Post on 06-Mar-2018
transcript
Ecology
• Ecology = the study of interactions of living organisms with one another and with their physical environment (soil, water, climate, etc.)
• Who studies this? ecologists
• 2 sets of environmental factors
– Biotic and Abiotic Factors
Ecosystem Factors
Biotic Factors Abiotic Factors
Biotic Factors = factors in an ecosystem that are living Examples: -Tree -Rabbit -Frog
Abiotic Factors = factors in a ecosystem that are NON-living Examples: -Sun -Water -Weather -Fire
Levels of organization… can you remember?
1. Atom 2. Molecule 3. Cell 4. Tissue 5. Organ 6. Organ system 7. Organism 8. Population 9. Community 10. Ecosystem 11. Biome 12. Biosphere
6 Levels of Ecology focus on organism biome
1. Organism = one individual (you)
2. Population = 2+ of the same organism (our classroom)
3. Community = All types of living organisms in an area (our school population)
4. Ecosystem = All living organisms AND nonliving factors in an area (our school and everything in it)
5. Biome = group of similar ecosystems (our country)
6. Biosphere = all areas on earth where life exists (all life on Earth!)
What might you find if you turn over a log?
• Are all of these things competing for the same food?
• Each population feeds in different ways, on different materials, and at different times this leads to reduced competition
Niche • Niche = The role or function of an organism or species in an
ecosystem
– All the strategies and adaptations a species uses in its environment
– How it meets its specific needs for food and shelter
– How and where it survives
– Where it reproduces
– Includes all interactions with biotic and abiotic factors
Kind of like an organism’s “job”
• Competition = when organisms compete or fight over a limited resource
• Competition can be reduced by organisms having different niches in an ecosystem
What is competition?
• Predator = organism that hunts other organisms for food
• Prey = organisms that are hunted
• Populations of directly impact each other!
Predator/Prey Interactions
https://www.youtube.com/watch?v=vZynrBA91fY
• Density Dependent Factors = factors in the ecosystem that can change as a result of the population density (# of organism in an area)
• Examples:
– Food
– Shelter
– Water
– Disease
• For example, more organisms might mean less food
Density Dependent Factors
• Symbiosis = organisms living together
• 3 Types of symbiotic relationships
– Mutualism
– Commensalism
– Parasitism
Not all interactions among organisms involve eating each other…
• Mutualism = benefits both organisms in relationship
Mutualism
https://www.youtube.com/watch?v=Xm2qdxVVRm4
• Cattle Egrets live near cattle because the cattle stir up insects that the birds can eat. The cattle are neither benefited nor harmed by the birds presence!
Example: Cattle Egrets
• Parasitism = one organism benefits and the other is harmed
– PARASITES (like viruses) don’t immediately kill host… use it first – sometimes kill it later!
Parasitism
• Maximum population size of species that environment can sustain, given food, habitat, water and other necessities are available in environment
Carrying Capacity
All living things must have energy in order to maintain homeostasis (balance)
• Where does ALL energy originate?
• #1 source of energy = SUN (radiation)
• Energy flow is a “one way” street
Can you get energy from the sun?
• What organisms can use the sun’s energy for food? – Autotrophs!
• Autotroph = organisms that can make their own food (usually from sun or chemicals in environment) – Examples: plants, algae, photosynthetic bacteria,
chemotrophs
• AKA: Producers
What are organisms called that can’t make their own food?
• Heterotrophs = organisms that must “eat” their food to get energy
• Examples: protists, fungi, animals, you!
• AKA : Consumers
Food Web • Food webs show multiple pathways!
• ALL the possible paths energy could take!
What food relationships do you see taking place in the web to the left?
What are nutrients?
• If nutrients are made of matter, can we create or destroy nutrients?
• Matter (and nutrients) cannot be created nor destroyed!
Of what substance are all living things made?
• Carbon… and other nutrients!
• Nutrients = substances (elements/compounds) that are needed for life
How are nutrients cycled through ecosystems?
• Nutrients cycle between living and nonliving factors in the environment
• Matter is constantly recycled… never lost!
• What kinds of nutrients/chemicals are cycled in ecosystems?
What processes involve carbon?
• Carbon Cycle = the movement of carbon from living things into the atmosphere and back
• Involves: plants, animals, and atmosphere
Carbon Cycle
• All living things are made of carbon
• Where can you find carbon on earth?
• How does it move/cycle around?
Carbon Cycle Terms
• Photosynthesis = plants take in carbon and water and energy from the sun release oxygen and sugar (glucose-food)
• Respiration = cells take in oxygen and sugar (glucose-food) release carbon and water and energy!
• Eating = organisms use carbon in food to gain energy for growth
Carbon Cycle Terms
• Atmospheric CO2 = carbon dioxide in atmosphere (comes from fuel combustion, burning, respiration)
• Dissolved CO2 = carbon dioxide in bodies of water (comes from respiration of bacteria and fish)
Carbon Cycle Terms
• Fuel combustion = burning fossil fuels
• Fossil fuels = hydrocarbons that form from life forms millions of years ago (petroleum, natural gas, oil shale, tar sands)
Closed Carbon Cycle
•Closed carbon cycle = carbon burned originated in atmosphere and can be replaced within a human lifetime
•Example: burning wood, biofuel •Cellulose ethanol •Biodiesel •Wood chips •Torrification/gassification
Open Carbon Cycle
• Open carbon cycle = carbon burned cannot be replaced within a human lifetime
– Example: burning fossil fuels
Nitrogen Cycle
• Where do you use nitrogen?
– 78% of the air in the atmosphere is made up of nitrogen
• Why do we have to give plants nitrogen in fertilizer?
• Nitrogen must be converted to a USABLE form!
Nitrogen Cycle Terms
• Nitrogen fixer = bacteria that converts nitrogen from the atmosphere into nitrogen in the soil (usable form) for other plants to use
• Urea = nitrogenous waste released from animals in urine; puts nitrogen back in soil
Nitrogen Fixing Bacteria: https://www.youtube.com/watch?v=4NKGS4bj7cc
Life in a community
• How do plants and animals survive where they live?
• Various combinations of abiotic and biotic factors interact around the world.
• What does this mean about the different communities around the world?
Limiting Factor
• Limiting Factor = any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms
• Examples: availability of water/food, predators, temperature
• Recall that the carrying capacity is the maximum population size of species that environment can sustain, given food, habitat, water and other necessities are available in environment
Carrying Capacity: https://www.youtube.com/watch?v=QI2ixJeIxEU
What is the limiting factor?
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35 40 45 50
Foo
d p
rod
uct
ion
(m
g o
f gl
uco
se)
Temperature (C)
Food Production in Saltbush (Altriplex)
Temperatureand FoodProduction
Can factors indirectly affect populations?
• Lack of rain prevents grass from producing seeds
• Can this indirectly affect another population (other than just the grass?)
Ranges of tolerance
• What does corn need to survive?
• What if corn is grown in the shade… what will this do to the crop?
• Tolerance = the ability of an organism to withstand fluctuations in biotic and abiotic environmental factors
What is the range of tolerance?
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35 40 45 50
Foo
d p
rod
uct
ion
(m
g o
f gl
uco
se)
Temperature (C)
Food Production in Saltbush (Altriplex)
Temperature andFoodProduction
Succession: Changes Over Time
• If you stopped cutting the grass in your front yard, what would happen?
• In 1 year?
• 5 years?
• 90 years?
Succession
• Ecological Succession = the orderly, natural changes and species replacements that take place in the communities of an ecosystem
• Occurs in stages
• Each stage has different plants and animals
• Conditions of each stage are suitable for some organisms but not others
Succession
• Can you observe succession?
– It can take decades or even centuries to observe
• 2 types of succession:
– Primary succession
– Secondary succession
Primary Succession • Primary succession = the colonization of barren
land by communities of organisms
• Land must have: No living organisms – Example: island forming/land after lava flow
• Pioneer species = first species to take hold in an area – Example: lichen
• Different organisms
(usually algae, bacteria,
Fungus), that allow it to
mutuallistically survive
harsh conditions
Primary Succession
• What happens to the pioneer species (lichen, moss) over time?
• Decaying lichen and sediment develop soil
• Soil small plants
• Small plants die more soil bigger plants
• Over time the primary succession slows down and the community becomes stable
Climax Community
• Climax community = stable, mature community that undergoes little or no change in species
• May last for 100’s of years
• *** If its stable, does it still change?***
• YES!
• … but the changes are balanced!
Secondary Succession
• What if there’s a fire that destroys a community?
• What if a field isn’t replanted?
• What if a building is demolished and nothing is built on the site?
Secondary Succession
• Secondary succession = the sequence of changes that takes place after an existing community is severely disrupted in some way
• What are some possible disruptions?
http://www.youtube.com/watch?v=qIxyUcb2wqI
Secondary Succession
• What does secondary succession have that primary does not?
– SOIL!
• Will the species be the same?
• Will secondary succession still reach climax community status?
• Which will get there faster? (primary or secondary?)
What does the sudden drop in series 1 represent?
High
Species Biodiversity
Low
Time -->
Series 2
Series 1
• The biosphere, as you know, comprises all life on Earth
• Biome = a major biological community that occurs over a large area – A BIG group of LIVING
things
– Different kinds of species
– Large geographical area/ REGION
BIOMES
• Biomes are commonly identified by the Biome’s dominant plant species
How are biomes commonly identified?
Aquatic
• WATER
• Examples:
– Ocean
– Creek
– River
2 major kinds of BIOMES
Terrestrial
• LAND
• Examples:
– Forest
– Desert
– Grasslands
Saltwater
• Ocean
• Marine
• Salt Lakes
3 kinds of Aquatic Biomes
Freshwater • Pond, lake,
river
Estuary
• Mix of fresh and saltwater
• Marsh/ICW
• LIGHT is a major resource when talking about aquatic biomes.
• 2 zones based on the AMOUNT of light:
Aquatic Biomes and LIGHT
Photic light shallow water
Aphotic no light deep water
• Tundra
• Taiga
• Temperate Forest
• Grassland
• Desert
• Tropical Rain Forest
6 major Terrestrial Biomes
• Northern/Polar regions
• Very cold temperatures (long winter/short summer)
• Permafrost = permanent layer of frost in the ground – only small plants can grow
Tundra
• Mountainous regions with mostly conifers
• Cold winters, cool/short summer
• Conifer = mainly pines
Taiga
• Clearly defined seasons
– Mild winters/warm summers
• Some conifers, but mostly deciduous trees
• Deciduous Tree = tree that loses its leaves in the fall (oak, maple)
Temperate Forest
• Very little rain (<3cm/yr)
• Hot days/Cold nights
• Animal adaptations:
– Nocturnal = move/hunt at night to avoid heat
– Burrow = live in hole to avoid heat
– Must conserve water!
Desert
• Rains almost daily
• Located very close to equator (most sun)
– No seasons
• Most “biodiverse”: greatest variety of organisms in an area
Tropical Rainforest
As you can see, Biomes are classified by both Abiotic and Biotic factors!
• Each biome has different:
• Temperature
• Rainfall
• Altitude
• Latitude
• Types of plants and animals
• This booklet should be directed toward 5th graders.
• Your goal is to educate them on the six different terrestrial (land) biomes:
– Tundra, Taiga, Desert, Grasslands, Temperate Forest, and Tropical Rain Forest.
• Try to find creative and interesting ways to represent the following information using one page per biome.
Biome Booklet Time!
• Global location/ Description
• Climate/ Seasonal Extremes
• Average rainfall
• Animals (minimum of 2)
• Plants (minimum of 1-2)
• Describe at least one adaptation for plants AND animal in each biome
• Interesting facts (minimum of 2)
• **Include a decorative cover for your brochure!!!*** Use pictures/drawings/collage***
• Green and Black Text Book pgs 80-99 will help you!
Biome Booklet
What is biodiversity?
• Bio = life
• Diversity = differences among organisms
• Biodiversity = the variety of living organisms found in an area
Biodiversity varies around the world:
Do you see a pattern?
• Number of species of mammals:
– Canada – 163
– US – 367
– Mexico – 439
• In one hectare of forest you are likely to find:
– Peru – 300 tree species
– US – 30 tree species or less
Why is biodiversity important?
• Organisms are adapted to live together!
• Ecologists know many relationships – many have yet to be discovered
• Biodiversity decreases competition, and increases the amount of genetic material in the environment!
What is meant by the phrase “Life depends on life?”
• Animals need plants
• Plants couldn’t exist without animals to pollinate
• Plants need decomposers to break down nutrients
• Living things create niches for other living things!
Importance to People • What does biodiversity offer to Humans? • Biodiversity gives humans:
– Oxygen – Diverse diet – Materials (clothes, furniture, buildings) – Medicinal supplies (world pharmacy)
• Penicillin cam from the mold Penicillium • Antimalarial drug came from the cinchona tree
Preserving biodiversity ensures there will be living things to use in the future!
Loss of Biodiversity Extinct Endangered Threatened
Disappearance of a species
numbers so low that extinction is possible
Population declining rapidly
Ex) Dodo Bird, Tasmanian tiger
Ex) Peregrine Falcon, Black Footed Ferret
Ex) Polar Bear, Boreal Toad
Threats to Biodiversity
• Species are usually well adapted to their habitats…
• What happens when these habitats are changed?
Habitat Loss
• Habitat loss = removal/disappearance of habitat
• Effect: organism are displaced (must go somewhere else)
• Ex:
– deer in your yard
– bears in garbage
Habitat Fragmentation • Habitat fragmentation = obstruction (road,
development, etc) that separates a habitat into sections
• Example: Road through a forest prevents animals/plants from moving to other side
Habitat Fragmentation
• Can cause problems with
– Migration
– “island effect” or – smaller less biodiversity
– Invasion of exotic species
– Lack of reintroduction after fires
– Changes is climate
– Edge effect
Habitat Degradation: Pollution
• Pollution can be air, water, or land
• Examples:
• Acid Precipitation
• CFC’s in atmosphere
Introduction of Exotic/Invasive Species
• Do not belong in habitat
• Few/no predators in new habitat
• Reproduce/spread out of control
Conservation of Biodiversity
• Conservation biology = a new field that studies methods and implements plans to protect biodiversity
• Effective strategies are based on ecological principles
• Many species are threatened because of people, so working with humans is a major part of conservation biology
Legal Protection • US Endangered Species Act
• CITES (Convention on International Trade of Endangered Species)
Habitat Preservation
• What does it mean to be sustainable?
• Sustainable use = using resources wisely – waste less
• Habitat Corridors = connect pieces of land to overcome habitat fragmentation
Preservation
• What does a reintroduction program try to do?
– Example: California condors
• What does a zoo/captivity aim to do?
• What is a seed bank?
Preservation
• Captivity – under human control
• Reintroduction – putting species back in natural environment