Module #5 - Biogeochemical Cycles and World Biomes

The World's Biomes

4. Complete Quiz #2: Biogeochemical Cycles (under Assessment and Quiz #2) between 11:15 - 11:45 am TODAY (Thurs. March 3rd) and submit to Mr. Durk on the D2L.

GOOD LUCK!

ecosystems are one way of subdividing the earth into systems that have unique characteristics, for example: landforms, climate, vegetation, and soils. These characteristics or components of ecosystems are shaped by processes that involve the flow of matter and energy through the ecosystem. These flows, or cycles, include the hydrologic cycle and nutrient cycles, such as the carbon cycle and the nitrogen cycle. These are the three primary cycles that we observe in nature, however, you are also responsible for understanding the basics of the phosphorous and oxygen cycles as well.

The hydrologic cycle, or water cycle, is the circulation, or flow of water between the atmosphere and the earth’s surface. The water cycle is responsible for large amounts of energy, creating worldwide movements of water. Precipitation that falls to the earth, in the form of snow or rain, drains back to the oceans by river systems or groundwater. These huge flows of water and energy form and change the landforms and climate patterns within ecosystems and ecozones. The amounts and types of vegetation and soil depends directly on the water cycle. The human and animal populations of a region rely on the availability of water. Humans alter the flow of water through use and over-use of freshwater supplies, and through the pollution of air and water.

Hydrologic Cycle

Credit: Physicalgeography Net

The Carbon cycle is the movement of carbon and its compounds between the earth, oceans, atmosphere, and organisms. Carbon is an essential nutrient for living things. It exists in rocks, the atmosphere, and the oceans. Carbon flows through ecosystems by the process of photosynthesis, where carbon dioxide is converted to green matter, and by the reverse flow, where living creatures convert oxygen and sugars into carbon dioxide and water through the process of respiration. Humans alter the flow of carbon by depleting the earth’s forests, and through the burning of fossil fuels.

Carbon Cycle

Credit: Physicalgeography Net

The nitrogen cycle is the movement of nitrogen between the atmosphere, organisms, and the earth. Nitrogen is an essential nutrient for plant growth, but to be used by plants it first needs to be converted into nitrates in the soil.

Humans alter the flow of nitrogen by adding fertilizer to soil, and through the burning of fossil fuels. This change or increase in the amount of nitrogen in the atmosphere contributes to air pollution and acid rain.

Nitrogen Cycle

Credit: Physicalgeography Net

When significant changes occur in the flow of matter and energy through ecosystems, the components change. Some landforms and soils weather or wear away; some plants and animals die; climates change; humans relocate to other areas. Some changes occur naturally over time, others have impacts that are increased because of the effects humans have on their environment.