass. In primary and secondary succession, there we large masses of plants present that could support a medium mass of herbivores and a small mass of carnivores. Also note that in both types of successions, the amount of energy incorporated into the next trophic level from the previous only included a relatively small amount of energy, which accounts for 10%. . Competitive Exclusion (Gause’s Principle): Competitive exclusion is the concept that when populations of two similar species compete for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other population. This concept was first observed by Russian ecologist G. F. Gause, whom the concept was named after. In his observation, he studied the behavior of paramecium aurelia and paramecium caudatum. During the duration of the experiment, in which both were under stable condition and received an equal amount of food each day, each population grew rapidly and the leveled off at what was apparently the carrying capacity. Once put together, however, the paramecium caudatum became extinct. From this, Gause inferred that the paramecium aurelia held a competitive advantage in obtaining food and concluded that both cannot coexist in the same environment. Ecological Succession: Ecological succession is the transition in the species composition of a community following a disturbance in the ecosystem. An example of this can be observed over time on a newly formed volcanic island by primary succession. The first forms of life are initially autotrophic and heterotrophic prokaryotes. They are then followed by mosses grown from windblown spores. Soil starts to develop gradually as rocks weather and organic matter accumulates from the decomposed remains of the early colonizers. Now that the soil is present on the island, the mosses are now overgrown by grasses, shrubs, and tress that sprout from seeds blown in from nearby areas or carried in by animals. Eventually, the area is colonized by plants that become the prevalent form of vegetation in the community. Such a process may take hundreds or thousands of years to develop. Nutrient (Biogeochemical) Cycles: Biogeochemical cycles are the circulation pathways of elements (carbon, oxygen, hydrogen, nitrogen, or mineral elements) through the biotic and abiotic components of an ecosystem. One often mentioned biogeochemical cycle in biology is the carbon cycle. This cycle demonstrates how terrestrial and aquatic organisms exchange carbon dioxide with the atmosphere. Photosynthesis removes carbon dioxide from the atmosphere, while respiration and combustion add it. When neither photosynthesis or respiration is taking place, the carbon dioxide from the air combines with water to produce bicarbonate, a source for aquatic producers like algae. When aquatic organisms respire, the carbon dioxide released combines with water to form bicarbonate. As mentioned earlier, it should be noted that during this cycle, the amount of bicarbonate is almost always in equilibrium with the amount of carbon dioxide in the air.