a great deal of this topic revolves around · 2019-01-27 · a great deal of this topic revolves...

A great deal of this topic revolves around

the concept of SUSTAINABILITY

• Here’s a good short introduction to what

sustainability means. 2:00

• What can you do at home to make our world more

sustainable?

https://www.youtube.com/watch?v=FFCNCQleCuk

• Conservation biology is a goal-oriented science that

seeks to counter the biodiversity crisis, the current

rapid decrease in Earth’s variety of life.

• Extinction is a natural phenomenon that has been

occurring since life evolved on earth.

• The current rate of extinction is what underlies the

biodiversity crisis.

• A high rate of species extinction is being caused

by humans. Watch where you step. 3:30

Introduction to biodiversity

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

http://www.youtube.com/watch?v=giueWwwfGDc

Personal Grooming Products and Great Lakes Marine Life

Could removing dead skin cells from your face each night mean

doom for perch and other Great Lakes species?

Cosmetics manufacturers use these micro beads as abrasives in

facial and body scrubs. They are too tiny for water treatment plants

to filter, so they wash down the drain and into the Great Lakes.

The biggest worry: fish or turtles or seagulls think of them as

dinner; when eaten, the inert beads can deprive animals of

nutrients from real food or lodge in their gut, blocking digestive

systems. What would this do to a food web?

1. The three levels of

biodiversity are

genetic diversity,

species diversity, and

ecosystem diversity


Fig. 55.1

• Loss of species diversity.

• Much of the discussion of the biodiversity crisis

centers on species diversity.

• The U.S. Endangered Species Act (ESA) defines

an endangered species as one in danger of

extinction throughout its range, and a threatened

species as those likely to become endangered in

the foreseeable future.


• Here are a few examples of why conservation biologists are concerned about species loss.

• The IUCN reports that 13% of the known 9,040 bird species are threatened with extinction. That is 1,183 species!!!

• The Center for Plant Conservation estimates that 200 of the 20,000 known plant species in the U. S. have become extinct since records have been kept, and another 730 are endangered or threatened.

• About 20% of the known freshwater species of fish in the world have become extinct or are seriously threatened.


• Loss of ecosystem diversity.

• The local extinction of one species, like a

keystone predator, can affect an entire community.

• Some ecosystems are being erased from the Earth

at an unbelievable pace.

• For example, an area the size of the state of

West Virginia is lost from tropical forests each

year.


• Biodiversity is a

crucial natural

resource, and

species that are

threatened could

provide crops,

fibers, and

medicines for

human use.

• The loss of species also means the loss of genes.

• Biodiversity represents the sum of all the genomes

on Earth. Loss of genes = less adaptable.


Fig. 55.3

• Habitat destruction. By catastrophes or humans.

• Human alteration of habitat is the single greatest

cause of habitat destruction, responsible for 73% of

species designated extinct, endangered, or rare.

• About 93% of the world’s coral reefs have been

damaged by humans. Watch the Bleaching4:00

• How does cutting down a forest affect global

warming?

3. The four major threats to biodiversity are

habitat destruction, introduced species,

overexploitation and food chain disruption


https://www.youtube.com/watch?v=_ZfGIKiSwwQ

• Production in Freshwater Ecosystems.

• Solar radiation and temperature are closely linked

to primary production in freshwater lakes,

something the EOC wants you to remember.

• During the 1970s, sewage and fertilizer pollution

added nutrients like nitrates, to lakes, which

shifted many lakes from having phytoplankton

communities to those dominated by diatoms and

green algae.

• We’ve cleaned a lot of this up, but it continues to

be a problem.


• This process is

called

eutrophication,

and has undesirable

impacts from a

human perspective.

• Hey, how about

explaining that to us.


Hypoxic/anoxic zone in the Gulf of Mexico

Another big issue – plastic in the ocean

• See here what you will find in the middle of the

ocean. 1:30

https://www.youtube.com/watch?v=1qT-rOXB6NI


Fig. 54.15

• The carbon cycle fits the generalized scheme of

biogeochemical cycles better than water.


Fig. 54.17

• But the water cycle and the carbon cycle are linked in

many ways, including those that we impact.


Fig. 54.16

• The burning of

fossil fuels

releases sulfur

and nitrogen oxides

that react with water

in the atmosphere

to produce sulfuric

and nitric acids.

2. Combustion of fossil fuels is the main

cause of acid precipitation


Fig. 54.23a

• These acids fall back to earth as acid precipitation,

damaging ecosystems greatly.

• The acids can kill plants, and can kill aquatic

organisms by changing the pH of the soil and water.


Fig. 54.23b

• Rising atmospheric CO2.

• Since the Industrial Revolution, the concentration of

CO2 in the atmosphere has increased greatly as a

result of burning fossil fuels.

• Normally, this carbon would stay “locked up” in coal

and oil for a long time.

• Affects Carbon AND Water cycles.

• Let’s pick apart a video. 5 min.

4. Human activities may be causing climate

change by increasing carbon dioxide

concentration in the atmosphere

https://www.prageru.com/courses/environmental-science/climate-change-whats-so-alarming

• Measurements in 1958 read 316 ppm and increased

to 400 ppm in May 2013, highest in a few million

years


Fig. 54.26

• The greenhouse effect.

• Rising levels of atmospheric CO2 and methane may

have an impact on Earth’s heat budget.

• When light energy hits the Earth, much of it is

reflected off the surface.

• CO2, methane and other gases cause the Earth to

retain some of the energy that would ordinarily

escape the atmosphere.

• This phenomenon is the greenhouse effect.

• The Earth needs this heat, but too much could be

disastrous. Watch the methane in Siberia.


https://www.youtube.com/watch?v=rEHyj2adRlI

• Global warming.

• How will increasing levels of CO2 in the

atmosphere affect Earth?

• A doubling of CO2 will cause a 2º C increase in

the average temperature of Earth.

• Rising temperatures can cause polar ice cap

melting, which can flood coastal areas.

• The distribution of organisms has already

started to change. Ash borers kill baseball bats!

• It is important that humans attempt to stabilize

their use of fossil fuels.Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

But here will be the biggest problem with

carbon dioxide increase…

• Ocean acidification. 2 min.

• If sea level rises you can move to a different

place.

• If food chains collapse, you can’t move to a

different food chain.

• Once again – both Carbon AND water cycles are

affected.

https://www.youtube.com/watch?v=kxPwbhFeZSw

• Life on earth is protected from the damaging affects

of ultraviolet radiation (UV) by a layer of O3, or

ozone.

• Studies suggest that

the ozone layer has

been gradually

“thinning” since 1975.

5. Human activities are depleting the

atmospheric ozone


Fig. 54.27a

• The destruction of ozone probably results from the

accumulation of chlorofluorocarbons, chemicals

used in refrigeration and aerosol cans, and in certain

manufacturing processes.

• The result of a reduction in the ozone layer may be

increased levels of UV radiation that reach the surface of

the Earth.

• This radiation has been linked to skin cancer and

cataracts.

• So ozone up high is good, down low – bad.

• But when it traps UV radiation, ozone up high also

contributes to global warming!


• Introduced (aka – exotic, invasive) species.

• Introduced species are those that humans move from

native locations to new geographic regions.

• The Nile perch was

introduced into Lake

Victoria as a food fish,

but led to the extinction

of several native species.

• Pythons?


Fig. 57.7a

• Overexploitation.

• This refers to the human harvesting of wild plants

and animals at rates that exceed the ability of

those populations to rebound.

• The great auk was overhunted and became extinct.


Fig. 55.8

• The African elephant has been overhunted and

the populations have declined dramatically.

• The bluefin tuna is another example of an over-

harvested species.


Fig. 55.9

• Conservation biology highlights the relationship

between science, technology and society.

• High profile organisms may be the most popular due

to use as resources.

• Questions about human habitat needs also arise.

• The ecological role of the organisms must be

addressed as well.

• And then there is the economy.

• Decisions must weigh the costs and benefits. EOC!

3. Conserving species involves weighing

conflicting demands

• Restoration ecology applies ecological principles in

developing ways to return degraded areas to natural

conditions.

• Biological communities can recover from

many types of disturbances, through a series of

restoration mechanisms that occur during

ecological succession.

4. Restoring degraded areas is an

increasingly important conservation effort



Fig. 55.21

• Bioremediation is the use

of living organisms to

detoxify polluted

ecosystems.

• Restoration ecologists

use various types of

organisms, like plants that

absorb heavy metals, to

remove

many different types

of toxins from

ecosystems.


Fig. 55.22

• The impact of human activity on the ozone layer

is one more example of how much we are able to

disrupt ecosystems and the entire biosphere. Are

we entering the Anthropocene Era? 18 minutes if

time.

• So what to do??? (9 min.)

http://dotearth.blogs.nytimes.com/2011/05/11/confronting-the-anthropocene/

http://www.youtube.com/watch?v=mF_anaVcCXg&feature=relmfu

What does it all add up to?

• Too many people on earth for the amount of

resources each person uses.

• It can be measured by how much fossil fuel has to

be burnt for you to live the life you do.

• This is called your carbon footprint. Let’s

calculate here.

• Now some practice questions…

http://footprint.stanford.edu/calculate.html

Which of the following is NOT an example of

sustainable development?

A. Using one insect to control another that is

consuming crops

B. Planting crops that will grow in the shade to

reduce deforestation

C. Installing solar power cells to reduce the need to

burn fossil fuels

D. Using the slash-and-burn technique to clear land

for farming

To reduce the use of fossil fuels, automobile makers are

producing electric cars. Which of the following is an

advantage of using cars that run on electricity instead of

gasoline?

A. Electric cars use batteries that are easy to recharge

B. Electric cars cost less than gasoline-powered cars

C. Electric cars do not release pollutants into the environment

D. Electric cars are easier to operate than gasoline-powered cars

Which of these is the best reason for using wind

farms to produce electrical power?

A. The use of wind farms makes electricity less

expensive

B. The use of wind farms conserves nonrenewable

fuels

C. Wind farms have little environmental impact

D. Wind farms are suitable for most locations

A power company wants to build a new electric power

plant next to a river and use water from the river for

cooling. Which of the following should be studied before

deciding whether to let the company build the plant?

A. The price of the high-voltage wires used to transmit electricity

B. The effects of warmer water on the fish species that live in the river

C. The power company’s contributions to support local sports teams

D. The efficiency of the generators that the company plans to build

Human activities that increase carbon dioxide in the

atmosphere are likely to cause which of the following

environmental changes?

A. Tsunamis

B. Decreased plant growth

C. An ice age

D. A higher sea level

a great deal of this topic revolves around · 2019-01-27 · a great deal of this topic revolves...

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