1. Chapter 5 Biomes & Biodiversity
How Do We Benefit from Biodiversity?
What Threatens Biodiversity?
Human-Caused Reductions in Biodiversity
Protecting Biodiversity
Cunningham, Cunningham 2002

2. 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

4. Biomes of the World – where humans mostly live?
Less rain, Cold
Does temperature or precipitation limit human habitation of an area?
Lots rain, Hot
Cunningham, Cunningham 2004

5. GLOBE 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
Pastures = 23%
Ag = 10%
Built land = 2%

6. UNITED STATES Desert = ~ 14% Forests, woodlands = 28% Built land = 6%
Ag = 28%
Pasture, Rangeland = 31%
~ 87% RESOURCE EXTRACTION
NY Times Oct. 4, 2002, p. A19, E. Becker

7. 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 the area of temperate broadleaved forests dominated by humans?

8. Where do most humans live and survive the best?

10. 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

11. 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

12. Mixed Forest
Mixed Deciduous-Evergreen Forests

13. More people live in dry tropical forests than wet. Why?
Lots vines
Lots big trees
Multilayer habitat with different species
Lots of species
Plants adapted to get rid of water
Lots of species protecting themselves by forming chemicals at high levels & highly toxic (but value for pharmaceutical, drugs)
Dry forests –
soils more nutrient rich
fewer insects, parasites and fungal diseases so healthier for humans
can use fire
High species diversity, Large tree biomassesLots vines, epiphytes
TROPICAL RAIN FORESTS

14. TEMPERATE RAINFOREST,
WASHINGTON

15. 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)

16. Old trees but very small
Alaska
Small trees
Old trees but very small
Boggy environments
Animals hibernate or migrate
High diversity in microbial community (not animals or plant levels)
Arctic tundra
Black spruce forest

17. Alaska - permafrost Layers of Ice TUNDRA Photo: K Vogt
Photo: H Bormann
TUNDRA

18. SAVANNA - Serengeti National Park Dry, thorn-shrubland, Africa
Impalas in African savannas

19. West Africa
Deserts. The Encroaching Wilderness. Ed. Allan and Warren Oxford University Press