Chapter 55 Flashcards
The excessive harvesting of an animal or plant species, potentially leading to its extinction
overexploitation
human-induced changes in the pathways through which water moves in the hydrologic cycle
hydrologic alternations
What factors have increased the likelihood of desertificaiton in southern Florida?
The growing human population in south Florida has increased the likelihood of desertification there by withdrawing groundwater for agricultural, recreational, and residential uses faster than it is replenished
What are the consequences of the overexploitation of fish populations?
overexploitation of fish populations typically causes fishes to reach reproductive maturity at a smaller size and younger age, decreases population sizes, and sometimes leads to the extinction of populations
How does the construction of a dam disrupt the lives of river dwelling oranisms
The construction of dams changes the water flow in rivers, leading to changes int eh physical structure of the river and the species that inhabit it; disrupting the environmental cues that trigger successful reproduction of organisms; inhibiting the free movement of migrating animals through all parts of the river system; and opening the habitat to invasion by species that originated elsewhere
A process in which remaining areas of intact habitat are reduced to small, isolated patches
habitat fragmentation
a phenomenon in which the removal of natural vegetation disrupts the local physical environment, exposing the borders of the remaining habitat to additional sunlight, wind, and rainfall
edge effects
materials or energy in a form or quantity that organisms do not usually encounter
pollutants
rainfall with low pH, primarily created when gaseous sulfur dioxide (SO2) dissolves in water vapor in the atmosphere forming sulfuric acid
acid precipitation
A nonnative organism
exotic species
How has habitat fragmentation affected breeding songbird populations in eastern North America?
Habitat fragmentation in eastern North America has affected breeding songbirds by reducing the variety of habitats available to them, increasing the frequency of brood parasitism of their nests, and increasing the rate of predation on their eggs and young
What environmental factor has caused the demise of vulture populations throughout South Asia?
the use of the anti-inflammatory drug diclofenac on livestock has decimated vulture populations in South Asia. Diclofenac is highly toxic birds, and the vultures ingest it when they feed on the carcasses of livestock
How do extinction rates today compare with the background extinction rate evident in the fossil record?
By 1 estimate, extinction rates today may be 1,000 times greater than the background extinction rate evident in the fossil record
The ecological processes on which all life depends, which include decomposition of wastes, nutrient recycling, oxygen production, maintenance of fertile topsoil, and air and water purificaiton
ecosystem services
How does biodiversity serve as a storehouse of genetic information that is potentially useful to humans?
Living systems are a storehouse of potentially useful genetic information because naturally occurring compounds may prove to be useful in the treatment of disease in the manufacture of new products, or in agriculture
What ecosystem services do naturally occurring organisms provide to humans?
naturally occurring organisms provide many ecosystem services, such as the sequestration of carbon dioxide, fixation of nitrogen into forms that plants can absorb, recycling of nutrients with ecosystems, and the retention of water in ecosystems
an area where biodiversity is both highly concentrated and endangered
biodiversity hotspots
A species in danger of extinction throughout all or a significant portion of its range
endangered species
What criteria do conservation biologists use to identify sites where extinctions are imminent?
conservation biologists identity a site as one where extinction is imminent if it houses 95% or more of the individuals in an endangered species and it has definable boundaries that encompass distinctive habitats
Why are conservation biologists especially concerned about the rapid rate of deforestation in the New World tropics?
Conservation biologists are especially alarmed about deforestation in the New World tropics because these forests harbor many species in imminent danger of becoming extinct
An interdisciplinary science that focuses on the maintenance and preservation of biodiversity
conservation biology
a mathematical analysis used by conservation biologists to determine the minimum viable population size for threatened or endangered species
population viability analysis
The smallest population size that is likely to survive both predictable and unpredictable environmental variation
minimum viable population size
The field that examines how large-scale ecological factors-such as the distribution of plants, topography, and human activity- influence local populations and communities
landscape ecology
How does a population bottleneck increase the likelihood that a species will become extinct?
population bottlenecks- large, temporary reductions in a population’s size- inevitably foster genetic drift, thereby reducing a population’s genetic variability which increases its likelihood of becoming extinct
How does a population viability analysis assist in the development of a conservation plan for a species?
a population viability analysis allows a conservation biologist to identify the minimum population size that is likely to survive both predictable and unpredictable environmental change. It therefore specifies how many individuals must be conserved for the continued survival of the population and species
Would a single large nature preserve or several small preserves experience greater edge effects?
Several small preserves would collectively experience more edge effect than one large preserve of the same total size
An activity in which visitors often from wealthy countries pay a fee to visit a nature preserve
ecotourism
A process in which ecosystem services are assigned an economic value
ecosystem valuation
Is the Pine Bush habitat in New York an example of preservation mixed-use conservation, or restoration?
The Pine Bush habitat in the state of New York is an example of conservation through preservation
How has the establishment of the Royal Chitwan National Park in Nepal been a successful conservation effort? How do conservation biologists measure its success?
The Royal Chitwan National park has been judged a success because local residents benefit form the park’s existence and therefore tigersand rhinoceroses, have increased within its borders
How can the concept of ecosystem services be used to foster conservation of threatened habitats and species?
Economists can determine the economic values of specific ecosystem services and convince local governments that it is economically beneficial to preserve ecosystems and the services they provide
A process in which large tracts of subtropical forests are cleared and overused, the groundwater table recedes to deeper levels, less surface water is available for plants, soil accumulates high concentrations of salts, and topsoil is eroded by wind and water
desertification
