The Nature Of Ecosystems + Human Evolution and Ecology Flashcards
1
Q
Biosphere
A
Portion of Earth that contains living organisms
2
Q
Ecosystems
A
Organisms + physical and chemical environment
3
Q
Ecosystems in relation to balance
A
- Interactions in ecosystems maintain balance, which maintains the balance of the biosphere
- Human activities can alter the interactions between organisms and their environment, tampering with the overall balance
4
Q
Biomes
A
Several distinctive major types of earthly ecosystems
Two main divisions are terrestrial and aquatic
Types of Biomes:
- Rain forest
- Savanna
- Grasslands
- Deserts
- Marine
5
Q
Biotic Components of an Ecosystem
A
- Living components
- Generally organized as Autotrophs and/or heterotrophs
6
Q
Autotrophs
A
- Can automatically make their own food by turning an inorganic substance into an organic one
- Also called produces (because they produce food)
7
Q
Heterotrophs
A
- Need a source of organic nutrients
- Are consumers
- Split into Herbivores, omnivores, detrius feeders and carnivores
8
Q
Herbivores
A
- Eat plants or alage
9
Q
Carnivores
A
- Eat other animals
10
Q
Omnivores
A
- Eat both plants and animals
11
Q
Detritus Feeders
A
- Organisms that feed on decomposing particles of organic matter
12
Q
Niche
A
- The role of an organism in its ecosystem
13
Q
Diagrams of interactions of all populations in an ecosystem
A
- Illustrated Energy flow.
- Chemical cycling
14
Q
Energy Flow
A
- Can be represented by food web/chain
15
Q
Trophic Level
A
- Composed of all of the organisms that feed at a particular link in a food chain.
- Only about 10% of the energy of one trophic level is available to the next trophic level
- The first series of animals are the producers, the second are the primary consumers, the third are the secondary consumers
16
Q
The Water (hydrologic) Cycle
A
- Evaporation (called transpiration for plants): The sun causes freshwater to turn to gas and rise
- Condensation: Occurs when the water enters the atmosphere. Water molecules join together when they are cold and reform as a liquid
- Precipitation: The water molecules become too heavy, and fall back to earth
17
Q
Runnoff
A
- Water that falls directly into bodies of water
18
Q
Groundwater
A
- Water that falls and then sinks into the ground
19
Q
3 Ways Humans Interfere with the water cycle
A
- We withdraw water from aquifers
- We clear vegetation from and build man-made structures
- We interfere with the natural processes that purify water and instead add pollutants such as sewage and chemicals to water
20
Q
Difficulty of Increasing Water Supply
A
- It takes a long time to build structures that transfer water
21
Q
The Carbon Cycle
A
- There is a perpetual exchange pool for carbon dioxide
22
Q
Reservoirs Hold Carbon
A
- Living and dead organisms contain organic carbon and serve as one of the resevoirs for the carbon cycle
23
Q
Fossil Fuels
A
- Animal remains that have been transformed into coal, oil and natural gass
24
Q
Climate Change
A
- Humans have been putting too much carbon into the air through fossil fuels, and now the earth is heating to insane temperatures
25
Greenhouse effect
- Allows solar radiation to hit the earth, but doesn't let them escape
26
Global Warming
- Rise in earth's tempeture
27
Nitrogen cycle
- Nitrogen makes up ~78% of the atmosphere in a form that is unusable by plants.
Therefore, nitrogen can be a nutrient that limits the amount of growth in an ecosystem.
1. Nitrogen fixation
2. Nitrification
3. Denitrification
28
Nitrogen fixation
- Occurs when the nitrogen gas is converted to ammonium, a form that plants can use
29
Nitrification
def: The production of titrates during the nitrogen cycle
- Nitrogen gas is converted to nitrate in the atmosphere, where high energy is available for nitrogen to react with oxygen. This energy may be supplied by cosmic radiation, meteor trails, or lightning
- Ammonium in the soil from various sources, including decomposition of organisms and animal wastes is converted to nitrate by soil bacteria
- Nitrate-producing bacteria convert ammonium to nitrate. Nitrate-producing bacteria convert nitrite to nitrate
30
Denitrification
The conversion of nitrate back to nitrogen gas (which then enters the atmosphere)
31
Why does acid deposition occur?
- Nitrogen Oxides and Sulfur Dioxides enter the atmosphere from the burning of fossil fuels
32
Reservoir of Phosphorus cycle
- Ocean sediments
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How do phosphate in ocean sediments become available?
- Geological change exposes sedimentary rocks due to weathering. Weathering slowly makes phosphate available to the biotic community
34
Phosphate
- limiting nutrient in ecosystems
35
What might imbalances in the phosphorus cycle lead to?
- Cultural eutrophication
36
Ways that humans interfere with the nitrogen cycle
- Fertilization is produced from nitrogen which nearly doubles the fixation rate. Fertilizers then run into lakes/rivers which lead to blooms of algae called algae blooms. Decomposers have to use a lot of oxygen in the water to feed on them once they die, which gets rid of a lot of the algae in oxygen in the water
- Acid deposition. This happens when nitrogen oxides and sulfer oxides enter the atmosphere because of the burning of fossil fuels where they join with water to form acid rain
37
Humans interference- Phospurus cycle
Humans mine, which put excess phosphorus in the water
38
What is the growth rate of the human population determined by?
The difference between the # of people born per year and the # who die each year
39
Carrying Capacity
The maximum population the enviornment can support for an extended period.
40
MDC
- stands for More devoloped countries
| - grow due to immigration, lower death rate and higher birth rate
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LDC
- stands for less devoloped countries
- less deaths and higher birth rate
- most of the growth will occur in Asia
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3 age groups populations
- prereproductive
- postreproductive
- reproductive
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Replacement Reproduction
- People are living longer, so populations growth increases further
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Increasing Water Supplies
- Humans have to use ways of increasing water availabiility
45
Dams
- drawbacks include the damming of certain rivers can make it so they don't flow as they once did. They also cause alot of water loss
46
Aquifires
- a body of permeable rock which can contain or transmit groundwater.
- running out
47
Resources that humans need
- land
- water
- food
- energy
- minerals
48
Land
- needed for homes, agriculture, eletrical power plants, manufacturing plants, highways, hospitals, and schools
- Humans are not distrubuted equally on land
49
Beaches and Human Settlement
- 40% of population lives near the coast line which leads to: beach errosion, loss of habitat, loss of buffer zones for storms
50
Semiarid lands and human settlement
- in danger of desertication where they turn into deserts. This happens due to over-grazing. it leads to famine.
51
Tropical Rain forests and human settlement
- Subject to deforestation and dsertification because removing trees removes nutrients.
52
Aquifers/Groundwater pumping
- provides freshwater
| - can lead to subsidence, sinkholes, saltwater intrusion
53
Types of sources of water pollution
- point sources
- nonpoint sources
- final receptors: costal regions
- consequense is the loss of speices
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Point sources
- sources of water polution that can be traced to a specific source
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nonpoint sources
- sources of water pollution that can NOT be identified
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Final receptors
- costal regions feel the effects of water polution
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Conservation of Water
- Planting drought resistant crops,
- Using drip systems
- Reusing water
58
Food as an element needed by humans
- Sources: growing crops, raising animals, and fishing.
| - A large portion of our diet is obtained by dying
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Harmful farming practices
- Planting a few genetic varieties/monoculture
- Heavy use of fertilizers, pesticides and herbicides
- Over- irragation
- Excessive fuel consumption
- Planting patterns promotes soil erosion
- Domesticaton of livestock creates pllutants and energy intensive
60
Improving food supply
- polyculture: planting more than one type of plant in the same area
- contour farming
- Biological pest control
- genetically modified food
61
Energy
- Nonrenewable sources
Fossil fuels: 78%
Nuclear power: 6%
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Renewable Sources of Energy
- Hydropower
- Geothermal energy
- Wind power
- Solar energy
- Alternate fuel sources
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Hazardous Wastes
- Minerals
- Sythesized chemicals
- Raw sewage
- Leads to: health problems, depletion of the ozone layer
- Subject to biological magnification
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Biodiversity
- the variety of live on earth
| - measured by the # of species
65
Extinction
loss of speicies
66
Biodiversity crisis
- so many species are going extinct that variation is impaired
67
Habitat loss
- Habitat in which organisms naturally survive can come overtaken/altered by humans
- Tropical rain forests and coral reefs are the most affected
68
Loss of biodiversity- Alien species
- Non native speices (also called exotics)
- Some are invasive
- Introduced by colonization, horticulture, agriculture, accidental transport
69
Pollution
- affects health of organisms (particuarly endocrine and reproductive functions)
- causes enviornmental changes like acid deposition, global warming, and depletion of ozone layer
70
Overexploitation
- # of organisms taken from an ecosystem > replacement of those organsims.
- Taken for food, medicine, decoration/collection
- creates a positive feedback loop, where the more they disapear, the more valuble they are (their cost goes up)
- Can have domino effect in food web
71
Ecology
The study of ecosystems/how humans interact with the world
72
Food Web
The various interconnecting paths of energy flow
73
Biomass
The number of organisms multiplied by the weight of organic matter contained in one organism
74
Biotic Factors
- Living factors
| Ex: Trees, platypus,
75
Abiotic Factors
- Non living components
| Ex: Rock, soil, air
76
Phosphorus Cycle
- In the phosphorus cycle the phosphorus is trapped in oceanic sediments and gets moved onto land The weathering of the rocks causes it to move back into the oceans. The amount of phosphate available in a community is generally being used in various food chains
