PowerPoint Presentation on sustaining biodiversity.

1. Sustaining Biodiversity: The
Ecosystem Approach

2. Key Questions
■ What are the major threats to forest ecosystems?
■ How should we manage and sustain:
■ forests?
■ grasslands?
■ aquatic ecosystems?
■ Address this first--What is the ecosystem approach to
sustaining biodiversity?
■ How can humans help sustain the Earth’s biodiversity?

3. Human Impacts on Biodiversity
■ Human “footprint”
■ Disturbing the land- humans have disturbed
50 - 83% of Earth
■ Destruction of wetlands
half world’s wetlands lost in past 100 years
■ Deforestation
■ Aquatic biodiversity-
27% coral reefs severely damaged-
75% fish are fished at or above limit
■ Premature extinctions-
current extinction rate likely 1,000 - 10,000 times
greater than before humans

4. What is the ecosystem approach to
sustaining biodiversity?

5. The Ecosystem Approach
The Species Approach
Tactics
• Protect habitat areas through
private purchase or
government action
• Eliminate or reduce
populations of nonnative
species from protected areas
• Manage protected areas to
sustain native species
• Restore degraded ecosystems
Tactics
• Legally protect
endangered species
• Manage habitat
• Propagate endangered
species in captivity
• Reintroduce species
into suitable habitats
Strategy
Preserve sufficient areas of
habitats in different biomes
and aquatic systems
Strategy
• Identify endangered
species
• Protect their critical
habitats
Goal
Protect populations of species
in their natural habitats
Goal
Protect species
from
premature
extinction
Human
Impacts on
Biodiversity

6. Biodiversity Hot Spots
Hotspot Definition =
Area especially rich in
plant and animal
species: contains at
least 1500 native plant
species
Question
a unique area with
species found
nowhere else.

7. Biodiversity Hotspots: Islands
(and areas that resemble islands like, like mountains
surrounded by lowlands or development)
Islands often lack species
richness, but tend to have
unique, specialized
organisms.
Theory of Island
Biogeography: Large,
close islands will have more
diversity and colonization
(and less extinction) than
small, far islands.
Characteristics:
- lack of fear of predators
- large size
- flightless birds
- swimming iguanas
- tropical penguins
Influx of generalist species
can devastate island habitats.

8. What are the major threats to
FOREST ecosystems?

9. Support energy
flow and
chemical cycling
Reduce soil
erosion
Absorb and
release water
Purify water &
air
Influence local
and regional
climate
Store carbon
Provide wildlife
habitats
Fuelwood
Lumber
Pulp to make
paper
Mining
Livestock grazing
Recreation
Jobs-
1 of 4 people
depend on forests
for living
Major Services of Forests
Forests
Ecological
Services
Economic
Services
Ecological
services of
world’s
forests
valued at
$33.2 trillion
per year!!!
Value of ecological
services much
greater than value of
economic services
>>>
Much greater than

10. Types of Forests
Old-growth- not seriously disrupted
for at least several hundred years
Second-growth - results from
secondary succession
Tree plantation
or tree farm -
managed tract of
uniformly aged trees of
one or two species. Clear
cut when commercially
valuable, then replanted.
Less diverse & less
sustainable than old or 2nd

11. Clear-cutting
Reduces biodiversity
Disrupts ecosystem processes
Destroys and fragments some
wildlife habitats
Leaves moderate to large openings
Increases soil erosion
Increases sediment water pollution and
flooding when done on steep slopes
Eliminates most recreational value for
several decades

12. Trade-Offs
Clear-Cutting Forests
Advantages Disadvantages
Higher timber yields
Maximum economic return
in shortest time
Can reforest with genetically
improved fast-growing trees
Short time to establish new
stand of trees
Needs less skill and planning
Best way to harvest tree plantations
Good for tree species needing
full or moderate sunlight for growth
Reduces biodiversity
Disrupts ecosystem processes
Destroys and fragments some
wildlife habitats
Leaves moderate to large openings
Increases soil erosion
Increases sediment water pollution and
flooding when done on steep slopes
Eliminates most recreational value for
several decades
Tradeoffs of Clear-cutting Forests

13. Tropical Deforestation
■ Rapid and increasing – over 11 football
fields lost per minute (Nature Conservancy
quotes 1 field per SECOND), half of historical
rainforests have been lost—most since 1950
■ Loss of biodiversity at least half world’s
terrestrial species live in tropical forests (on
6% of earth’s land)
■ Deforestation for croplands, logging and
ranching
■ Problems measuring deforestation-
satellite images difficult, countries misreport,
varying definitions
■ Causes of tropical deforestation = pop.
Growth, poverty, gov. subsidies, debt, failure to
value ecological services
■ Burning: contributes CO2 to global
warming
■ Possible solutions - prevention &
restoration

14. Protect most diverse and endangered areas
Educate settlers about sustainable
agriculture and forestry
Phase out subsidies that encourage
unsustainable forest use
Add subsidies that encourage
sustainable forest use
Protect forests with debt-for-nature swaps,
conservation easements, and conservation
concessions
Certify sustainably grown timber
Reduce illegal cutting
Reduce poverty
Slow population growth
Reforestation
Rehabilitation of degraded areas
Concentrate farming and ranching on
already-cleared areas
Restoration
Prevention
Solutions
Sustaining Tropical Forests
Protecting Tropical Forests

15. © 2006 Brooks/Cole -
Natural Capital Degradation
Deforestation
• Decreased soil fertility from erosion
• Runoff of eroded soil into aquatic systems
• Premature extinction of species with
specialized niches
• Loss of habitat for migratory species such as
birds and butterflies
• Regional climate change from extensive
clearing
• Releases CO2 into atmosphere from burning
and tree decay
• Accelerates flooding
Harmful Effects of Deforestation
ABOUT 46% OF
WORLD’S
FORESTS HAVE
BEEN
CUT DOWN IN
THE LAST
60 YEARS

16. Surface and Crown Fires
Ground fire:
underground surface fire, common in
northern peat bogs or
when there is significant dead wood on
forest floor (can be intense)
Least intense More intense and destructive of life
Mature trees & animals escape
Help prevent more destructive fires
Free mineral nutrients from decomposing litter
Release seeds from cones
Stimulate germination
Help control diseases and insects
Provide young tender vegetation to wildlife

17. © 2006 Brooks/Cole -
Thomson
Solutions
Sustainable Forestry
• Grow more timber on long rotations
• Rely more on selective cutting and strip cutting
• No clear-cutting, seed-tree, or shelterwood cutting
on steeply sloped land
• No fragmentation of remaining large blocks of forest
• Sharply reduce road building into uncut forest areas
• Leave most standing dead trees and fallen timber for
wildlife habitat and nutrient recycling
• Certify timber grown by sustainable methods
• Include ecological services of trees and forests in
estimating economic value
Sustainable Forestry
Conserves
biodiversity,
water & soil
resources
Sustainable
management intensive
management of as little as 20%
of world’s forests could meet
current and future demand for
commercial wood / fiber
Combine aspects of a number
of management techniques
such as SELECTIVE
CUTTING.

18. Kenaf and other fast-growing plants
Yields more paper
pulp per land area
than tree farms &
require less
pesticides &
herbicides.
Holds potential to
greatly reduce
pressure to cut trees
for paper.

19. How should we manage and
sustain grasslands?

20. Rangelands & Overgrazing
■ Rangelands = unfenced supply vegetation, for
grazing (grass-eating) and browsing (shrub-
eating) animals.
■ Grasslands ecological services; soil formation,
erosion control, nutrient cycling, storage of
atmospheric carbon dioxide in biomass, and
maintenance of biodiversity.
■ Overgrazing: caused a loss in productivity in as
much as 20% of the world’s rangeland.

21. We can manage rangelands
more sustainably
■ Control the number of grazing animals
■ Rotational grazing
■ Provide supplemental feed
■ Suppress the growth of unwanted invader plants by
use of herbicides, mechanical removal, or controlled
burning or use controlled, short-term trampling by
large numbers of livestock.

22. Restoration of a Stream Bank
Area restored in 10 years after banning grazing and off-road vehicles.

23. ●Question 2
What is Ecological Restoration ?

24. Ecological Restoration
“process of repairing damage
caused by humans to the
biodiversity & dynamics of
natural ecosystems”
■ Restoration, rehabilitation and
replacement
■ Creating artificial ecosystems
Principles of Ecological Restoration:
1. Mimic nature
2. Recreate important ecological
niches
3. Rely on pioneer, keystone and
foundational species and natural
ecological succession
4. Control or remove nonnative
species
Accomplishments in Costa Rica: from a high deforester, to very low.
Present forest cover at 50% of nation (up from 21% in 1987)

25. How can we help to sustain
aquatic biodiversity?
Only 0.8% of
oceans are
protected
worldwide (as
opposed to 5%
of land).

26. General Patterns of Marine Biodiversity
■ Greatest biodiversity in coral reefs, and deep-
sea floor
■ Biodiversity is higher near coasts than open sea
■ Biodiversity is higher on the ocean bottom than
the surface
■ Loss and degradation of habitat is greatest threat
■ Damage to coral reefs and other habitats
■ Dredging / trawler operations destroy bottom habitats
■ Overfishing
■ Premature extinction
Human Impacts

27. Degradation of the Ocean Floor

28. Why Is It Difficult to Protect Marine
Biodiversity?
■ Coastal development
■ Unseen pollution
■ Lack of protection in international waters

29. Major commercial fishing methods
Video Tutorial - Click Here

30. Fig. 8-30, p. 181
Fishery Regulations
Set catch limits well below the maximum
sustainable yield
Improve monitoring and enforcement of
regulations
Economic Approaches
Sharply reduce or eliminate fishing subsidies
Charge fees for harvesting fish & shellfish from
publicly owned offshore waters
Certify sustainable fisheries
Protected Areas
Establish no-fishing areas
Establish more marine protected areas
Rely more on integrated coastal management
Consumer Information
Label sustainably harvested fish
Bycatch
Use wide-meshed nets to allow escape of smaller
fish
Use net escape devices for seabirds and sea
turtles
Ban throwing edible and marketable fish back into
the sea
Aquaculture
Restrict coastal locations for fish farms
Control pollution more strictly
Depend more on herbivorous fish species
Nonative Invasions
Kill organisms in ship ballast water
Filter organisms from ship ballast water
Dump ballast water far at sea and
replace with deep-sea water
Managing Fisheries - Solutions

31. What Can We Do?
■ Preserve world’s biological “hot spots”
■ Save the old-growth forest
■ Map world biodiversity so we know what we have
■ Identify and protect marine “hot spots”
■ Protect and restore lakes and streams
■ Ensure the full range of ecosystem types in the
conservation strategy
■ Make conservation profitable
■ Initiate worldwide ecological restoration projects