Lecture 27: Ecosystem Ecology

What is an ecosystem?

all individuals of all species in a specified area plus abiotic factors

What is ecosystem ecology?

examines how the biotic and abiotic components of the ecosystem interacts

What is the first law of thermodynamics?

energy cannot be created or destroyed; it can only be transformed or transferred. This law occurs in the food chain as it energy is transformed into sunlight to chemical energy and then are transferred to animal or plant.

What is the second law of thermodynamics?

energy transfers and transformations are not 100% efficient; some energy is lost as heat. This applies through an ecosystem as energy is lost with body functions or in fecal matter

What is trophic efficiency?

only 10% of energy is transferred from one tropic level to the next

How do you calculate production efficiency?

NPP (Net primary production) = GPP (Gross primary production) - Ra (cellular respiration of the autotrophs)

What is the gross primary production?

Total primary production in an ecosystem.

What is the net primary production?

equal to gross primary production minus the energy used by the primary producers for their cellular respiration

Why is trophic efficiency limit the length of food chains and the number and the number of higher level consumers?

since trophic efficiency can only support so little apex predators and food chains can only support 3-5 trophic levels due to the amount of energy it transfers up to the food chain.

What is the water cycle?

Biological Importance: essential to all organisms and many ecosystem processes. Reservoir: 97% is from the ocean, 2% is in rivers, lakes, and ground water, and 1% is shown in polar ice caps and glaciers. Main processes: water across the ocean evaporates from solar radiation and transpiration (evaporation from leaves) occurs —> it turns into water vapor —> condenses into clouds —> when clouds can no longer hold the vapor it condenses —> condenses further and precipitation occurs over land and ocean —> water returns from runoff and groundwater

What is the carbon cycle?

Biological Importance: all organic compounds essential to life contains carbon atoms Reservoir: CO₂ and carbon found in animals Main Processes: photosynthetic organisms and phytoplankton take in CO2(g) into high energy carbon compounds like glucose —> consumers feed directly or indirectly on these photosynthetic organisms gaining chemical energy —> cellular respiration occurs for all animals producing CO2 in their air

What is the Phosphorus Cycle?

Biological Importance: is found in many biologically important molecules such as nucleic acids, phospholipids and ATP. Reservoir: sedimentary rock, soil, ocean, and various organisms Main Processes: weathering of rocks adds phosphate to soil and leeches into ocean —> taken out by producers from ocean and land —> will be eaten by consumers —> returned to water or soil by decomposition

What is Nitrogen Cycle?

Biological Importance: found in amino acids, proteins, and nucleic acids. Limiting plant nutrient Reservoir: the atmosphere Main Processes: nitrogen fixation occurs which turns N2(g) into more usable forms of nitrogen that can be taken in by organisms occurs in volcanic eruption, bacteria, or lightning —> bacteria reverse the nitrate putting it up into the atmosphere called denitrification