Ecology - Sci Oly Div C

Abiotic

Non living (Water, wind, rocks)

Acid precipitation

Includes acid rain, acid fog, acid snow, and any other form of precipitation that is more acidic that normal (i.e., less that pH 5.6).

Adaptation

Any genetically controlled structural, physiological, or behavioral characteristic that helps an organism survive under a given set of environmental conditions

Aerobic

Living or occurring only in the presence of oxygen

Amensalism

Two organisms in a symbiotic relationship in which one is unaffected and one is harmed (the black walnut tree secretes juglone which kills the plants living at base of tree, but the lack of competition doesn't help or harm the tree). This is a very rare type of symbiosis.

Ammonification

The process by which decomposers change nitrogen in detritus to ammonium (NH4+)

Anaerobic (adj.)

Lacking or seriously depleted of oxygen

Assimilation

The process by which plants absorb nitrate or ammonium through root hairs to be used within the plant

Autotroph

Organism that uses solar or chemical energy to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment (think producers)

Batesian Mimicry

Resemblance of an unpalatable species by an edible species to deceive predators

Biodiversity

Variety of different species (species diversity), genetic variability among individuals within a species (genetic diversity), variety of ecosystems (ecological diversity), and functions such as energy flow and matter cycling needed for the survival of a species and biological communities

Biomass

Organic matter produced by plants and other photosynthetic producers

Biome

Terrestrial regions inhabited by certain types of life, certain climate and vegetation

Biosphere

Zone of earth where life is found. It consists of parts of the atmosphere (the troposphere), hydrosphere (mostly surface and ground water), and lithosphere (mostly soil and surface rocks and sediments on the bottoms of oceans and other bodies of water) where life is found.

Biotic

Living or once living organisms. (Bunny, Dead Bunny)

Biotic potential

Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth

Carbon Cycle

Cyclic movement of carbon in different chemical forms from the environment to organisms then back to the environment

Carrying Capacity

The maximum number of organisms that an environment can support

Chemosynthesis

Process in which certain organisms (mostly specialized bacteria) extract inorganic compounds from their environment and convert them into organic nutrient compounds without the presence of sunlight

Climax community

Fairly stable, self-sustaining community in an advanced stage of ecological succession

Clumped Distribution

The most common type of population distribution where many members of the population live close together

Cohort

A group of individuals born around the same time

Commensalism

An interaction between organisms of different species in which one type of organism benefits and the other is neither helped nor harmed to any great degree

Community

Populations of all species living and interacting in an area at a particular time

Competition

Two or more individual organisms of a single species (intraspecific competition) or two or more individuals of different species (interspecific competition) attempting to use the same scarce resources in the same ecosystem

Consumer

Organism that cannot synthesize the organic nutrients it needs and gets its organic nutrients by feeding off of the tissues of producers or of other consumers

Decomposer

Organism that digests parts of dead organisms and cast-off fragments and wastes of living organisms by breaking down the complex organic molecules in those materials into simpler inorganic compounds and then absorbing the soluble nutrients

Deforestation

Removal of trees from a forested area without adequate replanting

Denitrification

The reduction of nitrates back into nitrogen gas (N2), completing the nitrogen cycle. This process is performed by bacterial species such as Pseudomonas and Clostridium in anaerobic conditions.

Desert

Biome in which evaporation exceeds precipitation and the average amount of precipitation is less than 25 centimeters a year. Such areas have little vegetation or have widely spaced, mostly low vegetation.

Desertification

Conversion of rangeland, rain-fed cropland, or irrigated cropland to desert-like land, with a drop of agricultural productivity of 10% or more

Detritivore

Consumer organism that feeds on detritus, parts of dead organisms, and cast-off fragments and wastes of living organisms

Detritus

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

Distribution

Area over which we can find a species

Ecology

Study of the interactions of living organisms with one another and with their nonliving environment of matter and energy, study of the structure and functions of nature

Ecosystem

Community of different species interacting with one another and with the chemical and physical factors making up its nonliving environment

Environment

All external conditions and factors, living and nonliving, that affect an organism or other specified system during its lifetime

Exponential growth

Growth in which some quantity, such as population size or economic output, increases at a constant rate per unit of time

Extant

A species that is still alive and reproducing

Extinct

A species that is no longer living on earth

Food chain

Series of organisms in which each eats or decomposes the preceding one

Food web

Complex network of many interconnected food chains and feeding relationships

Gene pool

The sum total of all the genes that exist among all the individuals of a species

Global warming

Warming of the earth's atmosphere because of increases in the concentrations of one or more greenhouse gasses primarily as a result of human activities

Grassland

Biome found in regions where moderate annual average precipitation (25-76 cm) is enough to support the growth of grass and small plants but not enough to support large stands of trees

Greenhouse effect

A natural effect that releases heat in the atmosphere near the earth's surface. Water vapor, carbon dioxide, ozone, and several other gasses in the lower atmosphere absorb some of the infrared radiation radiated by the earth's surface. This will eventually increase the temperature of the earth if there are enough of the greenhouse gasses

Gross primary productivity

The rate at which an ecosystem's producers capture and store a given amount of chemical energy as biomass in a given length of time

Habitat

Place or type of place where an organism or population of organisms lives

Herbivore

Plant-eating organism

Heterotroph

Organism that cannot synthesize the organic nutrients it needs and gets its organic nutrients by feeding off of the tissues of producers or of other consumers

Indicator Species

A species that gives an early warning that an ecosystem is in a state of flux, often times fish and amphibians or apex predators

Interspecific competition

Attempts by two or more species to use the same resources in an ecosystem

Intraspecific competition

Attempts by two or more organisms of a single species to use the same limited resources in an ecosystem

J-shaped curve

Curve with a shape similar to that of the letter J

Keystone species

Species that play roles affecting many other organisms in an ecosystem

K-selected species

Species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age

Limiting factor

Single factor that limits the growth, abundance, or distribution of the population of a species in an ecosystem

Muellerian Mimicry

Resemblance of two equally unpalatable species in order to increase the concentration of individuals with the warning appearance to increase its efficiency

Muskeg

An acidic soil type common in Arctic and boreal areas, more-or-less synonymous with bogland

Mutualism

A symbiotic relationship in which both participate species generally benefit

Niche

Total way of life or role of a species in an ecosystem. It includes all physical, chemical, and biological conditions a species needs to live and reproduce in an ecosystem

Nitrification

The process of oxidizing ammonia to create nitrite (NO2−)then oxidizing the nitrite to create nitrate (NO3-)

Nitrogen Cycle

Cyclistic movement of nitrogen in different chemical forms from the environment to organisms and then back to the environment

Nitrogen fixation

The process of chemically converting nitrogen gas (N 2 ) from the air into compounds, such as nitrates (NO 3 ), nitrites (NO 2 ), or ammonia (NH 3 ), that can be used by plants in building amino acids and other nitrogen-containing organic molecules.

Nutrient

Any food or element an organism must take in to live, grow, or reproduce

Omnivore

Animal that can use both plants and animals as a food source

Organism

Any form of life

Parasitism

Interaction between species in which one organism, called the parasite, preys on another organism, the host

Perennial Herbaceous

A perennial plant that has stems that die at the end of the growing season, but parts of the plant survive under or close to the ground from season to season (for biennials, until the next growing season, when they flower and die). New growth develops from living tissues remaining on or under the ground, including roots, a caudex (a thickened portion of the stem at ground level) or various types of underground stems, such as bulbs, corms, stolons, rhizomes and tubers.

Phosphorus Cycle

Involves the uptake of phosphorus by organisms. Phosphorus in the environment is mainly found in rocks, and natural weathering processes can make it available to biological systems. Phosphorus is an essential nutrient for plants and animals in the form of ions PO43- and HPO42- . It is a part of DNA-molecules and RNA-molecules, molecules that store energy (ATP and ADP) and of fats of cell membranes.

Pioneer community

First integrated set of plants, animals, and decomposers found in an area undergoing primary ecological succession

Population

Group of individual organisms of the same species living in a particular area

Predation

A symbiotic relationship in which an organism kills another organism

Primary consumer

Organism that feeds on all or part of plants or on other producers

Primary succession

Ecological succession in a bare area that has never been occupied by a community of organisms

Producer

Organism that uses solar or chemical energy to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment

r-selected species

Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period

Rhizobia

Soil bacteria that fix nitrogen after becoming established inside root nodules of legumes

Scavenger

Organism that feeds on dead organisms that were killed by other organisms or died naturally

Second law of thermodynamics

In any conversion of heat energy to useful work, some of the initial energy input is always degraded to lower quality, more dispersed, less useful energy

Secondary Consumer

An organism that consumes a primary consumer

Secondary succession

Ecological succession in an area in which natural vegetation has been removed or destroyed but the soil is not destroyed

Species diversity

Number of different species and their relative abundances in a given area

S-shaped curve

Leveling off of an exponential, J-shaped curve when a rapidly growing population exceeds the carrying capacity of its environment and ceases to grow

Sustainability

Ability of a system to survive for some specified time

Symbiosis

Any intimate relationship or association between members of two or more species

Symbiotic relationship

Species interaction in which two kinds of organisms live together in an intimate association. Members of the participating species may be harmed by, benefit from, or be unaffected by the interaction

Synergy

Is the term used to describe a situation where the final outcome of a system is greater than the sum of its parts.

Taiga

The largest land biome. Characterized by conifer forests and cold temperatures. Boreal forest is usually used to refer to the more southerly part of the biome.

Tertiary Consumer

An organism that consumes a secondary consumer.

Trophic level

All organisms that are the same number of energy transfers away from the original source of energy that enters the ecosystem

Uniform Distribution

A rare type of population distribution where the population is evenly spread out

Zero population growth designates

a near balance of births and deaths

Population growth may be represented mathematically as

G = rN where G = population growth
per unit time, r = rate of increase, and N= the number of individuals

As long as per capita birth rates remain even slightly above per capita death rates then

a population will grow exponentially - with ever-increasing rates and shortened "doubling times"

It took 2 million years for the world's human population to reach 1 billion, yet

it took only 12 years to reach the fifth billion

If a population lives under ideal conditions, it may display its

biotic potential

Few populations live under ideal conditions because

a number of factors limit their growth

Logistic growth

Early on populations will exhibit very rapid growth, but as they near the carrying capacity, they will level off. This type of growth produces an S-shaped curve

Logistic growth is dependent on

density i.e., the growth is affected by the density of individuals.