Population Interactions Decomposers are organisms that recycle materials back into the environment. These materials can then be reused by producers. Scavengers are consumers that eat dead organisms Parasites are organisms that attack other live organisms but rarely kill them.

Population Interactions Normally, each organism feeds on more than one kind of organism. Because organisms have more than one food source, food webs are used to show the more complex feeding relationships between producers, consumers and decomposers.

Energy Flow Through an Ecosystem Almost all organisms use solar energy stored in food to power their life processes. That energy is continuously lost due to daily activity. As a result each step in the food chain has less energy than the original solar energy available to it.

Energy Flow Through an Ecosystem An energy pyramid is a diagram that illustrates the transfer of energy through a food chain or web. Each block of the energy pyramid represents the amount of energy received from the organism below it. Producers are the first block because they can utilize the sun’s energy.

Energy Flow Through an Ecosystem Decomposers like bacteria and fungi extract the last bits of energy in dead organisms. As they do so, they return the raw materials of the dead organisms to the soil. Much of the cycling of materials such as carbon, hydrogen, oxygen and nitrogen is done by decomposers.

Diversity Benefits Species & Habitats. Biodiversity is the measurement of the degree to which species vary within an ecosystem. The more diverse an ecosystem is the more stability it has. Diversity in the ecosystem can provide humans with medicines and other useful resources. As we destroy these ecosystems, valuable resources are lost with it.

Environmental Changes Fires, earthquakes tornadoes and other natural disasters can often destroy an entire ecosystem. When this happens a series of slow changes will occur in an area until a stable community is reached These slow changes toward stability are called succession.

Human Impact on the Ecosystem The Earth’s temperature is rising, this temperature change is upsetting the natural balance, ice in the arctic is melting, coral reefs are dying – this is a global problem. CO2 emissions from factories and cars around the world are responsible for the greenhouse effect.

Global Warming The "greenhouse effect" is the heating of the Earth due to the presence of greenhouse gases. It is named this way because of a similar effect produced by the glass panes of a greenhouse. Shorter-wavelength solar radiation from the sun passes through Earth's atmosphere, then is absorbed by the surface of the Earth, causing it to warm.

Global Warming

We’re already seeing changes: Glaciers are melting, plants and animals are being forced from their habitat, and the number of severe storms and droughts is increasing. The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years. Malaria has spread to higher altitudes in places like the Colombian Andes, 7,000 feet above sea level. The flow of ice from glaciers in Greenland has more than doubled over the past decade. At least 279 species of plants and animals are already responding to global warming, moving closer to the poles.

Global Warming If the warming continues, we can expect catastrophic consequences: Deaths from global warming will double in just 25 years -- to 300,000 people a year. Global sea levels could rise by more than 20 feet with the loss of shelf ice in Greenland and Antarctica, devastating coastal areas worldwide. Heat waves will be more frequent and more intense. Droughts and wildfires will occur more often. The Arctic Ocean could be ice free in summer by More than a million species worldwide could be driven to extinction by

Global Warming

Human Impact on the Ecosystem A renewable resource can be replaced within a generation. Solar energy, water and wind are renewable resources. A nonrenewable resource is limited and cannot be replaced. Energy sources such as coal, oil an natural gas as well as metals such as gold, silver, iron and copper are nonrenewable resources.

Human Impact on the Ecosystem Solar energy We can use the energy in sunshine to warm and light our homes, heat our water, and provide electricity to power our lights, stoves, refrigerators, and other appliances. This energy comes from processes called passive solar heating, solar water heating, and photovoltaic energy (converting sunlight directly into electricity).

Human Impact on the Ecosystem Wind Energy For centuries, the wind has been used to sail ships, grind grain, and pump water. Now, people use the wind to generate electricity. Wind energy is a clean alternative to fossil fuels.

Human Impact on the Ecosystem Geothermal energy We can also get energy directly from the heat in the earth. Geothermal energy starts with hot, molten rock (called magma) miles below the earth's surface that heats a section of the earth's crust. The heat rising from the magma warms underground pools of water. Sometimes the water can even boil to produce steam.

Human Impact on the Ecosystem Biomass energy Because plants and trees depend on sunlight to grow, biomass energy is a form of stored solar energy. Although wood is the largest source of biomass energy, we also use corn, sugarcane wastes, and other farming byproducts.