Campbell Biology Ecology Unit

ecology

ecology

scientific study of interactions among organisms and between organisms and their environment

climate

The average weather conditions in an area over a long period of time

organismal ecology

The branch of ecology concerned with the morphological, physiological, and behavioral ways in which individual organisms meet the challenges posed by their biotic and abiotic environments

Population ecology

analyzes factors that affect population size and how and why it changes through time

Community ecology

examines how interactions between species, such as predation and competition, affect community structure and organization

Ecosystem ecology

emphasizes energy flow and chemical cycling between organisms and the environment

Landscape ecology

focuses on the factors controlling exchanges of energy, materials, and organisms across multiple ecosystems

Global ecology

how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere

macroclimate

patterns on the global, regional, and local level

microclimate

Very fine scale variations of climate, such as the specific climatic conditions underneath a log.

abiotic

nonliving, physical features of the environment, including air, water, sunlight, soil, temperature, and climate

biotic

the living organisms in an ecosystem

biomes

a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.

climograph

a plot of the temperature and precipitation in a particular region

ecotone

The transition from one type of habitat or ecosystem to another, such as the transition from a forest to a grassland.

canopy

dense covering formed by the leafy tops of tall rain forest trees

disturbance

A discrete event that disrupts an ecosystem or community. Examples of natural disturbances include fires, hurricanes, tornadoes, droughts, and floods. Examples of human-caused disturbances include deforestation, overgrazing, and plowing.

Tropical forests

sometimes called rainforests, are found close to the equator. Temperatures are warm and fairly constant throughout the year. Tropical forests receive between 200 and 400 centimeters of rain a year, distributed between a wet season and a dry season. Home to millions of animal species.

Deserts

Occur in bands near 30 degrees north and south of the equator and in the interior of the continents. Precipitation less than 30 cm per year. May be cold or warm. Plants are adapted for heat, water storage and reduced leaf surface area. urbanization and conversion have reduced the natural biodiversity.

Savanna

Equatorial and subequatorial regions. Precipitation is seasonal. Grasses amd forbs are the most of the ground cover. Plant species are fire adapted and tolerant to drought. Inhibitants are insects and mammals.

Chaparral

in midaltitude coastal regions on several continents. Precipitation highly seasonal. Summer is hot, the rest are cool. Dominant in shrubs, small trees, grasses and herbs. Animals include amphibians, birds, reptiles, insects, small mammals.

Temperate grassland

Found on many continents. Precipitation is highly seasonal. Winters are cold, summers are hot and wet. Dominant plants are grasses and forbs. Animals - large grazers (bison, horses), small burrowers. Most are converted to farmland.

Northern Coniferous forest

(taiga) largest terrestrial biome. Precipitation varies. Winters are cold, summers may be hot. Conifers (pine, fir) dominate. Animals are birds, large mammals (moose, brown bear, Siberian tigers). Some are logged at an alarmin rate.

Temperate broadleaf forest

at midaltitudes in the Northern Hemisphere, smaller areas in Chile, S. Africa, Australia and New Zealand. Rich in precipitation at all seasons. Winters avarage at 0, summers are hot and humid.Mammals, birds and insects live here.At some places the forest are being recovered.

Tundra

covers expansive areas of the Arctic, alpine tundra exists on high mountaintops at all latitudes. Precipitation low in arctic, higher in alpine tundra. Winters cold, summers cool.Vegetation herbaceous. - musk oxen, caribou, reindeer, bears, wolves, foxes. Became focus of oil and mineral extraction.

photic zone

regions of a body of water where light penetrates, enabling photosynthesis

aphotic zone

the part of the ocean beneath the photic zone, where light does not penetrate sufficiently for photosynthesis to occur.

pelagic zone

The open-ocean zone at the greatest depth in a marine habitat. This zone is divided into a photic (down to 600 feet below the water's surface) and aphotic zone.

abyssal zone

this zone is deep in the aphotic zone, roughly 2,000 - 6,000 meters deep.

benthic zone

bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms

benthos

The communities of organisms living in the benthic zone of an aquatic biome

detritus

Parts of dead organisms and cast-off fragments and wastes of living organisms.

thermocline

A narrow stratum of rapid temperature change in the ocean and in many temperate-zone lakes

turnover

the mixing of waters as a result of changing water-temperature profiles in a lake

Lakes

This aquatic biome is a standing body of water that can range from ponds, a few square meters in area, to lakes covering thousands of square kilometers. Light decreases with depth, creating stratification.

Oligotrophic lakes

nutrient poor and oxygen rich, with low amounts of decomposing matter

Eutrophic lakes

Lakes which are oxygen-poor and nutrient-rich, and have high amounts of organic matter

littoral zone

a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants

limnetic zone

This is the part of lake that is too far from shore to support rooted plants. It is made up of phytoplankton, including cyanobacteria.

zooplankton

Floating microscopic animals, including the larval stages of many larger animals. feed on phytoplankton and other zooplankton.

Wetlands

areas of standing water wet all or most of the year that support aquatic plants including marshes, swamps, and bogs. Species diversity is very high. Plants - lilies, cattails, sedges. Animals - birds, frogs, alligators. Humans detroyed up to 90%.

Streams and rivers

In this aquatic biome the most prominent physical characteristic is the current. A diversity of fishes and invertebrates inhabit this biome when it is unpolluted. Damming and flood control impair natural fluctuation of this biome's ecosystem.

headwaters

The water from which a river rises, source of water. Usually cold, clear, turbulent and oxygen rich

downstream

towards the mouth or final discharge of the water. Generally warmer, more turbid, more oxygenated.

Estuaries

a bay or drowned valley where a river empties into the sea. Salinity varies with the rise and fall of the tides. Nutrient-rich and highly productive. Include a complex network of tidal channels, islands, natural levees and mudflats. Saltmarsh grasses and algae are the major producers.

Intertidal zones

This aquatic biome is periodically submerge and exposed by the tides. The organisms that live her are challenged by variations in temperature and salinity and by the mechanical forces of wave action. When this biome is made up of rocky terrain, the animals that inhabit it generally have adaptations that enable them to attach to the hard substrate.

Oceanic pelagic zone

This aquatic biome is a vast realm of open blue water, constantly mixed by wind-driven oceanic currents. This biome covers approximately 70% of the Earth's surface. Phytoplankton and zooplankton are the dominant organisms in this biome; also found here are free swimming animals.

Coral reefs

This aquatic biome is formed from the calcium carbonate skeletons of corals (phylum Cnidaria). Corals require a solid substrate for attachment. Unicellular algae live within the tissues of the corals and form a mutualistic relationship that provides the corals with organic molecules.

marine benthic zone

Consists of the seafloor below the surface waters of the coastal zone or neritic zone and the offshore pelagic zone zone. Except for shallow, near-coastal areas, this aquatic biome receives no sunlight. Organisms in the very deep benthic zone receive no sunlight and are adapted to continuous cold and extremely high pressure. Oxygen is usually available are associated deep sea hydrothermal vents. obtain enrgy by oxidizing H2S by a reaction of hot water with Sulfate.

Dispersal

the movement of individuals or gametes away from their area of origin or from centers of high population density

population

a group of individuals of a single species living in the same general area, rely on the same sources and breed with one another, described by boundaries and size

density

number of individuals per unit of area or volume

dispersion

pattern of spacing among individuals within the boundaries of the population

mark-recapture method

estimate the size of wildlife populations by marking and releasing animals and then recapturing them

immigration

influx of new individuals from other areas (birth)

emigration

movement of individuals out of a population and into other locations (death)

clumped dispersion

individuals aggregated in patches, associated with better environmental conditions, mating behavior, increase effectiveness of defense

uniform dispersion

evenly spaced resulting from direct interactions between individuals

territoriality

result from uniform dispersion, defense of a bounded physical space

random dispersion

position independent of other individuals, no strong connections or repulsions

demography

study of the vital statistics of populations and how they change over time (death and birth rates)

life tables

age-specific summaries of the survival pattern of a population

cohort

group of individuals of the same age, from birth until all of the individuals are dead

Survivorship curve

plot of the proportion or numbers in a cohort still alive at each stage

Type I

flat at start, reflecting low death rates during early and middle life, drops steeply as death rates increase among older age groups (humans)

Type III

drops sharply at the beginning, but flattens out as death rates decline (fish)

Type II

constant death rate (squirrel)

reproductive rate

how reproductive output varies with the ages of females

reproductive table

age specific summary of the reproductive rates in a population, measures the reproductive output of a cohort from birth to death

reproductive output

product of the proportion of female offspring of those breeding females

Exponential population model

population growth in an ideal unlimited environment, J-shaped curve

per capita birth rate

number of offspring produced per unit of time by an average member of the population B=bn

per capita death rate

expected number of deaths per unit of time D=mn

zero population growth

balance of birth and death rates r=0

carrying capacity

(K), maximum population size that a particular environment can sustain

community

a group of populations of different species living close enough to interact

interspecific interactions

interactions among different species

competition

(-/-) two or more species compete for a resource that is in short supply

competitive exclusion

an outcome of slight reproductive advantage, leading to a local elimination of the inferior competitor

ecological niche

the sum of a species' use of the biotic and abiotic resources in its environment

resource partitioning

differentiation of niches that enables similar species to coexist in a community

character displacement

tendency for characteristics to diverge more in sympatric than in allopatric populations of two species

predation

(+/-) a predator kills and eats a prey; has led to diverse adaptations such as mimicry

cryptic coloration

a passive defense, camouflage against an organism's environment

aposematic coloration

warning coloration

Batesian mimicry

a harmless (palatable) species mimics a harmful (unpalatable) one

Mullerian mimicry

two or more harmful (palatable) species resemble each other

herbivory

(+/-) an organism eats part of a plant or alga

symbiosis

individuals of two or more species live in direct and intimate contact with one another

parasitism

(+/-) parasite derives nourishment from a host which is harmed

endoparasites

parasites that live within the body of their host

ectoparasites

parasites that feed on the external surface of a host

mutualism

(+/+) symbiosis in which both species benefit

obligate mutualism

mutualism in which at least one species can't survive without its partner

facultative mutualism

mutualism in which both species can survive alone

commensalism

(+/0) one species benefits from the interaction, the other is unaffected

facilitation

(+/+) or (+/0) one species has a positive effect on the survival and reproduction of another species without the intimate association of a symbiosis

species diversity

variety of different kinds of organisms that make up the community

species richness

number of different species in the community

relative abundance

the proportion a species represents of all individuals in the community