Ecology Glossary

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Select words and phrases from the field of geography and conservation biology.


Achenes  Single-seed fruit.

Ambits  Areas that are scaled to a particular ecological process, a time period, and an organisms mobility or activity.

Stage or period at which flower- bud opens; flowering; period of flowering.


Birth-flow population
Reproduction occurs continuously over time interval.

Birth-pulse population
Reproduction is concentrated in a short breeding season.

Soaring habit and long, borad wings.  The name of a large genus of buteoine hawks.

A subfamily of Accipitridae containing the so-called buzzard-hawks distinguished from the Accipitrinae by their soaring habit and long, broad wings.



Community interaction webs
Includes both links between consumers and their prey, as in traditional food webs, and also links representing other potential direct interactions, notably interference competition.

Any crustacean of the subclass Copepoda, compromising mostly  microscopic free-living forms, as Cyclops, Calanus; important as fish food.  Some are parasitic.

Narrow strips of land which differ from the matrix on either side.

1. A swollen underground stem designed for food storage and which serves as a resting phase of the plants involved.  Corms, such as those of the crocus and gladiolus, are often erroneously called bulbs.

2. In the sense of an entire plant, or plant organ system.

3. A group of individuals, such as a colony of hydrozoan colenterates, all members of which are both morphologically and physiologically united.

A new corm produced from the base of a “mother” corm.

Cryptic germination
Seed may produce only a root at first and delay sending up a shoot until the following growing season.


Demographic stochasticity
Inherent variation in individual reproduction rates and times of death that are not due to differences in ecological conditions

Day and night.

A developmental process by which a relatively unspecialized cell undergoes a progressive change to a more specialized function; differentiation in plants may be reversed under suitable conditions, but it is rarely reversible in animals.

Direct interactions
Species physically interact (consumption, territoriality, interference competition, pollination).

An event that causes a significant change from the normal pattern in an ecological system.

Disturbance patch
Small area in a matrix that is disturbed.


An outgrowth from the surface of a seed, containing fats or oils.  They are sometimes attractive to ants, hence aiding in seed-dispersal.

Emergent substrata
Rock exposed to air at low tide.

Benthic organisms that life on the surface of the seabed, either attached to objects on the bottom or free-moving.  They are characteristic of the intertidal zone.

Diapausing eggs.


Acronym for evolutionary stable strategies.




A family of gammaridean amphipod Crustacea common in marine habitats and in all the freshwaters of the world where they form a major item in the diet of fish.  It is a very large a varied family and more than half of the species are confined to Lake Baikal.  The larger forms are popularly called scud.

A suborder of amphipod crustacea distringuised from the Caprellidea by the presence of a fully developed abdomen and usually the presence of seven free thoracic segments and from the Hyperiidea by the usual presence of coxal plates and the legs, by the small head and eyes and the absence of palps on the maxillipedes. The beach hoppers and the fresh water gammarids are the best known.

G by E 

Generation by environment.


Age of maturity plus the time to produce the first clutch of offspring.


Hard-wired behaviour
Relatively fixed behavior which doesn’t track environmental cues.



The alternation of reproduction by parthenogenesis and bisexual reproduction.

Leafhoppers, aphids


Indirect interaction 

Those effects of one species on another don’t involved physical interaction.

Indirect mutualism
One species may indirectly enhance a second species on the same trophic level if it primarily consumes species that compete with the preferred prey of the second species.

Benthic organisms that dig into the sea bed or construct tubes or burrows. They are most common in the subtidal and deeper zones (i.e. the area seaward of the low-water mark).

The grouping of flowers set apart from the foliage into racemes and like.

Intertidal zone
An area between the highest and lowest tidal levels in a coastal region.

Multiple reproduction in life span.


Keystone species
A species that has an affect on its community disproportionate to its abundance.


Pertaining to lakes.

Lawnmower theory
Predators, by keeping the abundance of their prey in check, prevent competitive exclusion and thus permit or maintain a higher species richness than would occur in their absence. Also know as the “predation theory”. (From Paine 1966).

Lactate Dehydrogerase.  The enzyme which produces pyruvic acid.

Larvae develop from yolk supplies in ovum and do not feed.  Some lec. May be capable of facultative planktotrophy.

Leslie Matrix
Age-classified matrix. Population projection matrix.

Line corridor
Narrow bands essentially dominated throughout by edge species.

Littoral zone
1. The area in shallow, fresh water and around lake shores, where light penetration extends to the bottom sediments, giving a zone colonized by rooted plants.

2. In marine ecosystems the shore area or intertidal zone, where periodic exposure and submersion by tides is normal.


Markovian process
Present state under dependent upon previous time state.  First order Markov.

A surrounding area that has a different species structure or composition.

Considers a population in a region as being made up of local populations.  These populations are linked by dispersal.


Areas where the corridors take on the form of an isthmus.

The range of conditions, resources, etc. Permitting populations of a species to persist (deterministically) without immigration.

Niche conservatism
Observation that phylogenic lineahes often retain much the same niche over substantial spans of evolutionary history.

Patches of similar vegetation attached to the corridor.

An immature stage (following hatching) of a hemimetabolous insect that lacks a pupal stage.


The course of development of an individual from egg to senescence.

A cell with a diploid nucleus, which, by meiosis, gives four haploid nuclei, which ultimately form female gametes, usually by further division.

The development of an egg from an oocyte.


The development of an individual from an egg without that egg undergoing fertilization.  The eggs (ova) that develop are usually diploid, so all offspring are genetically identical to the parent. Commonly, parthenogenesis with only females in the population alternates with ordinary sexual reproduction, which allows the recombination of genetic material presents a need for males. This alternation is called heterogamy.

Non-linear surface area differing in appearance from its surroundings.

Patch turnover
The rate at which patches appear and disappear.

Usually in the sense of a stalk bearing one part rather than a connection between two parts and thus applied to the stalk of a barnacle, or the main stem of an inflorescence.

See peninsuloid.


A narrow extension or lobe of a patch.

Peninsular interdigitation
Peninsuloids of one landscape element interfinger with those of a second type.

The probability that an individual in age class i will survive from t to t+1.

Stream area just below foothills. Area before one reaches delta region.

Phosphoglucose Isomerase. 


Larvae derive nutrition through feeding.

A family of pulmonate gastropods usually having flattened, or very low spiralled, shells.  Commonly called orb snails.

Trait or behaviour al changes in response to environmental cues.

Predation hypothesis
Predators, by keeping the abundance of their prey in check, prevent competitive exclusion and thus permit or maintain a higher species richness than would occur in their absence. (From Paine 1966). Also know as the “lawnmover theory”.

Primordium pl. Primordia
A cell or organ in its earliest stage of differentiation.


Relaxation period
Time following a disturbance during which the extinction rate is elevated.

Any structure the parts of which are arranged radially.  Specifically applied to a central disk of fused plates in the vault of a crinoid calyx.


1. A stem arising from the ground which bears a flower at its tip, and which is devoid of leaaves. The term is also used as synonymous with stipe.

2. In insects, the long basal joint of a geniculaate antenna.

Sequential hermaphroditism
Change in sex over time. Sex is determined by some unknown aspect of the external environment as reflected in an individual’s internal physiology, and its sex can change when it’s physiological state changes. (Ex. – Jack-in-the-pulpit Arisaema triphyllum).

1.  A spike with an usually fleshy axis in the Araceae.

2.  That portion of a blastostyle on which sporosacs develop.

3.  The copulatory organ of the cephalopod mollusc Natilus

A large bract enclosing a spadix.

Species-area curve
The plotted relationship between increasing area of habitat and the number of species.

Storage effect
Although an organism or a population may experience considerably reduced or even complete loss of recruitment in years favourable to its competitor, it can persist so long as there are life-history stages that are viable for periods long enough to experience the next favourable year.

Stream corridors
Border water courses and vary in width according to the size of the stream.

Strip corridor
Wider bands with a central interior enviornment that contains an abundance of interior organisms.

Immediately hatching eggs.


Theory of island biogeography
The number of species on a given island is correlated with three factors: island’s area, its isolation, and its age.



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