Ecology Exam 1

The study of the natural environment and of the relations of organisms to each other and to their surroundings.

A living being; the most fundamental unit of ecology.

All the interacting parts of the physical and biological worlds.

The group of organisms of a particular species that inhabit a particular area.

An association of interacting populations, usually defined by the nature of their interaction or the place in which they live.

An intimate and often obligatory association of two species, usually involving coevolution. Symbiotic relationships can be parasitic or mutualistic.

The place where an animal or plant normally lives, often characterized by a dominant plant form or physical characteristic (that is, a stream habitat, a forest habitat).

The ecological role of a species in the community; the ranges of many conditions and resource qualities within which the organism or species persists, often conceived as a multi-dimensional space.

The dimension in time or space over which variation is perceived.

Change in the heritable traits of organisms through the replacement of genotypes within a population.

A genetically determined characteristic that enhances the ability of an individual to cope with its environment; the evolutionary process by which organisms become better suited to their environments.

Change in the frequency of genetic traits in a population through differential survival and reproduction of individuals bearing those traits.

A conjecture about or explanation for a pattern or relationship embracing a mechanism for its occurrence.

A logical consequence of a hypothesis or outcome of a model describing some aspect of a system.

A controlled manipulation of a system to determine the effect of a change in one or more factors.

A treatment that reproduces all aspects of an experiment except the variable of interest.

A small, simplified system, often maintained in a laboratory, that contains the essential features of a larger natural system.

The concentration of hydrogen ions in a solution, often written on the logarithmic scale of pH.

Removal of one or more electrons from an atom, ion, or molecule.

Addition of one or more electrons to an atom, ion, or molecule.

An organism that uses organic materials as a source of energy and nutrients.

Incorporation of any material into the tissues, cells, and fluids of an organism.

An organism that assimilates energy from either sunlight (green plants) or inorganic compounds (sulfur bacteria).

Use of the energy of light to combine carbon dioxide and water into simple sugars.

Use of oxygen to break down organic compounds metabolically to release chemical oxygen.

A layer of still or slow-moving water or air close to the surface of an object.

Without oxygen

Lacking oxygen; anaerobic

Electromagnetic radiation having a wavelength shorter than about 400 nm.

The warming of the earth's climate because of the increased concentration of carbon dioxide and certain other pollutants in the atmosphere.

The surface layer of water to the depth of light penetration at which photosynthesis balances respiration.

Light intensity,expressed in energy per unit of area per unit of time.

The intensity of solar radiation reaching the outer limit of the earth's atmosphere, approximately 1,400 W per meter squared.

Energy emitted in the form of electromagnetic waves.

The ability of heat to pass through a substance.

Transfer of heat by the movement of a fluid (for example, air or water).

The transformation of water from the liquid to the gaseous phase with the input of heat energy.

Evaporation of water from leaves and other parts of plants.

All the gains and losses of heat by an organism, including metabolism, evaporation, radiation, conduction, and convection.

The force by which water is held in the soil by capillary and hygroscopic attraction.

Referring to the water potential generated by soil.

The amount of water that soil can hold against the pull of gravity.

The minimum water content of the soil at which plants can obtain water.

Diffusion of substances in aqueous solution across the membrane of a cell.

The attraction of water to an aqueous solution owing to its concentration of ions and other small molecules; usually expressed as a pressure.

Referring to a membrane that blocks the passage of some molecules, usually large ones, but not other, smaller molecules.

Movement of molecules or ions through a membrane against a diffusion gradient.

Evaporation of water from leaves and other parts of plants.

The idea that the force required to draw water from the soil and roots is generated by the evaporation of water from the leaves of plants.

The opening in a leaf surface through which gas exchange with the atmosphere takes place.

The depth of water or level of light at which respiration and photosynthesis balance each other; the lower limit of the euphotic zone.

Photosynthetic pathway in which carbon dioxide is initially assimilated into a three-carbon compound, phosphoglyceraldehyde (PGA), in the Calvin cycle.

Photosynthetic pathway in which carbon dioxide is initially assimilated into a four-carbon compound, such as oxaloacetic acid (OAA) or malate.

Photosynthetic pathway in which the initial assimilation of carbon dioxide into a four-carbon compound occurs at night; found in some succulent plants in arid habitats.

Having an osmotic potential (generally, salt concentration) greater than that of the surrounding medium.

Having an osmotic potential (generally, salt concentration) less than that of the surrounding medium.

The maintenance of constant internal conditions in the face of a varying external environment.

The tendency of a system to counteract externally imposed change and return to a stable state.

The ability to maintain a constant body temperature in the face of a fluctuating environmental temperature; warm-bloodedness.

Inability to regulate body temperature: cold-bloodedness (opp of homeothermy).

The capacity to maintain body temperature by gaining heat from the environment, either by conduction or by absorbing radiation.

The capacity to maintain body temperature by the metabolic generation of heat.

Loss of the power of motion and feeling, usually accompanied by a greatly reduced rate of respiration.

Movement of fluids in opposite directions on either side of a separating barrier through which heat or dissolved substances can pass.

The narrow range of environmental conditions to which an organism is best suited.

The parallel of latitude that lies directly under the sun at any given season.

Vertical and latitudinal circulation of air within the atmosphere driven by the warming effect of the sun.

The region within which surface currents of air meet near the equator and begin to rise under the warming influence of the sun.

Regions of high atmospheric pressure and dry air centered approximately 30 degrees north and south of the equator.

A dry area on the leeward side of a mountain range.

Vertical movement of water, usually near coasts and driven by offshore winds, that brings nutrients from the depths of the ocean to surface layers.

A pattern of climate found in middle latitudes, characterized by cool, wet winters and warm, dry summers.

The relationship of temperature to depth below the surface of the water or soil, or height above the ground.

The vertical mixing of water layers in temperate lakes in spring as surface ice disappears.

The zone of water depth within which temperature changes rapidly between the upper warm water layer (epilimnion) and lower cold water layer (hypolimnion).

The establishment of distinct layers of temperature or salinity in bodies of water based on the different densities of warm and cold water or saline and fresh water.

The warm, oxygen-rich surface layers of a lake or other body of water. (comp. with hypolimnion)

The cold, oxygen depleted part of a lake or other body of water that lies below the zone of rapid change in water temperature (thermocline). (comp with epilimnion).

The vertical mixing of water layers in temperate lakes in autumn following breakdown of thermal stratification.

The rapid growth of algae in temperate lakes following the autumnal breakdown of thermal stratification.

Along the bank of a river or lake.

Referring to habitats in which plant production is limited by the availability of water.

Referring to habitats with plentiful rainfall and well-drained soils.

The decrease in temperature with increasing elevation caused by the expansion of air the the lower atmospheric pressure.

A more or less distinct belt of vegetation occurring within and characteristic of a particular latitude or range of elevation.

The solid substrate of terrestrial communities, resulting from the interaction of weather and biological activities with the underlying geologic formation.

A layer of soil distinguished by its physical and chemical properties.

Physical and chemical breakdown of rock and its component of minerals at the base of the soil.

Breakdown and removal of clay particles from the acidic soils of cold, moist regions.

Leaching of silica from soil, usually in warm, moist regions with an alkaline soil reaction.

A major type of ecological community (e.g., the grassland biome).

One of several categories of the physical structure of plants, such as tree, herbaceous perennial, or liana.

Herbaceous, broad-leaved begetation (e.e., other than grasses) consumed by grazers.

The range of conditions within which a species can survive.

Pertaining to or influenced by the soil.

An adaptation of form or function that suits an individual particularly well to a restricted range of habitats, resources, or environmental conditions; the evolutionary process of such restriction.

A species that uses a restricted range of habitats or resources.

A species with broad food or habitat preferences.

A region in Heinrich Walter's classification of the climates of the earth defined by temperature and precipitation.

The period of the year during which conditions are suitable for plant growth; in temperate regions, generally between the first and last frosts.

An extensive area of level or rolling, almost treeless grass-land in central North America.

Usually treeless plains, especially in southeastern Europe and Asia in regions of extreme temperature range and sandy soil.

An underground, usually horizontal stem of a plant that produces both roots and aboveground shoots and that may be modified to store carbohydrate nutrient reserves.

Referring to the tough, hard, often small leaves of drought-adapted vegetation.

A moist coniferous forest bordering the arctic zone, dominated by spruce and fir trees.

A layer of permanently frozen ground in very cold regions, especially the Arctic and Antarctic.

The uppermost layer of vegetation in a forest.

Trees that rise above the canopy to heights of 55 m.

A layer of vegetation under the canopy of a forest.

A climbing plant of tropical rain forests, usually woody, that roots in the ground.

A plant that grows on another plant and derives its moisture and nutrients from the air and rain.

Water running over the surface of the land.

A shallow stretch of fast-moving, often rough water between quieter pools in a stream.

A stretch of slow-flowing, often deep water in a stream between riffles.

Referring to materials transported into a system, particularly minerals and organic matter transported into streams and lakes. (comp with autochthonous).

Along the bank of a river or lake.

Referring to materials produced within a system, particularly organic matter produced and minerals cycled within streams and lakes. (comp with allochthonous).

The idea that a river system encompasses a continuum of conditions from the headwaters to the mouth, characterized by increasing streambed size and water flow and interconnected by the movement of nutrients and organisms with downstream currents.

A body of fresh water in any kind of depression.

Pertaining to the shore of the sea, especially the intertidal zone, and often including waters to the depth limit of emergent vegetation.

Of or inhabiting the open water of a lake.

On or within the bottom of a river, lake, or ocean.

A semi-enclosed coastal water body, often at the mouth of a river, having a high input of fresh water and great fluctuation in salinity.

The distribution of organisms in bands or regions corresponding to changes in ecological conditions along a continuum, for example, intertidal zonation and elevational zonation.

The region of shallow water adjoining a seacoast.

Region of the ocean beyond the continental shelves.

On or within the bottom of a river, lake, or ocean.

Pertaining to surface waters to the depth of light penetration.

In lakes and oceans, the water layer below the depth to which light penetrates.

In tropical oceans, a structure built of living corals in the shallow water, often surrounding an island or ringing a submerged island, in which case the reef is an atoll.

A representation of the various paths of energy flow through populations in the community, taking into account the fact that each population shares resources and consumers with other populations.

All the interacting parts of the physical and biological worlds.

Relating to heat and motion.

A representation of the passage of energy from a primary producer through a series of consumers at progressively higher tropic (feeding) levels.

Pertaining to food or nutrition.

The concept that the energy flux through any given link in the food chain decreases with progressively higher trophic levels.

Assimilation (gross primary production) or accumulation (net primary production) of energy and nutrients by green plants and other autotrophs.

The rate at which primary production occurs within an ecosystem.

A green plant or other autotroph that assimilates the energy of light to synthesize organic compounds.

The total energy assimilated by plants through photosynthesis.

Energy accumulated in the tissues of plants.

Percentage of light energy assimilated by plants, based either on net production (net photosynthetic efficiency) or on gross production (gross photosynthetic efficiency).

The ratio of net primary production to transpiration of water by a plant, usually expressed as grams per kilogram of water; water use efficiency.

same as transpiration efficiency: The ratio of net primary production to transpiration of water by a plant, usually expressed as grams per kilogram of water.

A percentage expressing the proportion of ingested energy that is absorbed into the bloodstream.

The percentage of assimilated food used for growth and reproduction by an organism.

Freshly dead or partially decomposed organic matter.

The proportion of production on one trophic level that is consumed by organisms on the next higher level.

The ratio of the size of a compartment to the flux through it, expressed in units of time; thus, the average time spent by energy or a substance in the compartment.

The ratio of weight to annual production.

Referring to a biochemical transformation that results in the reduction of an element to an organic form and hence its gain by the biological compartment of the ecosystem.

Referring to a biochemical transformation that results in the oxidation of the organic form of an element and hence its loss from the biological compartment of the ecosystem.

A representation of a system in which the various parts are portrayed as units (compartments) that receive inputs from and provide outputs to other such units.

Biological assimilation of atmospheric nitrogen to form organic nitrogen-containing compounds.

Metabolic breakdown of proteins and amino acids with ammonia as an excreted by-product.

Breakdown of nitrogen-containing organic compounds by microoganisms, yielding nitrates and nitrites.

Biochemical reduction, primarily by microorganisms, of nitrogen from nitrate (NO3)- eventually to molecular nitrogen (N2).

An organism that uses sunlight as its primary energy source for the synthesis of organic compounds.

An organism that oxidizes inorganic compounds (often hydrogen sulfide) to obtain energy for synthesis of organic compounds (e.g., sulfur bacteria).

The drainage area of a stream or river.

Close associations of fungi and tree roots in the soil that facilitate the uptake of minerals by trees.

Mutualistic associations of fungi with the roots of plants in which part of the fungus resides within the root tissues.

Mutualistic associations of fungi with the roots of plants in which the fungus forms a sheath around the outside of the root.

A hard substance rich in oxides of iron and aluminum, frequently formed when tropical soils weather under alkaline conditions.

Rich in the mineral nutrients required by green plants; pertaining to an aquatic habitat or soil with high productivity.

Poor in the mineral nutrients required by green plants; pertaining to an aquatic habitat with low productivity.

Enrichment of water by nutrients required for plant growth; often refers to overenrichment caused by sewage and runoff from fertilized agricultural lands and resulting in excessive bacterial growth and oxygen depletion.

The amount of oxygen required to oxidize the organic material in a water sample; high values in aquatic habitats often indicate pollution by sewage and other sources of organic wastes, or the over-production of plant material resulting from overenrichment by mineral nutrients.

Water runoff from surface mining, usually coal strip mining, containing sulfuric acid, which forms when organic sulfur is oxidized on contact with the atmosphere.

Restoration of natural habitats or ecological conditions by use of biological agents (e.g., bacterial degradation of spilled oil or other pollutants).

A region of severe ozone depletion in the upper atmosphere, usually at high latitude.