ecology2 Flashcards
field of biology that studies methods and implements plans to protect diodiversity.
conservation biology
number of organisms of one species that an environment can support indefinitely; populations below carrying capacity tend to increase; those above carrying capacity tend to decrease.
carrying capacity
simple model that shows how matter and energy move through an ecosystem.
food chain
a community made up of interacting populations in a certain area at a certain time.
biological community
a stable, mature community that undergoes little or no change in species over time.
climax community
natural strips of land that allow the migration of organisms from one wilderness area to another.
habitat corridors
damage to a habitat by air, water, and land pollution.
habitat degradation
different environmental conditions that occur along the boundaries of an ecosystem.
edge effect
any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.
limiting factor
all the living organisms that inhabit an environment.
biotic factors
nonliving parts of an organism’s environment, air currents, temperature, moisture, light, and soil are examples.
abiotic factors
separation of wilderness areas from each other; may cause problems for organisms that need large areas for food or mating.
habitat fragmentation
growth pattern where a population grows faster as it increases in size; graph of a exponentially growing population resembles a J-shaped curve.
exponential growth phase
layer of the atmosphere that helps to protect living organisms on Earth’s surface from damaging doses of ultraviolet radiation from the sun.
ozone layer
organism that represents a feeding step in the movement of energy and materials through an ecosystem.
trophic level
rain, snow, sleet, or fog with a pH below 7; causes the deterioration of forests, lakes, statures, and buildings.
acid precipitation
programs that release organisms into an area where their species once lived in hopes of reestablishing naturally reproducing populations.
reintroduction programs
biome near the equator with warm temperatures, wet weather, and lush plant growth; receives at least 200 cm of rain annuall; contains more species of organisms than any other biome.
tropical rain forest
number of deaths per 1000 population in a given year.
death rate
a species in which the number of individuals falls so low that extinction is possible.
endangered species
nonnative species in an area; may take over niches of native species in an aera and eventually replace them.
exotic species
when the population of a species is likely to become endangered.
threatened species
proportions of a population that are at different age levels.
age structure
colonization of barren land by pioneer organisms.
primary succession
sequence of changes that take place after a community is disrupted by natural disasters or human actions.
secondary succession
time needed for a population to double in size.
doubling time
philosophy that promotes letting people use resources in wilderness areas in ways that will not damage the ecosystem.
sustainable use
model that shows all the possible feeding relationships at each trophic level in a community.
food web
deep water that never receives sunlight.
aphotic zone
portion of the marine biome that is shallow enough for sunlight to penetrate.
photic zone
portion of the shoreline that lies between high tide and low tide lines.
intertidal zone
a symbiotic relationship in which both species benefit.
mutualism
animals that feed on animals that have already died.
scavengers
arid region with sparse to almost nonexistent plant life; the driest biome, usually receives less than 25 cm of precipitation annually.
desert
biome composed of large communities covered with rich soil, grasses, and similar small plants; receives 25-27 cm of precipitation annually.
grasslands
biome just south of the tundra; characterized by a boreal or northern coniferous forest composed of larcli, fir, hemlock, and spruce trees and acidic, mineral-poor topsoils.
taiga
biome that surrounds the north and south poles; treeless land with long summer days and short periods of winter sunlight; characterized by permafrost.
tundra
coastal body of water, partially surrounded by land, which freshwater and salt water mix.
estuary
collection of several interacting populations that inhabit a common environment.
community
limiting factors such as disease, parasites, or food availability that affect growth of a population.
density-dependent factors
factor such as temperature, storms, floods, drought, or habitat disruption that affects all populations, regardless of their density.
density-independent factor
group of ecosystems with the same climax communities; biomes on land are called terrestrial biomes, those in water are called aquatic biomes.
biome
group of organisms all of the same species, which interbreed and live in the same place at the same time.
population
interactions among populations in a community; the community’s physical surroundings, or abiotic factors.
ecosystem
layer of permanently frozen ground that lies underneath the topsoil of the tundra.
permafrost
an organism’s patterno reproduction; may be rapid or slow.
life-history patterns
movement of individuals form a population.
emigration
movement of individuals into a population.
immigration
number of live births per 1000 population in a given year.
birthrate
orderly, natural changes, and species replacements that take place in communities of an ecosystem over time.
succession
organisms that cannot make their own food and must feed on other organisms for energy and nutrients.
heterotrophs
organisms that use energy from the sun or energy stored in chemical compounds to manufacture their own nutrients.
autotrophs
organisms, such as fungi and bacteria, that break down and absorb nutrients from dead organisms.
decomposers
permanent, close association between two or more organisms of different species.
symbiosis
place where an organism lives out its life.
habitat
portion of Earth that supports life; extends from high in the atmosphere to the bottom of the oceans.
biosphere
role or position a species has in its environment; includes all biotic and abiotic interactions as an animal meets its needs for survival and reproduction.
niche
scientific study of interactions between organisms and their environments.
ecology
small organisms that drift and float in the waters of the photic zone; includes both autotrophic and heterotrophic organisms, their eggs, and the juvenile stages of many marine animals.
plankton
study of population characteristics such as growth rate, age structure, and geographic distribution.
demography
symbiotic relationship in which one organism benefits at the expense of another, usually another species.
parasitism
symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited.
commensalism
biome composed of forests of broad-leaved hardwood trees that lose their foliage annually; receives 70-150 cm of precipitation annually.
temperate-deciduous forests
the ability of an organism to withstand fluctuations in biotic and abiotic environmental factors.
tolerance
the disappearance of a species when the last of its members dies.
extinction
the total mass or weight of all living matter in a given area.
biomass
variety of life in an area; usually measured as the number of species that live in an area.
biodiversity
when members of a species are held by people in zoos or other conservation facilities.
captivity
