environmental chapter 15
loss of habitat is the greatest threat to biological diversity, followed by what
pollution, spread of invasive species, and overexploitation
what does ex situ (outside its place) conservation involve
preserving biodiversity in human-controlled settings such as zoos, botanical gardens, or seed banks of genetically diverse plant crops
Which of these disappeared during a mass extinction event, as opposed to being an accelerated background extinction?
t rex
Which of these most directly bans the global hunting, capture, and selling of endangered species and products of these species?
the 1975 Convention on International Trade in Endangered Species
what is habitat fragmentation
the breakup of large areas of habitat into small, isolated patches (islands) due to human use of land
what is extinction
the elimination of species from earth
what is genetic diversity
the genetic variation within all populations of a species
the maintenance of a broad genetic base is critical for what
the long-term health and survival of each species
what does the introduction of nonnative (invasive) species into a new ecosystem do
upsets the balance among the organisms living in that area and interferes with the ecosystem's normal functioning
what is the agricultural importance of organisms
we must eat to survive
Maintaining biological diversity in a coastal area can lead to increased
wildlife habitat
why are genetic resources of organisms important to the pharmaceutical industry
-AIDS medication AZT is a derivative of a compound extracted from a sponge -many of the best-selling prescription drugs in the us are natural products slightly modified, or synthetic chemicals derived from natural chemicals produced by organisms
what does the convention on international trade in endangered species of wild flora and fauna do
-bans the hunting, capturing, and selling of endangered and threatened species -protects more than 30,000 species -enforcement varies from country to country
how do humans alter habitats
-building roads, buildings, and bridges -clearing forests for agricultural use of land or timber -draining and filling wetlands for building -mining for minerals or fuel -recreational use of land
Biodiversity hotspots are relatively small tracts of land which are rich in endemic species. What is true of these hotspots
-by the year 2000, 25 hotspots had been identified worldwide -they are often found on islands -they were originally described using plants as the primary criteria
what shows that the activities of all organisms in an ecosystem are interrelated
-ecosystem services and species richness -when one species declines, other species linked to it may either decline or increase in number
what do conservation organizations fo
-educate policymakers, galvanize public support, provide financial support for projects -work in conjunction with zoos, aquaria, botanical gardens, etc -provide financial support for conservation projects
what is the national wildlife refuge system
-established in 1903 by teddy roosevelt -most extensive network of lands and waters committed to wildlife preservation in the world -covers over 60 million hectares -represents all major us ecosystems -administered by the us fish and wildlife service
how do invasive species cause species endangerment
-foreign species that spread rapidly in a new area if free of predators, parasites, or resource limitations that may have controlled their population in their native habitat -compete with native species for food and habitat
what causes threats to biological diversity
-growth of human populations -economic activity -uses of technology -social, political, and cultural factors
what are freshwater system ecosystem services
-moderate water flow and mitigate floods -dilute and remove pollutants -provide wildlife habitat -provide humans with water, food, transportation corridors, electricity, and recreation
what is true regarding ecosystem services
-natural products of organisms hold promise as medical therapies -a diverse natural world provides solace and comfort and serves as inspiration -diverse ecosystems provide more types of food
what are goals of the World Conservation Strategy
-preservation of ecosystem services -develop sustainable uses for organisms and ecosystem -preserve biological diversity
what are coastal ecosystem services
-provide a buffer against storms -dilute and remove pollutants -provide wildlife habitat, including food and shelter for young marine species -provide humans with food, harbors, transportation routes, and recreation
what are grassland ecosystem services
-purify air and water -produce and maintain soil -absorb carbon dioxide -provide wildlife habitat -provide humans with livestock and recreation
what are forest ecosystem services
-purify air and water -produce and maintain soil -absorb carbon dioxide -provide wildlife habitat
what are disadvantages to seed and gene banks
-some seeds cannot be stored -seeds must be germinated periodically so more can be collected, due to longevity issues -stored seeds are not continuously exposed to environment
how many reintroductions to the wild are successful
1 out of 10
how many new species are identified per year
10,000
how many plant and animal species were threatened with extinction in 2015
23,000
how many biological hotspots are there around the world
35
The U. S. Fish and Wildlife Service has estimated that since about the year 1800, more than ____________ U. S. species have become extinct.
500
what is a species
a group of distinct organisms that are capable of interbreeding with one another in the wild but that do not interbreed with organisms outside their group
what are endangered species
a species in imminent danger of extinction throughout all or a significant portion of its range
what are threatened species
a species whose population has declined to the point that it may be at risk of extinction
what is an ecotone
a transitional zone where communities meet
The Endangered Species Act could be made more comprehensive if it
addressed whole ecosystems rather than single species
what has the greatest footprint and widest ecological influence on natural ecosystems
agricultural use of land
Select the best description of extinction.
an organism has disappeared throughout its range
what type of areas tend to have lower species richness
areas with repeated disruptions to climate
what portion of the plant population has not been assessed for medicinal, agricultural, or industrial value
at least two thirds
what did the endangered species act do
authorized FWS and national marine fisheries service to protect endangered and threatened species in the us and abroad
Suppose a population is classified as an endangered species. If the species naturally recovers some numbers, it may
be re-classified as threatened
Which of these terms is a major heading that includes the other three as subcategories?
biological diversity
Which of these practices is an example of ex situ conservation?
captive breeding in zoos and research facilities
what is edge effect
change in species composition that occurs at ecotones
Which of these is associated with increased species richness, as per the graph below?
complexity of the physical environment
Most cases that involve conflict over the Endangered Species Act result in
compromise between developers and the federal government
what is the best way to preserve biodiversity
conserving and managing the ecosystem as a whole
what is background extinction
continuous low level of extinction of species, normal process
what has a disruptive effect on evolution
deforestation
what is overexploitation
deliberate effort to eradicate or control numbers of species
how many species were scientifically named and described as of 2015
more than 1.6 million
why are most species endangered today
destruction, fragmentation, or degradation of habitats due to human activities
many agricultural crops have been developed with significant genetic uniformity in order to optimize production. what can this lead to
disease and pest susceptibility
what may hold solutions to today's problems and to problems we have not begun to imagine
diversity
what do habitat corridors do
enable wild organisms to move from one fragmented area to another, essentially increasing their available habitat by safely connecting individual habitat fragments
A snow leopard was recently caught and killed in Afghanistan. As there are only a few thousand left in the wild, facing possible disappearance as a species, the snow leopard is best classified as
endangered
what does in situ (in place) conservation include
establishment of parks and reserves, concentrates on preserving biological diversity in nature
what has produced the genetic diversity that we see today
evolution
This ecosystem provides many ecosystem services, including purifying air and water, producing and maintaining soil, and absorbing and storing carbon dioxide (which can help to mitigate global warming).
forests
This ecosystem's services dilutes and removes pollutants from water, moderates water flow and reduces flooding, and supports many important human activities including transportation, food, and water.
freshwater systems
Which of these is the best example of an activity of a conservation biologist?
gathering data on the reintroduction of wolves to yellowstone national park
what are the three components of biodiversity
genetic diversity, species richness, and ecosystem diversity
what uses gene diversity
genetic engineering
What is the human activity that threatens most species facing extinction today?
habitat destruction
Where is declining biological diversity the most serious
hawaii
what has disrupted habitats
human population growth
how do pollution and climate change cause species endangerment
human produced acid precipitation, ozone depletion, climate change degrade even otherwise undisturbed wilderness habitats
why do humans need biodiversity
humans depend on thousands of species for survival
what does increased species richness do
improves ability of a community to withstand environmental disturbances
Suppose a local population is declining due to malnourishment. There has been no change in its overall food supply in the area. What is a possible cause?
invasive species
An endemic species
is native only to a particular region
what is mass extinction
large number of species disappear during a relatively short period of geologic time
what does the endangered species act do
legally defines what endangered and threatened species are
what type of climates have enabled a wide variety of species to evolve over time and form very biologically diverse communities
long-term stable climates
what heightens the risk of extinction
low genetic diversity
what are endemic species
native to an area
what do organisms provide for modern industrial technology
oils, lubricants, perfumes, fragrances, dyes, paper, lumber, waxes, and latex
what is the goal of captive breeding programs practiced by zoos and other conservation organizations
produce offspring that will be able to be released back into nature to restore wild populations
what are habitat corridors
protected zones that connect otherwise isolated, unlogged or undeveloped areas
what does restoration ecology do
reclaims disturbed lands and converts them into areas with high biodiversity, using ecological principles to return them to a functional and sustainable ecosystem
what are biological hotspots
relatively small areas of land that contain an exceptional number of endemic species and are at high risk from human activities
Species richness is defined as the number of _________ in a particular area.
species types
Which of these is the goal of restoration ecology practices?
returning an ecosystem to a historical state
why is species richness inversely related to isolation of community
species have difficulty reaching and colonizing isolated places and locally extinct species are not replaced quickly
what provides the community with resilience, the ability to recover quickly to its former state following an environmental disturbance
species richness
what is biodiversity
the number and variety of earth's organisms
what is species richness
the number of different species in a community
what is conservation biology
the scientific study of how humans affect organisms and how to develop methods to protect biological diversity
what is restoration ecology
the study of the historical condition of a human damaged ecosystem, with the goal of returning it as closely as possible to its former state
what is ecosystem diversity
the variety of ecosystems found on earth and the variety of interactions among organisms in natural communities
what is the relationship between species richness and environmental stress
they are inversely related