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environmental science
exam 2
77
Environmental Studies
Undergraduate 3
03/09/2011

Additional Environmental Studies Flashcards

 


 

Cards

Term
biome
Definition
a large, relatively distinct terrestrial region with characteristic climate, soil, plants, and animals, regardless of where it occurs; a biome encompasses many interacting ecosystems. Near the poles, temperature is generally the overriding climate factor in determining biome distribution, whereas in temperate and tropical regions, precipitation is more significant.
Term
Tundra
Definition
is the treeless biome in the far north that consists of boggy plains covered by lichens and small plants such as mosses; it has harsh, very cold winters and extremely short summers.
Term
Boreal forest
Definition
is a region of coniferous forest in the Northern Hemisphere, located just south of the tundra.
Term
Temperate Rain Forest
Definition
is a coniferous biome with cool weather, dense fog, and high precipitation.
Term
Temperate Diciduous Forest
Definition
is a forest biome that occurs in temperate areas where annual precipitation ranges from about 75 cm to 126 cm
Term
Tropical Rain Forest
Definition
is a lush, species-rich forest biome that occurs where the climate is very moist throughout the year.
Term
Chaparral
Definition
 is a biome with mild, moist winters and hot, dry summers; vegetation is typically small-leafed evergreen shrubs and small trees.
Term
Temperate Grassland
Definition
is a grassland with hot summers, cold winters, and less rainfall than is found in the temperate deciduous forest biome.
Term
Savanna
Definition
is a tropical grassland with widely scattered trees or clumps of trees.
Term
Desert
Definition
is a biome in which the lack of precipitation limits plant growth; deserts are found in both temperate and tropical regions.
Term
important environmental factors in aquatic ecosystems
Definition

salinity, amount of dissolved oxygen, and availability of light for photosynthesis.

 

Term
Freshwater ecosystems include
Definition
standing-water, flowing-water, and freshwater wetlands (marshes and swamps).
Term
flowing water ecosystem
Definition
is a freshwater ecosystem such as a river or stream in which the water flows in a current.
Term

Standing water ecosystem

 

Definition
is a body of fresh water surrounded by land and whose water does not flow, such as a lake or pond
Term
Freshwater wetlands
Definition
are lands that shallow fresh water covers for at least part of the year; wetlands have a characteristic soil and water-tolerant vegetation.
Term
estuary
Definition
is a coastal body of water, partly surrounded by land, with access to the open ocean and a large supply of fresh water from a river. Water in an estuary is brackish rather than truly fresh. Temperate estuaries usually contain salt marshes, whereas tropical estuaries are lined with mangrove forests.
Term
Evolution
Definition

is the cumulative genetic changes in populations that occur during successive generations.

 

Term
Natural Selection
Definition
is the tendency of better-adapted individuals—those with a combination of genetic traits better suited to environmental conditions—to survive and reproduce, increasing their proportion in the population.
Term
Natural selection is based on four premises established by Charles Darwin:
Definition
(1) Each species produces more offspring than will survive to maturity. (2) The individuals in a population exhibit inheritable variation in their traits. (3) Organisms compete with one another for the resources needed to survive. (4) Those individuals with the most favorable combination of traits are most likely to survive and reproduce, passing their genetic traits to the next generation.
Term
ecological succession
Definition

is the process of community development over time, which involves species in one stage being replaced by different species.

 

Term
primary succession
Definition
is the change in species composition over time in an environment that was not previously inhabited by organisms; examples include bare rock surfaces, such as recently formed volcanic lava and rock scraped clean by glaciers.
Term
Secondary succession
Definition
is the change in species composition that takes place after some disturbance destroys the existing vegetation; soil is already present. Examples include abandoned farmland and open areas caused by forest fires.
Term
population ecology
Definition
is the branch of biology that deals with the number of individuals of a particular species found in an area and how and why those numbers change over time.
Term
growth rate (r)
Definition
) is the rate of change (increase or decrease) of a population's size, expressed in percent per year.
Term
growth rate is due to
Definition
birth rate (b) and the death rate (d): r = b - d.
Term
Emigration (e)
Definition
), the number of individuals leaving an area
Term
immigration (i)
Definition
the number of individuals entering an area, also affect a local population's growth rate.
Term
Biotic potential
Definition
is the maximum rate a population could increase under ideal conditions.
Term
Exponential population growth
Definition

is the accelerating population growth that occurs when optimal conditions allow a constant reproductive rate for limited periods.

 

 Eventually, the growth rate decreases to around zero or becomes negative because of environmental resistance,

Term
environmental resistance
Definition
unfavorable environmental conditions that prevent organisms from reproducing indefinitely at their biotic potential.
Term
carrying capacity (K)
Definition
is the largest population a particular environment can support sustainably (long-term), assuming there are no changes in that environment.
Term

Human Population Patterns

Definition
It took thousands of years for the human population to reach 1 billion (around 1800). Since then, the population has grown exponentially. The United Nations projects the population will reach 7 billion by 2013. Although our numbers continue to increase, the growth rate (r) has declined slightly over the past several years
Term
zero population growth
Definition
in which it remains the same size because the birth rate equals the death rate, toward the end of the twenty-first century
Term
Thomas Malthus
Definition
was a British economist who said that the human population increases faster than its food supply, resulting in famine, disease, and war. Malthus's ideas appear to be erroneous because the human population has grown from about 1 billion in his time to more than 6 billion today, and food production has generally kept pace with population. But Malthus may ultimately be proved correct because we don't know whether our increase in food production is sustainable.
Term
earth's carrying capacity dependent on..
Definition

Estimates of Earth's carrying capacity for humans vary widely depending on what assumptions are made about standard of living, resource consumption, technological innovations, and waste generation. In addition to natural environmental constraints, human choices and values determine Earth's carrying capacity for humans.

Term
Demographics
Definition
is the applied branch of sociology that deals with population statistics.
Term
 As a country becomes industrialized, it goes through a_________as it moves from relatively high birth and death rates to relatively low birth and death rates.
Definition
demographic transition
Term
infant mortality rate
Definition
is the number of infant deaths under age 1 per 1000 live births
Term
total fertility rate (TFR)
Definition
is the average number of children born to each woman.
Term
Replacement-level fertility
Definition
is the number of children a couple must produce to “replace” themselves
Term
 Age structure
Definition
is the number and proportion of people at each age in a population.
Term
 A country can have replacement-level fertility and still experience population growth if the largest percentage of the population is in the prereproductive years. In contrast to developing countries, highly developed countries have low infant mortality rates, low total fertility rates, and an age structure in which the largest percentage of the population isn't in the prereproductive years.
Definition
Term
Four factors are most responsible for high total fertility rates:
Definition
high infant and child mortality rates, the important economic and societal roles of children in some cultures, the low status of women in many societies, and a lack of health and family planning services. The single most important factor affecting high TFRs is the low status of women. The governments of many developing countries are trying to limit population growth.
Term

Education of women decreases the total fertility rate, in part by delaying the first childbirth. Education increases the likelihood women will know how to control their fertility. Education also increases women's career options, which provide ways of achieving status besides having babies.

Definition
Term
Urbanization
Definition
is the process whereby people move from rural areas to densely populated cities. In developing nations, most people live in rural settings, but their rates of urbanization are rapidly increasing.
Term
Rapid urbanization makes it difficult to provide city dwellers with basic services such as
Definition
housing, water, sewage, and transportation systems.
Term
Compact development
Definition
is the design of cities so that tall, multiple-unit residential buildings are close to shopping and jobs, and all are connected by public transportation.
Term
Malnutrition
Definition

is the impairment of health due to consuming too few or too many calories.

 

Term
Undernutrition
Definition

is a serious underconsumption of calories that leaves the body weakened and susceptible to disease.

 

Term
Overnutrition
Definition
is a serious overconsumption of calories that leaves the body susceptible to disease.
Term
Food insecurity
Definition
 a condition in which people live with chronic hunger and malnutrition, is exacerbated by population growth, environmental problems, and poverty.
Term
slash-and-burn agriculture
Definition
patches of tropical forests are cleared to plant crops.
Term
Nomadic herding
Definition
carried out on arid land, requires herders to move livestock continually to find food for them.
Term
Intercropping
Definition

involves growing a variety of plants simultaneously on the same field.

 

Term
Prime farmland
Definition
in the United States is being lost to urbanization and urban sprawl. Global declines in plant and animal varieties have led many countries to collect germplasm, any plant or animal material that may be used in breeding.
Term
Farmers and ranchers strive to increase yields in many ways, including administering
Definition
hormones and antibiotics to livestock.
Term
green revolution
Definition
introduced modern cultivation methods and high-yield crop varieties to Asia and Latin America. These methods require developing nations to import energy-intensive technologies and to face environmental problems caused by inorganic fertilizers and pesticides.
Term
Environmental problems caused by industrialized agriculture include
Definition
air pollution from the use of fossil fuels and pesticides, water pollution from untreated animal wastes and agricultural chemicals, pesticide-contaminated foods and soils, and increased resistance of pests to pesticides
Term
Land degradation
Definition
decreases the future ability of the land to support crops or livestock.
Term
Clearing grasslands and forests and draining wetlands to grow crops have resulted in
Definition
habitat fragmentation, the breakup of large areas of habitat into small, isolated patches.
Term
Sustainable agriculture
Definition
uses methods that maintain soil productivity and a healthy ecological balance while minimizing long-term impacts. Unlike industrialized agriculture, sustainable agriculture relies on beneficial biological processes and environmentally friendly chemicals.
Term
Genetic engineering
Definition
is the manipulation of genes to produce a particular trait
Term
Genetic engineering produces 
Definition
more productive livestock varieties, more nutritious crops, or crop plants resistant to pests, diseases, or drought.
Term
Concerns about genetic engineering include
Definition
its potential to produce harmful organisms and to trigger food allergies.
Term
pesticide
Definition
is any toxic chemical used to kill pests
Term
narrow-spectrum pesticide
Definition
kills only the intended organism and does not harm other species.
Term
Most pesticides are broad-spectrum pesticides
Definition
 which kill a variety of organisms, including beneficial ones, in addition to the target pest.
Term
Pesticides can effectively control disease-carrying organisms and crop pests.
Definition
 The abundance of pests in agriculture is partly due to the common practice of monoculture, the cultivation of only one type of plant over a large area.
Term
Pesticide use leads to several problems:
Definition
pests evolve genetic resistance, an inherited characteristic that decreases the effect of a given agent (like a pesticide) on an organism; ecosystem imbalances occur when pesticides affect species other than the intended pests; and pesticides exhibit persistence, degrading very slowly.
Term
Bioaccumulation
Definition
is the buildup of a persistent pesticide or other toxins in an organism's body.
Term
Biological magnification
Definition
is the increased concentration of toxins, such as certain pesticides, in the tissues of organisms at higher levels in food webs. Pesticides also show mobility, moving to places other than where they were applied.
Term
biological controls
Definition
which use naturally occurring disease organisms, parasites, or predators to control pests.
Term
Pheromones
Definition
natural substances produced by animals to stimulate a response in other members of the same species, are used to attract and trap pest species.
Term
Integrated pest management
Definition
 is a combination of pest control methods that, if used in the proper order and at the proper times, keep a pest population low enough to prevent substantial economic loss.
Term
Which are the crops on from which humans get 50% of all their calories
Definition
grain
Term
Why do strawberries turn red?
Definition
Because they absorb red yellow and orange light
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