Community Interactions and Human impact

Chapter 42-45

__________ - All the populations that live

together in a habitat

___________ -the type of place where

individuals of a species typically live

_________- Everything it takes to survive survive and reproduce

Species Interactions• Most interactions are neutral

• ___________________ helps one species

and has no effect on the other

• ___________________ helps both species

• _________ and parasitism both benefit

one species at a cost to another

• Example- The Yucca and the yucca moth

– Each species of yucca is pollinated only by

one species of ______

– Moth larvae can grow only in that one

species of _______

•______________ promotes traits that help prey escape predation

•It also promotes traits that make _______________ more successful at capturing prey

__________

Obligatory ________________-

•Camouflage

•Warning coloration

•Mimicry

Moment-of-truth defenses

______________ Ecology

• Natural restoration of a damaged community

can take a very long time

• Active restoration is an attempt to reestablish

biodiversity in an area

• ______________ are actively working to

restore reefs, grasslands, and wetlands

Community _________

• Disturbances can cause a community to change in ways that persist even if the change is reversed

Species Introductions

•Introduction of a nonindigenous species

can decimate a community

•No natural ___________or controls

•Can outcompete _______________species

Examples of instability

• This predator ate native cichlids; drove many

species to extinction

• Rabbits were introduced, but without predators,

their numbers soared

Rabbits in ____________

_______________ in Lake Victoria

______________ in Georgia•No natural herbivores, pathogens, or competitors

•Grows over landscapes and cannot be dug up or burned out

Diversity by Latitude• Diversity of most groups is greatest

in __________; declines toward poles

Ant diversity

Human Effects

1. ________________cycle

2. __________ cycle

3. _____________cycle

•Phosphorus is part of _______________and all

________________

1. Phosphorous cycle

•most prevalent limiting factor in ecosystems

•phosphorus runoff is causing ___________ of waterways

Phosphorus Cycle

GUANO

FERTILIZER

ROCKS

LAND FOOD WEBS

DISSOLVED IN OCEAN

WATER

MARINE FOOD WEBS

MARINE SEDIMENTS

excretion

weathering

mining

agriculture

uptake by autotrophs

death, decomposition

sedimentation setting out leaching, runoff

weathering

uplifting over geolgic time

DISSOLVED IN SOILWATER,

LAKES, RIVERS

uptake by autotrophs

death, decomposition

2. ___________ cycle

photosynthesisTERRESTRIAL

ROCKS

volcanic action

weathering

diffusion

Bicarbonate, carbonate

Marine food webs

Marine Sediments

Atmosphere

TerrestrialRocks

Soil WaterPeat, Fossil

Fuels

Land Food Webs

•Atmospheric carbon is mainly ________________

•Carbon dioxide is added to atmosphere by

Aerobic respiration, volcanic action, burning fossil fuels

•Removed by _____________________

Greenhouse Effect• Greenhouse gases (CO2, CFCs, methane)

impede the escape of heat from Earth’s surface

2. Carbon cycle

•The average level is steadily increasingCO2

Human impactBurning of fossil fuels and deforestation are contributing to the increase

Global Warming

• Long-term increase in the temperature

of Earth’s lower atmosphere

2. Carbon cycle

• Nitrogen is used in _______________ and -_______________

• Main reservoir is nitrogen gas in the __________________

3. Nitrogen cycle

•Humans increase rate of nitrogen loss by clearing _______________________

•Humans increase nitrogen in water and air by using fertilizers and by burning _______________

•Too much or too little nitrogen can compromise plant health

Human impact

___________• Carbon oxides

• Sulfur oxides

• Nitrogen oxides

• Volatile organic compounds

• Photochemical oxidants

• Suspended particles

___________ Smog

• Gray-air smog

• Forms over cities that burn large amounts of coal and

heavy fuel oils; mainly in developing countries

• Main components are sulfur oxides and suspended

particles

Human Impacts •We use energy/ alter environment at astonishing rate

__________ smog• Brown-air smog

• Forms when sunlight interacts with components from automobile exhaust

• ______________ are the main culprits

•Weather pattern in which a layer of cool, dense air is trapped beneath a layer of ______ air

Thermal inversioncool air

warm inversion air

cool air

Acid Deposition

• Caused by the release of

__________ and nitrogen

oxides

• Coal-burning power

plants and motor vehicles

are major sources

Very high acidity (pH 4.2-4.4)

Sensitivity to acid deposition

Moderate to high acidity (pH 4.2-4.4)

______ Thinning• Seasonal loss of

ozone is at highest

level ever recorded

SouthAmerica

Antarctica

•Increased UV radiation

• UV damages ____

• UV affects plants productivity)

Result of ozone thinning

Protection efforts • CFC production halted• Methyl Bromide phased out• _____ recovery time

Garbage• Mostly developed nations

• 50% volume is ____________________

• Recycling can reduce pollutants, save

energy, ease pressure on landfills

• Almost ___ percent of Earth’s land is used for

agriculture or grazing

• About ____the Earth’s land is unsuitable for

such uses

• Remainder could be used, but at a high

_________ cost

Land use

Green Revolutions• Improvements in _________________

– But mechanized agriculture requires

pesticides, fertilizer, fossil fuel

• Improving genetic _________ of crop

plants

Deforestation

• ____________ acres logged each year– Wood is used for fuel, lumber

– Land is cleared for grazing or crops

•Soil leeching•Flooding

•forest loss are greatest in Brazil, Indonesia, Mexico, and Columbia

1620

1850

1850 (pockets only)

1990

Results

The __________

• Occurred in the 1930s in

the Great Plains

– Overgrazing and

prolonged drought left

the ground bare

• 1934 winds produced dust

storms that stripped about

_______ acres of topsoil

Desertification

Water Use and Scarcity• Earth’s water is too ________ for human

consumption

• ______________________ is expensive

• __________________ is the main use of

freshwater

Ogallala Aquifer•Overdrafts have depleted ______the water

from this nonrenewable source

Human Impact• We use energy/ alter environment at

astonishing rate

Coal 25%

Oil 37%

Natural gas 25%

Biomass 3%

Hydropower, geothermal, solar 7%

DEVELOPED COUNTRIES

Coal 25%

Natural gas26%

Nuclear___

Oil37%

Renewable- __%

Coal 25%

Oil 26%

Biomass 35%

Natural gas 7%

Hydropower, geothermal, solar 6%

Nuclear power 1%

DEVELOPING COUNTRIES

Oil25%

Oil26%

Renewable- __%

Developed countries Developing countries

Nuclear- __%

Natural gas7%

Fig. 45.16

What are the best alternatives??

1. Nuclear Energy

• Used extensively in some energy-poor developed countries

• Little support in the ________________

• Emits fewer air pollutants than burning coal, but creates radioactive wastes

• Potential for meltdown

________ Accident - 1986•Core meltdown at a nuclear power plant in the Ukraine

•____ immediate deaths, radiation sickness and death for others

•Cloud of radiation spread by winds across Europe

2. ___________ Energy• Photovoltaic cells use sunlight energy to

split water

• ________ gas produced in this way can be

used as fuel or to generate electricity

• Clean, renewable technology

3. ____ Energy

• An indirect use of solar energy

• Wind farms are arrays of ____________

• Can supplement needs of some regions but

is not dependable enough on it own

4. ______ • Energy is released when _______________

fuse

• This process produces solar energy

• Attempts to mimic this process on Earth require use of lasers, magnetic fields

• Not yet a _________________ viable energy source