How does the Sun support life?
- Lights and Warms the Planet
- Powers the Cycling of Matter
- Drives Climate and Weather-Causes the uneven heating of air and water that drives the distribution of those things around our Planet.
- Enters the Living System through Producers and Photosynthesis
ENERGY VS MATTER
- The energy from the sun is constantly moving through the Earth system, but it is not recycled.
- First Law of Thermodynamics: Energy cannot be created or destroyed. So energy input is always equal to energy output.
- Second Law of Thermodynamics: As the energy goes through a system the quality of that energy will decrease (entropy.) Most energy is converted to heat as it passes through the system.
- The nutrients and the rest of the matter that are here on Earth is constantly being recycled and rarely ever leave the Earth system.
Gross vs Net Primary Productivity
Gross Primary Productivity is the total amount of energy (sugars) created by the producers through photosynthesis in a biome. Compare this to the paycheck you receive with all of the money you earned.
Net Primary Productivity is the amount of energy (sugars) left over for the rest of the biome to consume after the plants have respired and consumed some of what they created. Compare this to the money you have left after taxes have been taken out.
Sea Otters are a famous example of a keystone species. Oyster harvesters in the Pacific thought that the Otters were competing with them for the oysters, so they shot them whenever they saw them. The Harvesters did not realize that the Otters also kept the Kelp that grew on the ocean floor maintained where the oyster habitats were. When the Otters became ecologically extinct, the entire ecosystem collapsed. The otters have since started to recover. Keystone species in general have a substantial effect on the ecosystem through the services they provide and the interactions with other organisms.
Other Keystone species include:
Endangered, Threatened, Extinct
- Threatened species are abundant in its natural range, but numbers are declining.
- Endangered species have so few survivors it can experience ecological/biological extinction.
- The United States Fish and Wildlife Service (USFWS) and the National Office for Atmospheric Administration (NOAA) are the two agencies responsible for identifying and regulating the Endangered Species Act.
There are four types of extinction:
- Ecological Extinction: There are not enough left to provide the ecological services they would normally add to an ecosystem.
- Commercial Extinction: There are not enough left to harvest for profit. (Fish usually)
- Local Extinction: No longer found in an area.
- Biological Extinction: No longer exists on this planet.