Chapter 18 Conservation of Biodiversity. Why Should We Care About Biodiversity?. instrumental value goods and services intrinsic value. food medicine “ biopiracy ” timber recreation genetic information aesthetics. pollination clean water clean air climate modification.
Why Should We Care About Biodiversity? • instrumental value goods and services • intrinsic value
food medicine “biopiracy” timber recreation genetic information aesthetics pollination clean water clean air climate modification Value of Biodiversity
Nature’s Pharmacy Fig. 9-6, p. 189
The 6th Mass Extinction • Extinction- when there are no longer any of the species in the world. • We are currently losing approximately 50,000 species per year.
Estimating Extinction Rates • Species-area relationship • birds as indicators
Problems Estimating Extinction Rates • Extinction not easily documented over time – how do we know when a species is extinct? • Many species remain unidentified – how many species are out there, yet to be discovered? • Is it valid to use species-area relationship for all habitats/ecosystems? • fragmentation and edge effect complicate the impact on biodiversity
Genetic Diversity • Scientists want to conserve genetic diversity so that the species can survive environmental change and inbreeding will not occur. • Inbreeding occurs when individuals with similar genotypes, generally relatives, breed with each other.
HIPCO • H- Habitat Loss • I- Invasive Species • P- Pollution • C- Climate Change • O- Overharvested
Habitat Loss • For most species the greatest cause of decline and extinction is habitat loss. • Most habitat loss is due to human development
Reduced Ranges Indian Tiger Range 100 years ago Range today (about 2,300 left) Fig. 9-8a, p. 191
Reduced Ranges Black Rhino Range in 1700 Range today (about 2,400 left) Fig. 9-8b, p. 191
Invasive Species • Alien species (exotic species)- species that live outside their historical range. • Invasive species- when alien species spread rapidly across large areas. • Ex- Kudzu Vine, Zebra Mussel, Silver Carp
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
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
Kudzu Fig. 9-12, p. 194
Fire Ant Invasion 1918 2000 Fig. 9-13, p. 195
Pollution • Threats to biodiversity can come from toxic contaminants such as pesticides, heavy metals, acids, and oil spills.
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 0.000003 ppm, or 3 ppt Fig. 9-16, p. 197
Litter Kills Seals Fig. 9-19, p. 200
Overharvesting • When individuals of a species are removed at a rate faster than the population can replace them. • Ex- dodo, American bison, passenger pigeon.
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
Bushmeat Fig. 9-15, p. 196
Confiscated Products From Endangered Species Fig. 9-18, p. 199