Ecosystems Flashcards
What are the 2 major themes in ecosystems?
Energy Flow and Material Cycling
How do autotrophs get their engery?
capture sunlight energy & convert it to chemical bond energy
Most photosynthetic plants and “algae” are consider what functional group?
autotrophs
Autotrophs capture sun’s energy, which runs whole __________
ecosystem
The autotrophs secure _________ for whole ecosystem
nutrients
What is the trophic level for autotrophs?
primary producers
What are the functional groups in a ecosystem?
Autotrophs and Heterotrops
What are heterotrophs?
obtain food from pre-existing organic compounds
What are the sub-groups of heterotrophs
consumers
decomposers:
detritivores:
What are the different types consumers?
herbivores, carnivores, scavengers, parasites
What are decomposers and some examples?
bacteria, fungi (break down dead organisms)
What are detritivores and some examples?
invertebrates that feed on partially decomposed organic matter (e.g., earthworm, crab)
Ecosystems are _________________
open systems
What is a open system?
open systems require constant input of energy
sunlight energy converted to ________________, but some is lost as ________________________
chemical bond energy; metabolic heat (through respiration)
energy flows through ecosystems in one direction, ___________________
through food chains
food chain shows ____________
“who eats whom”
Food chains represents _________
represents energy flow: when an owl eats a lemming, energy is transferred to the owl
What are the trophic levels?
primary producers
primary consumers
secondary consumers
tertiary consumers
What are primary producers?
autotrophs
What are primary consumers?
herbivores
What are secondary consumers?
Carnivores
What are tertiary consumers?
Carnivores
Food chains are ________________________
isolated, simple subunits of complex ecosystems
Food webs are a somewhat _________________________ (although still simplistic)
more realistic representation
there is a ___________ flow of energy in ecosystems
one-way
What are the 2 different food webs?
Grazing and Detrital food webs
What are grazing food webs?
herbivores consume plants, and in turn are eaten by carnivores
What are detrital food webs?
decomposers & detritivores consume most of the system’s energy (not herbivores; most important (e.g. forests)
Consumers use _______ they ingest for their own __________
most energy; maintenance
What is the general rule in ecosystems?
Only about 10% of the energy contained in one trophic level is transferred to the next highest level
Most of the energy in an ecosystem is lost as _______________, and is _______________
metabolic heat (via respiration); unavailable to organisms
Small percentage of energy passed to each successive trophic level results in ____________-
ecological pyramids
_______________ in the base of the pyramid (the producers)
Most energy is contained
Less and less energy at successively __________
higher levels
Productivity of ecosystems affected by __________ and ______________
energy input; availability of nutrients
Plants require ___, _____, and _____, but also ≈___ other minerals (e.g. N, P)
C, H, and O; 13
most nutrients available to plants in ________; e.g. NH4+ (____________) or H2PO4– (____________)
ionized forms; ammonium and phosphorus
These essential elements move in ______________________
biogeochemical cycles
How does the biogeochemical cycle go?
Environment—>organisms—>environment
elements move slowly thru ____________ compared to between __________
physical environment; organisms
What are the two input sources for ecosystems?
environmental inputs
recycling of decomposers/detritivores
What is the hydrologic cycle?
source of hydrogen and oxygen (H2O)
What drives the Hydrologic Cycle?
driven by evaporation (from solar energy) and precipitation
Carbon & other elements cycle through
atmospheric cycles and sedimentary cycles
What is the atmospheric cycles in the Carbon & other elements cycle?
A gaseous phase
What is the sedimentary cycles in the Carbon & other elements cycle?
contained in rocks; cycle between land and sea floor over immense time spans
Carbon moves from ____________ (CO2) & ocean into _________, and back into ____________
reservoirs in atmosphere; organisms; reservoirs
After industrial revolution, new carbon input from burning of _________ and ___________
fossil fuels; deforestation
has ___________ atmospheric concentration of CO2 from ≈280 ppm to ≈392 ppm (2014) to ≈424 ppm (2024), and ______________________
increased; contributes to global warming
