1. Human Impact on Resources, Biodiversity, and Ecosystems

2. Types of Resources
natural resources – goods and services provided for by nature
renewable resources – replaced naturally in a reasonable amount of time
non-renewable resources
commons – resources owned by everyone

3. tragedy of the commons
renewable common resources which tend to be over-exploited
Why?
“if I don’t use them then someone else will so it might as well be me”

4. exploitation of resources
carrying capacity – the maximum size of a population that can be supported over the long term
maximum sustainable yield (MSY) – the greatest “use” of a renewable resource

5. Human Impact on Biodiversity
species biodiversity – the total number of different kinds of species
genetic biodiversity – the total gene pool for a given species
biosphere biodiversity – the total number of species in existence
- known species: 2 million
- unknown species: 3 – 50 million

6. Value of Biodiversity Why should we care about protecting other species?
Food
agriculture and meat production has led to a decline in species biodiversity as well as genetic biodiversity
Medicine
many modern medicines come from plant extracts
* biopiracy

7. Value of Biodiversity cont.
ecosystem sustainability
the greater the biodiversity, the greater the stability
* keystone species
commercial value
- ecotourism
- recreation; hunting, fishing, wildlife watching
- timber
intrinsic value
preservationist philosophy – existence of other species has value aside from any use we make of it

8. HIPPO

9. Human Causes of Biodiversity Decline
habitat destruction
deforestation, wetlands destruction, development
introduction of exotic species
most introduced species do not survive their new habitat – those that do, often out-compete native species (and are termed invasive)

10. human causes continued …
overuse (hunting, fishing)
* poaching
pollution
* climate change

11. Reduced Ranges Indian Tiger Range 100 years ago Range today
(about 2,300 left)
Fig. 9-8a, p. 191

12. Reduced Ranges Black Rhino Range in 1700 Range today
(about 2,400 left)
Fig. 9-8b, p. 191

13. Deliberately Introduced Species
Purple looselife
European starling
African honeybee
(“Killer bee”)
Nutria
Salt cedar
(Tamarisk)
Marine toad
Water hyacinth
Japanese beetle
Hydrilla
European wild boar
(Feral pig)
Fig. 9-11a, p. 193

14. Accidentally Introduced Species
Sea lamprey
(attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian muffle
Common pigeon
(Rock dove)
Formosan termite
Zebra mussel
Asian long-horned
beetle
Asian tiger mosquito
Gypsy moth larvae
Fig. 9-11b, p. 193

15. Kudzu
Fig. 9-12, p. 194

16. Fire Ant Invasion
1918
2000
Fig. 9-13, p. 195

17. Extinction Threats from Poaching
Profits of poaching
Causes of poaching: food, fur, pets, traditional medicines, trophies, eliminating pests, etc.
Bushmeat
Illegal pets and decorative plants

18. Bushmeat
Fig. 9-15, p. 196

19. Confiscated Products From Endangered Species
Fig. 9-18, p. 199

20. Extinction Threats from Climate Change and Pollution
Global Warming
Pesticide threats
DDT biomagnification (bioaccumulation)

21. Biomagnification of DDT
DDT in fish-eating
birds (ospreys)
25 ppm
DDT in large
fish (needle fish)
2 ppm
DDT in small
fish (minnows)
0.5 ppm
DDT in
zooplankton
0.04 ppm
DDT in water
ppm,
or 3 ppt
Fig. 9-16, p. 197

22. Litter Kills Seals
Fig. 9-19, p. 200

23. Extinction background extinction rate
- naturally occurring extinctions
- 99 % of all species are now extinct
local extinction
extinction of a population but not an entire species
species extinction
- disappearance of an entire species
- criteria for claiming this?
mass extinction
5 major episodes of extinction in Earth’s past

24. Extinction Crisis Question
the species-area relationship
lose 50% of a habitat, lose 15% of the biodiversity found there
fragmentation and edge effect
carving up a habitat into several smaller pieces increases edge habitat, decreases interior habitat and results in a loss of biodiversity
interior species, edge species

25. Fragmentation Cleared plots for grazing Highway Cleared plots
for agriculture
Fig. 8-10b, p. 161

26. Case Study: Amazonia
satellite images are used to measure species loss – How?
deforestation rate is slower than originally thought
however, the pattern of deforestation (fragmentation) may be causing a faster loss of species
primary (old growth) vs. secondary forests (less biodiversity)

28. Strategies for Protecting Biodiversity
laws and treaties
- CITES Convention on International Trade of Endangered Species
- MMPA Marine Mammal Protection Act
- ESA Endangered Species Act
endangered, threatened, special concern
captive breeding, zoos, game parks, cloning

29. Protecting Marine Biodiversity
why do we use preservation techniques with some species (whales) and conservation techniques with other species (fish)?
part of protecting biodiversity involves measuring populations and migratory patterns – how is that done with whales?

31. Case Study: Whale Preservation
conservation vs. preservation
commercial whaling
IWC 1986 commercial whaling ban
scientific whaling
subsistence whaling

32. Study of Whales
fluke prints
satellite tags
captivity