Lecture 19.5 Flashcards
Biodiversity
The variety of the Earth’s species, the genes they contain, the ecosystem in which they live, and the ecosystem processes that sustain all life
Biodiversity components
1) Genetic Diversity
2) Diversity of Communities and ecosystems
3) Species Diversity
Genetic Diversity
Total genetic information contained within all individuals of a species (The number and relative frequency of all alleles)
Diversity of communities and ecosystems
The different biological communities and their associations with the physical environment
Species Diversity
All the species on Earth
Conservation Biology
Scientific discipline that focuses on preserving Earth’s biological resources
What is the underlying cause for the increased rates of extinction across all groups of life?
- Large human population (n~7+ billion)
- Human activities disrupt natural populations, communities and ecosystems
Unprecedented global decline of birds
-70% of the world’s 10,000 bird species are declining in numbers
-1 out of 8 species is threatened with extinction
-103 birds went extinct between 1800-2000
~12,000 expected to go extinct in the next century
~3/4 of threatened birds live in forests
Causes of bird decline and declines in biodiversity in general
1) pollution
2) overexploitation
3) Invasive species (predators and competitors)
4) Climate Change
5) Habitat loss and fragmentation
Pollution
Pesticides, oil spills, and lead poisoning
-Birds of prey are particularly vulnerable to pollution (Hawks, Eagles, Falcons)
Overexploitation
Excessive Harvesting of an animal or plant species
- Hunting, pet trade, other commercial uses
- 40-50% of birds harvested die during transportation
Climate Change
Shown to have a direct impact on bird population
Habitat Fragmentation Effects
- Habitat patches too small to support some species
- Limits to dispersal
- Genetic consequences of small populations
- Edge Effects: Quality of habitat that remains is jeopardized; easier access for predators, invasive species, and humans
