chapter 56 Flashcards
what is conservation biology?
study of nature with the aim of protecting species habitats and ecosystems and to conserve biological diversity at all levels
what are the three components of biodiversity?
genetic, species, and ecosystem diversity
what is genetic diversity?
individual genetic variation within a population and between populations
what is an endangered species?
species on the verge of extinction
what is a threatened species?
species getting close to being endangered
is it good for a species to be highly adapted?
no because when conditions change, their specialization isn’t effective and they’ll die
broader range of diversity is _____
better
what is ecosystem diversity?
the variety of ecosystems in the biosphere
whats up with the flying fox bat?
its an important pollenator, many plants NEED it
what is background rate?
rate before human involvement, purely environmental
what is current rate?
what’s going on now
are we currently going through an extinction period?
yes, the 6th great extinction
what is the late ordovician extinction?
glaciers formed, sucking water to make glaciers-> oceans were compact and went extinct
what is the late devonian extinction?
unknown cause, shallow water creatures affected
what is the permian-triassic extinction?
first time insects were affected, many causes, “the great dying”
what is the late triassic extinction?
affected terristrial organisms, allowed dinosaurs to be dominant, volcanic eruption caused a dark sky->no plants
what is the cretaceous-tertiary extinction?
dinosaurs went extinct, asteroid in mexico
what rate does the rate of extinction look similar to?
rate the human population
what is ecosystem services?
encompasses all the processes through which natural ecosystems and their species help sustain human life
what are some examples of ecosystem services?
purification of air and water-plats filter feeders
detoxification and decomposition of wastes=bioremediation detritivores
cycling of nutrients=all organisms
moderation of weather extremes
why cant we predict extinctions?
we dont know the # of species, hard to confirm if a species is really extinct
what are the 4 major threats to biodiversity?
- agriculture, urban development, mining, pollution
- fishing
- competition
- climate change
why are specialists and species with small populations more at risk?
they need specific prey and when that prey goes extinct so do they
what are introduced species?
species that humans move from native locations to new geographic regions, disrupt local ecology
what is the best way to control invasive species?
prevent introduction, hard to control once started, don’t fully understand the effects of combatants
whats up with black rats?
first invasive species, spread with roman conquest, brings many diseases, creates competition with native species
control: rat poison
whats up with the brown tree snake?
arrived in guam as a stowaway, caused EXTINCTION of birds and lizards
control: aspirin-laced mice
whats up with the zebra mussel?
introduced in ballast water, competed with native species, clogged waterways
control: liquid fertilizer
whats whats up with the asian tiger mosquito?
spread through tires, carries diseases, eggs survive winter
control: insecticides
whats up with the burmese python?
escaped breeding facility, feed on endangered species
control: removal by hand (ineffective)
whats up with fire ants?
introduced by shipping crates, disrupts local ecology
control: insecticides
whats up with kudzu?
brought to slow soil erosion, grows really fast, outcompetes, changes leaf litter and soil composition
control: root crown removal, mowing, fire, grazing
whats up with mongoose?
brought to control rats, prey on native species (mongoose are diurl while rats are nocturnal)
control: traps and poison
whats overharvesting?
human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound
whos most at risk (r or k species?)
k species because they dont have as many offspring
what causes acid rain?
burning of wood and fossil fuels
what do forests contribute?
wildlife, recreation, oxygen
can extinct species be resurrected?
No, theres no genetic diversity, DNA degrades over time, their habitat is gone
they can bring back individuals but not an entire species
what is the small population approach?
small populations are especially vulnerable to extinction purely because of their small size
what is the declining population approach?
populations with a rapidly declining rate regardless of size
what is an extinction vortex?
A downward population spiral in which inbreeding and genetic drift combine to cause a small population to shrink and, unless the spiral is reversed, become extinct.
what drives an extinction vortex?
lack of genetic diversity
whats up with the northern elephant seal?
were severely hunted -> low genetic variation but not affected -> ideal environment-> escaped extinction
what is the minimum viable population? (mvp)
smallest population size that can still survive
what does mvp depend on?
food, predators, environment
why do we need to know the effective population size?
to know what the breeding potential is, to see how much offspring will be made
what is an edge or boundary?
the edge between ecosystems that has its own set of physical conditions that differ on each side
whats up with brown -headed cowbirds?
they lay their eggs in another birds nest and because it has a bigger beak, it takes the food that the mom gives them.
increase in cowbirds, decrease in other birds
what is a movement or wildlife corridor?
a narrow strip of habitat connecting otherwise isolated patches
what is a biodiversity hot spot?
relatively small area with numerous endemic species (species found nowhere else in the world) and a large number of endangered and threatened species
why are biodiversity hot spots hard to identify?
migration
biodiversity hot spots can change with ____ _____
climate change
are few large reserves or more small ones better?
few large ones because small ones don’t hold mvp, large but low-density animals like bears need large spaces, less affected by edge effects
what is a zoned reserve?
extensive region that includes areas relatively undisturbed by humans surrounded by areas that have been changed by human activity and are used for economic gain
whats with costa rica’s zoned reserves?
reduced costa rica’s international debt by preserving land
how can ecotourism help?
people can make money off of ecotourism instead of fishing, people are more likely to visit exotic places
do zoos help?
theres not enough space to bring every endangered animal to mate, plus they cant release it into the wild
what are some human-made changes in the environment?
nutrient enrichment
accumulation of toxins
climate change
ozone depletion
what is nutrient enrichment?
human activity often removes nutrients from one part of the biosphere and adds them to another
what is eutrophication?
nutrient runoff
what is critical load?
max nutrients a plant can absorb without run off
what is biomagnification?
toxins get magnified when you move up the food chain
what is DDT?
an insecticide; interferes with calcium so birds crush their eggs when they sit on them
what does fat have to do with PCBs?
it accumulates in fat tissue
what are dioxins?
very toxic; formed in industrial processes
what are PBDEs?
reduce flammability or things; found EVERYWHERE
what do pollen and fossil plant records reveal?
past vegetation
what do bubbles trapped in glacial ice reveal?
CO2 levels
what do chemical isotopes reveal?
past temperature
what is assisted migration?
translocate species into a favorable nonnative habitat
what is a solution to the energy problem?
reduce use and use renewable energy
what is a solution to the CO2 problem?
international effort required to reduce
what is the purpose of the ozone layer?
life on earth is protected from damaging effects of UV radiation
how is an ozone hole created?
produced by humans from aerosol spray and refrigerants
whats the problem with pharmaceutical drugs?
humans excrete residual chemicals or throw them in the toilet and ends up in bodies of water
whats the deal with government subsides?
they give money to farmers to grow specific crops but most of it gets wasted
how many wildfires are caused by humans?
84%
how much area do human fires cover?
44%
