Ecosystems and Energy Lecture 4 Flashcards
What is ecology?
study of interactions among and between organisms in their abiotic environment
What is biotic?
living environment (includes all organisms)
What is abiotic?
non-living or physical environment
What are ecologists interested in?
levels of life above the organism-level
What is a species?
group of similar organisms who breed and make offspring
What is a population?
group the same species living in the same area
What is a community?
populations of different species that live in the same area
What is an ecosystem?
a community and its abiotic environment
What is a landscape?
several interacting ecosystems
What does the biosphere contain?
earth’s communities, ecosystems, and landscapes
Where is the biosphere?
lies within and derives energy and elements from the atmosphere, hydrosphere, and lithosphere
What is energy
ability or capacity to do work
What are the types of energy?
chemical, thermal, mechanical, nuclear, electrical, radiant, solar
What is chemical energy?
energy is stored in the bonds of molecules
What is thermal energy?
heat that flows from an object with a higher temp to an object with a lower temp
What is mechanical energy?
energy in the movement of matter
What is nuclear energy?
energy stored in atomic nuclei
What is electrical energy?
energy that flows as charged particles
What is radiant energy?
energy transmitted as electromagnetic waves
What is solar energy?
radiant energy from the sun
What is the primary energy source on earth?
solar radiation
What do plants do with solar radiation?
turn it into chemical energy
What is potential energy?
stored energy
What is kinetic energy?
energy of motion
What is thermodynamics?
study of energy and its transformations
What is a closed system (rare in nature)?
energy is not exchanged between a closed system and its surroundings
What is an open system (common in nature)?
energy is exchanged between an open system and its surroundings
What is the first law of thermodynamics?
energy cannot be created or destroyed; it can only change from one form to another
What is the second law of thermodynamics?
when energy is converted from on form to another, some of it is degraded to heat (heat is highly disorganized)
How does the 1st law of thermodynamics apply to ecology?
organisms cannot create energy for life, they must instead capture energy from the environment to do biological work
How does the 2nd law of thermodynamics apply to ecology?
when organisms capture energy from the environment, most of the energy is dispersed as heat
What is photosynthesis?
energy from the sun (radiant energy) is transformed into chemical energy of carbohydrate (sugar) molecules
What is cellular respiration?
chemical energy is released within cells of plants and animals that is then used for biological work
What are ecological pyramids?
graphically represent the relative energy value of each trophic level
What are the three main types of ecological pyramids?
pyramid of…. numbers, biomass, and energy
What is a pyramid of numbers?
illustrates the number of organisms at each tropic level
What doesn’t the pyramid of numbers indicate?
biomass of organisms at each level and amount of energy transferred between levels
What is a pyramid of biomass?
illustrates the total biomass at each successive trophic level
What is biomass?
measure of the total amount of living material
How much reduction of biomass is there through trophic levels?
90% reduction (100 to 10)
What is a pyramid of energy?
illustrates how each energy is present at each trophic level and how much is transferred to the next level
What is Gross Primary Productivity (GPP) - producers?
total amount of energy that plants capture as sugars over a period of time
What is cellular respiration (CR)-producers?
Sugars are metabolized by plant to provide energy
for plant work
What is Net Primary Productivity (NPP)-producers?
Plant growth per unit area per time (Only NPP is available as food to organisms)
What is Gross Primary Productivity (GPP)- ecosystems?
Total amount of energy that autotrophs within an
ecosystem capture
What is Ecosystem Respiration (ER)- ecosystems?
Energy loss from metabolism of both autotrophs and
heterotrophs in an ecosystem
What is Net Ecosystem Productivity (NEP)?
NEP= GPP-ER
What happens in the global carbon cycle?
- 50% of GPP is used for plant cellular respiration and the rest goes into new growth (NPP)
- 80% of annual NPP is returned to the atmosphere by ecosystem respirations
What is net ecosystem production (NEP)?
remainder of biomass that builds up on the site after all these losses have been subtracted
What is left after fire an other disturbances?
net biome production (NBP)
What do humans consume a lot of?
global NPP (consumption is 30% but we only make up .5% of biomass)
