Transcript Oct18BiomesandBiodiversity

Environmental Science
PowerPoint Lecture
Principles of Environmental
Science - Inquiry and Applications,
2nd Edition
by William and Mary Ann Cunningham
Chapter 5 - Topics
• Biomes
• Biodiversity
• How Do We Benefit from
Biodiversity?
• What Threatens Biodiversity?
• Human-Caused Reductions in
Biodiversity
• Protecting Biodiversity
Cunningham, Cunningham 2004
Part 1: Biomes
Biomes
• Broadly defined life zones
• Environments with similar climates,
topographies, soil conditions, and
biological communities
• Distribution mainly dependent on
temperature and precipitation –
only at broad scale used to determine
distribution of biomes
Biomes of the World – where humans mostly live?
Less
rain,
Cold
Lots
rain,
Hot
Does temperature
or precipitation limit
human habitation of
an area?
Cunningham, Cunningham 2004
FAO 1999, WRI 1998-1999
Ice, rock, desert
etc. = 32%
Forests,
woodlands = 33%
Potential ~ 66%
RESOURCE
EXTRACTION;
Humans use ~
40% of all global
net primary
production
GLOBE
Pastures =
23%
Ag =
10%
Built land
= 2%
UNITED
STATES
Forests,
woodlands =
28%
Desert =
~ 14%
Built
land
= 6%
Ag = 28%
Pasture,
Rangeland
= 31%
NY Times Oct. 4, 2002, p. A19, E. Becker
~ 87%
RESOURCE
EXTRACTION
Where do most
humans live and
survive the best?
Deciduous forests
Why Washington not
dominated by deciduous
forests?
- NEEDS ENOUGH RAIN DURING
GROWING SEASON since not
grow during winter and WA have
dry August
Evergreen Forest
Grow year round and in winter; grow in nutrient poor soils
Lower human population levels – difficulty finding food
(bark of tree not good, past considered desert for animals
since few big game animals)
Largest trees in world are evergreen, locations where
sequester carbon in forests
Mixed Forest
Mixed DeciduousEvergreen Forests
•Lots vines
•Lots big trees
More people live in dry
tropical forests than wet.
Why?
•Multilayer habitat with
different species
Dry forests –
•Lots of species
•soils more nutrient rich
•fewer insects, parasites
and fungal diseases so
healthier for humans
•can use fire
TROPICAL RAIN FORESTS
•Plants adapted to get
rid of water
•Lots of species
High
protecting themselves
species
by forming chemicals
diversity,at
high levels & highly
Large tree
toxic (but valuebiomasses
for
pharmaceutical,
drugs)
Lots
vines,
epiphytes
TEMPERATE
RAINFOREST,
WASHINGTON
How well could you
survive here?
•large pieces of dead wood
•lots habitat in dead wood
•endemic species on wood
•live > 1,000 yrs
•resistant to disease
•not fire susceptible when large
•high carbon sequestration rates
- important for mitigating rising
CO2 levels
•Thin needle like leaves, waxes,
minimize moisture loss
TEMPERATE CONIFEROUS
FOREST (Old growth Douglas-fir)
Alaska
Arctic
tundra
•Small trees
•Old trees but
very small
•Boggy
environments
•Animals
hibernate or
migrate
Black spruce
forest
•High diversity
in microbial
community
(not animals or
plant levels)
SAVANNA - Serengeti National Park
http://www.summitelgin.org/grassland_web/Tropical%20Grasslands/Plan
ts.html
Impalas in African savannas
http://www.summitelgin.org/grassland_web/Tropical%20Grasslands/Animals.html
Dry, thornshrubland,
Africa
•Deep roots
•Lots insects
•Plants store
water
•Adapted to
higher salt
levels
DESERT - Joshua Tree National Park
•Plants,
animals
adapted to
heat, low
HOH, repel
enemies
River
deposits –
chemicals,
effluent
Freshwater ecosystems are influenced by
surrounding terrestrial ecosystems. In turn, riparian
areas are productive because of nutrient deposition by
the river. Can also have pollutants transported by
river to terrestrial areas.
Freshwater ecosystems are impacted by anything that
happens uphill or upstream from them.
WETLANDS
Okefenokee Swamp, Georgia
WETLANDS
Coastal wetlands – salt
marsh ecosystems
One most productive
systems in the world
Major breeding, nesting
habitat for waterfowl,
shorebirds
Highly human impacted Burn easily
Coral reefs - Most productive ecosystems in world
in terms of energy cycling; strongly impacted by
land uses from land (sewage wastes)
Part 2: Biodiversity
Biodiversity - the variety of living things - three
types essential:
• Genetic diversity - variety of different
versions of the same genes within a species
• Species diversity - number of different
kinds of organisms within an ecosystem
• Ecological diversity - complexity of a
biological community (number of niches,
trophic levels, etc.)
Cunningham, Cunningham 2004
How many
species are
there?
Mammals
4,000
Tapeworms, flukes
12,000
Insects 750,000
Biodiversity Hotspots - endemic species
WHY ARE most of world’s biodiversity concentrated
near the equator (tropical rainforests, coral reefs),
islands, coastal areas, mountain tops?
Costa Rica, taxonomists identifying
all insects in the country
Food,
Drugs,
Medicine,
Ecological
benefits
Part 3:
How do we benefit
from biodiversity?
Where do we
collect most of
these species?
Mangosteens, Indonesia
Where do many of our
drugs that cause you to
hallucinate come from?
What is the link between
the old Salem witch trials &
LSD?
What is tobacco? What if I
told you it was an
insecticide? Was used by
Egyptians in the
mummification process?
Aesthetic and cultural benefits
Birdwatching and
other wildlife
observation
contribute more
than $29 million
each year to the
U.S. economy.
Part 4: What Threatens
Biodiversity?
Extinction - the elimination of a species
• Natural process - one species lost every 10
years
• Process been accelerated by human
impacts on populations and ecosystems
• E.O. Wilson - we are currently losing
thousands of species a year
Part 5: Human Activities That
Reduce Biodiversity
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Habitat destruction and fragmentation
Hunting and fishing
Commercial products and live specimens
Predator and pest control
Exotic species introduction
Diseases
Pollution
Genetic assimilation
Human Disturbance Map
Why is the tundra least
dominated by humans
(0.3%)?
Why are the tropical
forests only 25%
dominated by humans?
Why is 4/5 of temperate
broadleaved forests
dominated by humans?
Habitat Destruction - U.S. Wetlands
Past 200 years, more than half of the original wetlands
in the lower 48 states have been drained, filled, polluted,
or otherwise degraded. In the Midwestern states, up to
99% of all wetlands have been lost.
About 200 years ago,
the American
passenger pigeon was
the world’s most
abundant bird.
Population: 3-5 billion
Overhunting and
habitat destruction
caused its extinction.
Trade in Products from Endangered Species
Trade in Wildlife
About 75% of all saltwater tropical aquarium fish sold
come from coral reefs of Philippines & Indonesia
(commonly caught with dynamite or cyanide)
Introduction of Exotic Species
Classic example of an invasive species –
considered by some biggest threat to
biodiversity conservation
1905
Chapter 5 - Topics
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Biomes
Biodiversity
How Do We Benefit from Biodiversity?
What Threatens Biodiversity?
Human-Caused Reductions in Biodiversity
• Protecting Biodiversity
Part 6: Protecting Biodiversity
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Hunting and fishing laws
The Endangered Species Act (ESA)
Recovery plans
Minimum viable populations
Private land and critical habitat
Reauthorization of the ESA
International wildlife treaties
Jaguar, Belize
Conflicts in values
between conservation,
resource uses:
•Agriculture, food
production
•Animal species
conservation
•Preservation Maya ruins
•Persistence forest cover
•Political power all levels
TROPICAL FOREST
photo: Programme for Belize
•Persistence of Maya
culture, etc
Recovery Plans
Only 40 Florida
panthers remain
in Everglades.
We spend
millions of
dollars to protect
them, but
population may
be too small to
be viable.
Protecting biodiversity conflicts with
indigenous community needs to survive and
obtain sufficient food for themselves
Photo: K Vogt
Legacies of land
use resulted in:
Degraded
grasslands with
sheep, TUNDRA
Photo: B Hecht
Iceland
Lupine
Icelandic
BOREAL
FOREST
All
introduced
species –
not native
used to
restore
habitat
Photo: K Vogt
Siberian
Larch