sustaining biodiversity species Flashcards
what is local extinction
a species is extinct in one area but still lives in the biological community
ecological extinction
a few members are left but no longer play a role in the biological community
biological extinction
species not found anywhere on the planet
extinction spasm
large number of species go extinct in a very short time
mass extinction
25%-75% or more
background extinction
the natural rate of extinction needed for speciation
characteristics of extinction prone species
low reproductive rate (k-species) feeds at high trophic level, rare, fixed migratory pattern, commercially valuable
Species-area relationships estimated extinction
90% loss of
habitat results in 50% species loss
Population viability analysis (PVA)
Species-specific calculation on how
many years before the population will
become extinct
Minimum viable population (MVP)
Minimum number a population can
have and survive in the wild
Minimum dynamic area (MDA)
minimum amount of area a species
needs to survive
endangered species
So few individuals that
the species could soon become extinct over
all or part of its natural range
threatened species
Still abundant but numbers are dropping and
likely to become endangered
Causes of Depletion of Wild Species
- Human population growth
- Increasing per capita resource use
- Endangered centers of biodiversity
- Environmental destruction
- Spread of opportunistic species
causes of wild species depletion
- Human population growth
- Increasing per capita resource use
- Endangered centers of biodiversity
- Environmental destruction
- Spread of opportunistic species
importance of wild species
- Rebuilding biodiversity is
slow - Instrumental value
- Genetic information
- Eco-tourism
- Ecological value
- Intrinsic value
intrinsic value
they have value because they exist
greatest threat to species HIPPCO
Habitat destruction
Invasive species
Population (humans) growth
Pollution
Climate
Overharvesting
characteristics of successful invader species
high reproductive rate, generalist, pioneer species, high dispersal rate
characteristics ecosystems vulnerable to invader species
early successional systems, low diversity, similar climate to invader, no predators of invader
extinction threats
- Hunting and Poaching
- Predators and Pest
Control - Exotic Pets and
Decorative Plants - Climate Change and
Pollution
bioaccumulation
an increase in the concentration of a chemical in the tissue or organs at a higher level than normally expected
biomagnification
increase in the concentration of slowly degradable, fat-soluble chemicals in organisms successively higher trophic levels of a food chain or web
instrumental value
The value or worth of objects that provide a means to some desirable end, that satisfy some human needs and wants.
