Conservation and Biodiversity

biodiversity

• Variety of life at all levels of organization

• Genetic, species, population, community, ecosystem

• Biologist define at different levels depending on research aims

• Basic concepts apply across all levels

• Biological definition:

group of individuals that share certain characteristics and can interbreed, producing fertile offspring

richness

the number of species

evenness

relative abundance of species

Genetic Diversity

•Differences in DNA composition among individuals within a species

• Raw material for adaptation and evolution

interbreeding depression

• Genetically similar parents mate and produce “inferior” offspring

ecosystem diversity

•Number or variety of ecosystems

• Biotic communities

• Habitats

• Landscape level

• Size and shape of patches matters

• Connections between patches important

Diversity across groups

•Insects most diverse groups

• Within insects 40% are beetles

•Groups accumulate species by

• Adapting to local conditions

• Populations becoming divided

• Low extinction rates

global diversity

• Biodiversity not evenly distributed across planet

• Latitudinal gradient of richness increasing towards equator

• Why might there be more diversity near the equator?

• High NPP

• High plant diversity

• Stable climate

• No “recent” glaciation

Extinction

is the loss of all members of a species from all populations

biodiversity loss

extinction and expiration

Extirpation

• Loss of all individuals from 1 population

• First step on road to extinction

• Extinction is natural

• 99% of all described species are extinct

• Background extinction rate – natural 1 by 1 loss of species

• Species lifespan 1 – 10 million years

red list

• Threatened and endangered species listed and protected

Living Planet Index

summarizes population trends

• Vertebrate species from marine, terrestrial, fresh water systems

steady decreased over past 50 years

Pollution

Pollution harms organisms in many ways

• Air pollution degrades forest ecosystems

• Water pollution impairs fish and amphibians

• Toxins, garbage, oil, and chemicals impact organisms

• Pollution is a substantial threat; less significant than the public thinks

Hunting Fishing Poaching

•Hunting or harvesting threatens K- selected species

• Large, long-lived organisms that have few young can be hunted to extinction

• Elephants, gorillas, tigers, whales are at risk

•Governments have passed laws and signed treaties banning the hunting of

many species

Invasive Species

•Introduction of non-native species to new areas

• Can be accidental or intentional

• Outcompete or kill native species

•Island species are especially vulnerable

•Invaders lack natural predators, competitors, or parasites

climate change

•Impacts on the Earth’s climate system are global

• Extreme weather events (storms) increase stress

• Melting sea ice in the Arctic threatens polar bears

• Mountaintop species are losing their habitat

• A 1.5–2.5C temperature rise could put 20%–30% of plants and animals at increased risk of extinction

Importance of Biodiversity

• Ensures healthy ecosystem services

• Provides us with ecosystem resources

• Increases stability and resilience of natural systems

• Enhances food security

• Provide us with drugs and medicine

• Conservation biology

study of factors behind loss, protection and restoration of biodiversity

• Goal oriented

Conservation biologists

integrate evolution, extinction, ecology, environmental systems

• Develop solutions to species and habitat loss and degradation

Endangered Species Act of 1973

protects biodiversity

• Goal is to prevent extinction

• Forbids actions that destroy endangered species of their habitats

• US currently protects more than 1600 plants and animals