chapter 40: preserving biodiversity Flashcards
Is Earth’s biodiversity essential to our survival?
yes
biodiversity
the variety of life on Earth
is biodiversity inclining or declining?
declining
extinction
the last individual of a species has perished
endangered species
has a high risk of extinction in the future
vulnerable species
likely to become extinct in the more distant future
conservation biologist
study the preservation of biodiversity
main causes of the loss of biodiversity
habitat loss, pollution, global climate change, invasive species, and overexploitation
what is the primary threat to biodiversity?
habitat destruction
deforestation
the removal of trees
how much of the original temperate forest still remains in the United States?
1%
[blank] eliminates many habitats and negatively impacts nearby land and water resources
urbanization
are deserts expanding or contracting? Why?
expanding
Widespread drought and overgrazing by domesticated animals is turning large areas of tropical savanna into desert.
In dry areas like Arizona, humans manipulate water for recreation, agriculture, flood control, and to support cities.
pollution
any chemical, physical, or biological change in the environment that harms living organisms. Pollution degrades the quality of air, water, and land, threatening biodiversity worldwide
eutrophication
excessive nutrients ultimately lead to oxygen-poor water that cannot sustain much life
what do nutrients from sewage, fertilizers, and animal wastes cause algae to do?
bloom
the role of decomposers in eutrophication
carry out cellular respiration as they consume dead algae
depletes oxygen in the water
Nutrient runoff from much of the United States flows into the Mississippi River and triggers a large, seasonal [blank] in the Gulf of Mexico
dead zone
what happens in the dead zone in the Gulf of Mexico?
the seasonal lack of oxygen kills many animals, disrupting not only the Gulf’s food web but also its economy since fish and shrimp cannot live in oxygen-depleted water
persistent organic pollutants
carbon-containing molecules that do not degrade.
Many pesticides fall into this category, as do some pharmaceuticals and solvents
biomagnification
accounts for the high concentrations of toxic chemicals in the fatty tissues of tunas, polar bears, and other top predators
why does biomagnification happen?
Because they do not biodegrade, fat-soluble chemicals become more concentrated as they move up the food chain
smog
visible air pollution
particulates
tiny bits of matter that float in the air.
Ex. road dust volcanic ash, and soot from partially burned fossil fuels
why can suspended particulates cause inflammation, shortness of breath, asthma, or cancer
the heavy metals and toxic organic compounds
Burning fossil fuels releases [blank] and [blank] into the atmosphere, where they mix with [blank] and form [blank]
sulfur
nitrogen oxides
water
acids
acid deposition
acids fall back to Earth
[blank] is a gas that blocks UV radiation in the upper atmosphere
Ozone
human-made [blank] compounds damage ozone
chlorofluorocarbon (CFC)
where are CFC’s found
in Freon, aerosol cans, and foamed plastics
how did CFCs facilitate the breakdown of the ozone?
it persisted for decades in the upper atmosphere
the Montreal Protocol
an international treaty signed in 1987, banned the used of CFCs
how long do experts estimate the ozone layer to recover?
the mid-latitudes should recover by 2050, healing the hole over Antarctica might take some 25 years longer
why is global climate change a more accurate term than global warming?
some areas will become warmer and others will become cooler
greenhouse gases [blank] Earth’s surface
warm
greenhouse effect
an increase in surface temperature on Earth caused by heat-trapping gases in the atmosphere
Carbon dioxide and other greenhouse gases prevent heat from escaping Earth’s atmosphere (similar to how glass keeps heat from escaping a greenhouse)
have carbon dioxide and temperature been increasing or decreasing?
increasing
consequences of global climate change
polar ice sheets are melting and sea levels are rising, changing icy and aquatic ecosystems.
rising carbon dioxide concentration also directly affects oceans ecosystems
carbon dioxide causes ocean waters to become more acidic, threatening many organisms
invasive species
human transportation often brings other organisms along for the ride. Nonnative species spreads widely in its new habitat.
They displace native organisms
what is considered invasive?
an introduced species must begin breeding in its new location and spread widely from the original point of introduction
The species must harm the environment, human health, or the economy
how many invasive species are there in the united states?
500
overexploitation
harvesting a species faster than it can reproduce
examples of overexploitation
overhunting terrestrial species (for trade, sport, or food) and overharvesting maine organisms
[blank] animals sometimes get caught in nets meant for other species
nontarget
HIPPO
a useful acronym to remember the threats to biodiversity. Addressing these threats may help recover or prevent future loss of biodiversity
habitat destruction, invasive species, population, pollution, overexploitation
bald eagles have recovered since 1970, thanks to ….
the Endangered Species Act
awareness and government action can help save endangered species
what is the primary goal of conservation?
to preserve critical habitat
what is the secondary goal of conservation?
restoration, which seeks to reverse habitat destruction
ways conservationists seek to assist species in degraded habitats
by supplying wildlife corridors or building “fish ladders” over dams
ecotourism
provide financial incentive for conservation
in areas where wildlife poaching is a problem
how can biotechnology assist in conservation efforts
DNA preserved specimens might be useful in bringing back extinct species
researchers are using CRISPR-Cas 9 technology to add a disease-resistant gene to the American chestnut tree, which has been nearly eradicated by an invasive fungus
