Energy Flow in Ecosystems and Biogeochemical Cycles.
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Transcript of Energy Flow in Ecosystems and Biogeochemical Cycles.
Energy Flow in Ecosystems and Biogeochemical Cycles
Hierarchy of ecology Organism - individual living
thing Population- a group of the
same species Community – a group of
different species Ecosystem Ecosystem – all organisms as
well as nonliving things in an area
Biome - a major regional or global community of organism - can be as small as the microorganisms living on your skin or as large as the entire biosphere
What’s an Ecosystem? An ecosystem consists of all the organisms (biotic)
in a community and the environment (abiotic) with which they interact.
Biotic - living things plants animals, fungi, bacteria
Abiotic - non-living thingsMoisture, temperature, wind, sunlight, & soil
Biodiversity
The assortment, or variety, of living things in an ecosystem
KEYSTONE Species = a species that has an unusually large effect on its ecosystem
ProducerHerbivore
(primary consumer)
Detritivores(decomposers)
Carnivore(secondaryconsumer)
Energy flow
Energy flows THROUGH ecosystems – open system
Chemical cycling
Nutrients cycle WITHIN ecosystems – closed system
Get their energy from non-living sources and make their own food
Get their energy by eating living, or once living, resources, such as plants and animals
Break down organic materials into simpler cpmpounds
Energy Flow in Ecosystems
Almost all energy used in ecosystems comes from the sun
From there it flows through a food chain or web and exits the ecosystem in the form of heat, light, kinetic or chemical energy
A food chain is a sequence that links species by their feeding relation
A food web is a model that shows the complex network of feeding relationships and flow of energy within an ecosystem
Types of Consumers
Herbivores – eat only plants Carnivores – eat only animals Omnivores – eat both plants and animals Detritivores – eat detritis or dead and dying organic matter Decomposers - - detritivores that break down organic matter
into simpler compounds (example : fungi)
Decomposers
Energy pyramids show the efficiency of energy transfer between trophic levels
Generally 10% of energy is transferred Food chains never get beyond 4-5 trophic levels
Carnivores that eat secondary consumers
Carnivores that eat herbivores
Herbivores because they are the first consumer above the producer
The first , or bottom, trophic level
Consumers
Producers
Nutrientsavailable
to producers
Detritivores
Biogeochemical Cycle
Abioticreservoir
Biogeochemical Cycling of Nutrients The movement of a particular chemical through the
biological and geological, or living and non-living parts of an ecosystem.
Most ecosystems require a constant inflow of energy from the sun. In terms of matter, such as oxygen and carbon, the Earth is a closed system and it recycles its resources.
Water cycle Oxygen cycle Carbon cycle Nitrogen cycle Phosphorous cycle
Water Cycle
Solar energy drives the global water cycle – Precipitation– Evaporation– Transpiration
Water cycles between the land, oceans, and atmosphere
Forest destruction and irrigation affect the water cycle
Solar energy
Net movement ofwater vapor by wind
Evaporationfrom ocean
Precipitationover ocean
Evaporation andtranspiration fromland
Transportover land
Precipitationover land
Percolationthroughsoil
Runoff andgroundwater
Carbon Cycle
• Abiotic reservoirs = atmosphere, sedimentary rocks, dissolved carbon in oceans, and fossil fuels– Taken from the atmosphere by
photosynthesis– Used to make organic molecules– Decomposed by detritivores– Returned to the atmosphere by
cellular respiration
Photosynthesis
Burning offossil fuelsand wood
Primaryconsumers
Higher-levelconsumers
Cellularrespiration
Detritus
CO2 in atmosphere
Carbon compoundsin water
Decomposition
Global warming:CO2 lets sunlightthrough but retainsthe heat radiatedfrom Earth.
CO2 in theatmosphere
CO2
CO2 CO2
Human activities and naturalprocesses add CO2 to theatmosphere, increasing the effect.
Photosynthesis removesCO2 from the atmosphere,decreasing the effect.
Nitrogen Cycle
The nitrogen cycle relies heavily on bacteria
• Atmospheric N2 is not available to plants– Soil bacteria convert gaseous
N2 to usable ammonium (NH4
+) and nitrate (NO3-)
– Some NH4+ and NO3
- are made by chemical reactions in the atmosphere
Nitrogen in atmosphere (N2)
Nitrogenfixation
Detritivores
Decomposition
Assimilationby plants
DenitrifyingbacteriaNitrates
(NO3–)
Nitrifyingbacteria
Nitrogen-fixingbacteria in rootnodules of legumes
Nitrogen-fixingsoil bacteria
Ammonium (NH4)
80%
Phosphorus Cycle
Depends on the weathering of rock
• Phosphorus and other soil minerals are recycled locally
• Weathering of rock adds PO43- to
soil– Slow process makes amount of
phosphorus available to plants low
Runoff
Sedimentation