Transcript 10b. Biomes_and_Biod..

Biomes and Biodiversity
Global ecosystems, the diversity of
life and the threats to biodiversity
The importance of climatic variables
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Temperature
Rainfall
Seasonality
Potential Evapotranspiration
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function of daily rainfall average, heat, wind
high heat, low rainfall = desert
low heat, low rainfall = tundra
seasonal shifting for all other biomes
Fig. 5.2
General distribution of biomes
Alternative Biome Map
Masai and Reticulated Giraffe
Fig. 5.12
Savannah, grassland and deciduous woodland
Topi and
Hartebeast
With a
Thompson
Gazelle
Fig. 5.10
Tall Trees Walk, Redwoods National Park, CA
Table 5.4
Biodiversity
• Important because of resilience
– For natural selection to occur, there must be
variation, heritability, and stress/advantage
– Biodiversity help ensure variation
• Many of our medicines came from the wild
– There might be important new medicines to be
found in our remaining diverse ecosystems
Biodiversity Hotspots
http://www.conservation.org/xp/CIWEB/strategies/hotspots/hotspots.xml
The 25 biodiversity hotspots contain 44 percent of all plant species and 35 percent of all
terrestrial vertebrate species in only 1.4 percent of the planet's land area.
The Brazilian Atlantic Forest
Hotspot Original Extent (sq. km.) 1,477,500
Hotspot Vegetation Remaining
121,600 Area
Protected (sq. km.)
33,000 Plant
Species
20,000 Plant
Endemics
8,000 Terrestrial
Vertebrates
1,668 Terrestrial
Vertebrate Endemics
563 Threatened
Species*
118 Critically
Endangered Species*
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Guinean Forests
of West Africa
Hotspot Original Extent (sq. km.)
1,265,000
Hotspot Vegetation Remaining
126,500 Area
Protected (sq. km.)
20,324 Plant
Species
9,000 Plant
Endemics
2,250 Terrestrial
Vertebrates
1,320 Terrestrial
Vertebrate Endemics
270 Threatened
Species*
74 Critically
Endangered Species*
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www.biodiversityhotspots.org/
The Bushmeat Dilemma
• Over 90% of the Ghanaian forest has undergone
conversion to cocoa plantations and other cash crops
• Traditional fishing fleets cannot compete with
subsidized European fish operations granted by treaty.
• Protein poor diets drive people to over harvest wild
animals, including remaining great apes and
monkeys.
• This is happening to a greater or lesser extent along
the West African coast.
Philippines
Hotspot Original Extent (sq. km.)
300,800
Hotspot Vegetation Remaining
21,000 Area
Protected (sq. km.)
25,995 Plant
Species
7,620 Plant
Endemics
5,832 Terrestrial
Vertebrates
1,114 Terrestrial
Vertebrate Endemics
555 Threatened
Species*
128 Critically
Endangered Species*
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California
Floristic
Province
Hotspot Original Extent (sq. km.)
Hotspot Vegetation Remaining
Area Protected (sq. km.)
Plant Species
Plant Endemics
Terrestrial Vertebrates
Terrestrial Vertebrate Endemics
Threatened Species*
Critically Endangered Species*
324,000
80,000
31,443
4,426
2,125
584
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Reasons for biodiversity decline
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Habitat conversion
Expanding human population/technology
Impacts of pollution
Soil erosion
Climate change
Genetic erosion – loss of genetic diversity
Introduced competition – invasive species
Former Assistant Secretary Of Interior Craig
Manson:
"If we are saying that the loss of species in
and of itself is inherently bad, I don't think
we know enough about how the world works
to say that." November 2003
(Mr. Manson is a former timber industry lobbyist and lawyer and
was in charge of the National Fish and Wildlife Service and
enforcement of the Endangered Species Act.)