Succession & Geochemical Cycles Unit 2 Notes

Changes Over Time Ecological Succession – natural changes and species replacements in communities of an ecosystem Occurs in stages as different species create conditions suitable for some species and unsuitable for others Often difficult to observe – can take decades This Slide deck coincides with the Smartboard titled, “6.3 Ecological Succession” Reading H – 20.2 p.408-410, 21.1 p. 417-422, 21.2 p. 423-428 CP – 4.1 p. 79-84 Concepts: Primary/secondary succession Pioneer species Climax community

In the beginning… New land can be created or exposed where no life existed before Lava destroying all life in its path and forms new land An avalanche exposes new areas and ledges A city street has never before had life growing from it. New communities of organisms colonizing these areas is called Primary Succession The first species in the area are called Pioneer Species Example: Lichens (can grow without soil on rocks and other surfaces)

And then… Pioneer organisms die and become the first patches of soil The presence of soil allows weedy plants to emerge, and over time vines, shrubs, and trees appear When this primary succession slows down and the community becomes stable This mature community undergoing little or no change is called the Climax Community.

From Pioneer Species to Climax Community

Disaster Strikes… When natural disaster or human actions disrupt or destroy a community, the following community changes are called Secondary Succession Like Primary Succession, the communities of organisms gradually change Unlike Primary Succession, this occurs where there was once life and on land that contains soil

Secondary Succession Because there is soil Pioneer Species will be different from the Primary Succession Example: Lichens were pioneers in Primary where wildflowers may be pioneers in Secondary Secondary Succession will take less time to reach Climax Community Though Pioneer Species may be different, the Climax Community will most likely be similar if the climate it the same.

Secondary Succession

Geochemical Cycles Geochemical Cycles are the movement of a particular form of matter through the living and nonliving parts of an ecosystem. Since Earth is a closed system, it must continually cycle its essential matter. Energy Flows through an ecosystem and Nutrients cycle in an ecosystem. These slides correspond with the Smartboard lessons titled, “6.4 What are Geochemical Cycles, water, carbon, nitrogen cycles” Reading H – 18.4 p. 371-374 CP – 4.3 p. 90-93 Concepts: The cycles

Geochemical Cycles cont. Matter changes form but is neither created nor destroyed; it is used over and over again in a continuous cycle. Organisms are an important part of this cycling system. Matter placed into biological systems is always transferred and transformed. Matter, including carbon, nitrogen, and water, gets cycled in and out of ecosystems. These slides correspond with the Smartboard lessons titled, “6.4 What are Geochemical Cycles, water, carbon, nitrogen cycles” Reading H – 18.4 p. 371-374 CP – 4.3 p. 90-93 Concepts: The cycles

Water Cycle Water is a necessary substance for the life processes of all living organisms. Water is found in the atmosphere, on the surface of Earth and underground, and in living organisms.

Water Cycle The water cycle, also called the hydrologic cycle, is driven by the Sun’s heat energy, which causes water to evaporate from water reservoirs (the ocean, lakes, ponds, rivers), condense into clouds, and then precipitate back to water bodies on Earth. Organisms also play a role in recycling water from one form to another by: Intake of water into the organisms Transpiration Respiration Elimination

Carbon Cycle Carbon is one of the major components of the biochemical compounds of living organisms (proteins, carbohydrates, lipids, nucleic acids). Carbon is found in the atmosphere and also in many minerals and rocks, fossil fuels (natural gas, petroleum, and coal) and in the organic materials that compose soil and aquatic sediments. Organisms play a major role in recycling carbon from one form to another in the following processes: Photosynthesis Respiration Decomposition Conversion of biochemical compounds

Carbon Recycling Processes Photosynthesis: Autotrophs take in carbon dioxide from the atmosphere and convert it to simple sugars. Respiration: Organisms break down glucose and carbon is released into the atmosphere as carbon dioxide.

Nitrogen Cycle Nitrogen is the critical component of amino acids which are needed to build proteins in organisms. Nitrogen is found in the atmosphere as elemental nitrogen (N2), in living organisms (in the form of proteins and nucleic acids), or in organic materials that compose soil and aquatic sediments. Organisms play a major role in recycling nitrogen from one form to another in the following processes: Nitrogen-fixation Intake of nitrogen into the organisms Decomposition Denitrification

Nitrogen Recycling Processes Nitrogen-fixation: Nitrogen-fixing bacteria, which are found in the soil, root nodules of plants, or aquatic ecosystems, are capable of converting nitrogen found in the air or dissolved in water into the forms that are available for use by plants. Intake of nitrogen into the organisms: Plants take in the nitrogen through their root systems in the form of ammonia or nitrate and in this way, nitrogen can enter the food chain.

Nitrogen Recycling Processes Decomposition: When an organism dies or from animal waste products, decomposers return nitrogen to the soil. Denitrification: Bacteria change nitrates into gaseous nitrogen

Ecosystem Maintenance and Human Impacts Unit 2 Notes

Maintaining Ecosystems All of the Earth’s processes help ecosystems maintain our biosphere Our biosphere is the inhabited portion of our planet made up of three parts: Atmosphere Hydrosphere Geosphere Each of these systems must interact efficiently for each ecosystem to be maintained These slides coincide with the Smartboard titled, “02 Bio 6.5 Ecosystem Maintenance” H – 22.1 p.435-439 CP – 6.1 p. 125-127, 6.2 p.128-129 Concepts: Ozone layer Greenhouse effect Sink Geosphere: soil erosion, deposition

Atmosphere Our atmosphere is primarily composed of materials from life’s processes. Oxygen Plants and other autotrophs produce enough oxygen for themselves and other organisms through photosynthesis The oxygen from photosynthesis is also responsible for the ozone layer which prevents the sun’s UV radiation from reaching the Earth’s surface Carbon Dioxide Animals release carbon dioxide into the atmosphere that is used by Plants in photosynthesis. The processes of photosynthesis and cellular respiration help keep the concentrations of oxygen and carbon dioxide balanced.

Atmosphere Nitrogen Water Carbon Nitrogen in the atmosphere is maintained by the Nitrogen cycle Water Water vapor in the atmosphere is maintained by the water cycle Carbon May enter the atmosphere thorough the burning of fossil fuels, burning trees/forest fires, cellular respiration, and decomposition/decay of organic matter.

Hydrosphere The hydrologic cycle is maintained by the energy of the Sun and the effect of weather. The hydrologic cycle purifies water in several ways: Evaporated water is pure water containing no impurities. As water seeps down through the soil and rock it is physically filtered of impurities. As water flow slows, heavier particles of sediment settle out, leaving purified water to travel toward the oceans.

Geosphere As part of the geosphere, the soils on Earth are constantly being generated and eroded. All soils are composed of four distinct components – inorganic minerals, organic matter, water, and air. Erosion of rocks and the presence of soil in an ecosystem allows for succession to take place.

Atmosphere Imbalance The greenhouse effect is the normal warming effect when gases (such as carbon dioxide, oxygen, methane, and water vapor) trap heat in the atmosphere. The amount of carbon dioxide in the atmosphere cycles in response to how many plants and other photosynthetic organisms cover Earth and how much carbon dioxide they absorb. The amount of carbon dioxide in the atmosphere also cycles in response to the degree to which oceans cover Earth. The salt water of oceans acts as a sink for carbon dioxide, absorbing what plants do not use and converting it to various salts such as calcium carbonate.

Human Activities vs. Earth’s Processes Human populations have a carrying capacity as well. To have a sustainable population, there needs to be a balance between the Earth’s resources, the needs of humans, and the needs of other species on Earth. Factors that affect human population sustainability are: Population growth Technology Agricultural Industrial Alternative Energy Building Roads and Bridges Resource Consumption

Population Population growth world-wide has grown exponentially and is expected to continue to do so. Population growth will naturally slow down as it nears its carrying capacity due to an increase in the death rate and a decrease in the birth rate as a result of: Food and water shortages Pollution of the environment Spread of diseases An increasing population can have an effect on: the amount of available clean water the amount of waste that is produced the amount of available fertile soil for agriculture (food resources). Impacting animal habitats and migratory routes Bill Nye-Human Impact on Biodiversity

Technology Technology applies scientific knowledge to help meet the needs of humans. These technological advances in agriculture, industry, and energy can have a positive or negative impact on Earth. Agricultural technology - Positive: Improved Technology More Food Produced - Negatives: Pollution Less Diversity in Crops Consumes Energy

Industrial Technology Advances in industrial technology have changed the world and have lead to developments in communication, transportation, and industry. The development of certain chemicals have contributed to the depletion of the ozone layer, which results in increased ultraviolet rays reaching Earth. Technological advances have revolutionized the communication industry; however, the disposal of outdated or damaged equipment is becoming an increasing concern. The burning of fossil fuels for industry and transportation: increases the greenhouse gases produces acid rain Carbon Footprint

Technology Alternative energy technology Using natural renewable energy sources (such as wind, water, geothermal, or solar energy) decreases the burning of fossil fuels, which increases the quality of the atmosphere and the cycles involved. Using nuclear energy technology provides an alternative energy source that does not impact the atmosphere. However, the waste produced from nuclear energy use is becoming an increasing concern.

Resource Consumption As the population increases and technology expands, the demand for Earth’s limited supply of resources also increases. Some resources (such as food, clean water, and timber) are considered renewable resources, those that can be produced at roughly the same rate that they are consumed.

Resource Consumption Other resources, such as fossil fuels, are nonrenewable resources, those that cannot be produced at the same rate that they are consumed. For example, Sustainable use of resources can be accomplished by reducing consumption, reusing products rather than disposing of them, or recycling waste to protect the environment.