Glossary of pelagic biogeography r. K. Johnson†, B. J. Zahuranec*, D. Boltovskoy and A. C. Pierrot-Bults
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dichotomous character caracter dicotómico A character that exists in only two states, a binary character, eg present vs absent. dichotomous key clave dicotómica An identification key constructed as a sequence of alternative choices; each pair forming a character couplet.
Twice daily movement of planktonic or micronektonic organisms in response to day:night shift in light intensity. Typically migrating organisms are found at shallower depths during nighttime, deeper depths during daytime. Sometimes (incorrectly) termed diurnal vertical migration. differentiation diferenciación (1) Biology: Changes in structure and function of a group of cells with increasing specialization during ontogeny. Loss of totipotency (qv). (2) Biogeography: The origin of difference(s) between different organisms or biotas as a result of evolution and/or other processes.
Applied to a body of water (typically a midlatitude lake) in which occur two seasonally driven turnover events.
(1). Evolution: Anagenetic speciational trend in which there is an apparently directed (orthogenetic)stepwise succession of species or forms, presumably reflecting longterm, monotonic selection (cf anagenesis, orthogenesis). (2). Genetics: Selection that changes the frequency of an allele in a constant direction, often used in agriculture/horticulture (cf disruptive selection, stabilizing selection).
Sampling protocol employing equipment that allows capture of organisms within a limited and defined depth stratum, with little or no contamination (unwanted captures) in depths shallower (or deeper) than the specified stratum. Essential to description of diel vertical migration (qv), seasonal and ontogenetic shifts in depth, etc. (cf open net haul). disharmony Ecology: In biodiversity, the overrepresentation of some groups of organisms and under- representation or absence of others due to accidents of dispersal. Encountered frequently in dealing with oceanic islands but may apply elsewhere. disjunct disyunto Distinctly separate; used of a discontinuous range in which one or more populations are separated from other potentially interbreeding populations by sufficient distance or other barriers to preclude effective gene flow between them.
Tendency of an organism to move away from its birth (natal) or breeding site (cf philopatry). dispersal biogeography biogeografía dispersiva Study of the geography of organisms through the center-of-origin/dispersal approach (qv). dispersion dispersión Statistics: The internal pattern of variation within a population, eg variation in the value of a character around a mean value. In spatial statistics the pattern relative to some specific location of individuals relative to one another (cf even, random, aggregated). disphotic (dysphotic) zone zona disfótica Middepths of the ocean (or in freshwater) where light intensity is sufficient during daylight hours to cue diel photic response or visual detection, but insufficient to support net positive photosynthesis (cf euphotic, aphotic). disruptive selection selección disruptiva Population biology: Selection that changes the frequency of alleles in a disjunctive or divergent manner, leading to bimodality (or multimodality), ie the fixation of alternative alleles in members of the population, which, after several generations, should result in two (or more) divergent phenotypic extremes in the population, with few or no intermediate phenotypes (cf directional selection, stabilizing selection).
Systematics: Any measure of dissimilarity between taxa. distribution distribución (1) Biogeography: The geographical range of a taxon or group. (2) Ecology: The spatial pattern or arrangement of the members of a population or group (cf dispersion).
Active during daylight hours (cf crepuscular, nocturnal). diurnal vertical migration migración vertical diurna See diel vertical migration. divergence divergencia (1) Evolution: Change in allele frequencies in a population. Also: genetic segregation and/or differentiation within a taxon to the extent that distinct derivative taxa result (cf anagenesis, cladogenesis). (2) Oceanography, meteorology: Net outward flow (loss) from a particular stratum, with deeper fluid upwelling to replace it, as at the surface along the equator in the Pacific. The opposite of convergence (qv).
Evolution: Increase in the diversity of distinct types in one monophyletic lineage. diversity diversidad Ecology: Measure of the taxonomic complexity of a community with the components of species richness (number of species) and dominance or equitability (the distribution of individuals among species). Often measured by indices that estimate the likelihood that two individuals of the same species will be selected on successive random samples from the community. diversity index índice de diversidad Mathematical expression of the species diversity of a given community or area, typically including components of both species richness (qv) and equitability (qv).
Dissolved organic carbon. That fraction of nonliving organically bound carbon in seawater that will pass through a filter of stipulated pore size (often 0.45 mm). By far the largest fraction of organically-bound carbon in sea water. doldrums zona de calmas ecuatoriales Meteorology: Oceanic equatorial zone with low pressure and light variable winds at the surface, reflecting the overhead ascending arm of the tropical Hadley Cell (qv). The zone moves seasonally north and south with respect to the equator (cf convection, trade winds). domain dominio Oceanography: Unique identifiable bodies of water with consistent properties, climatic locality and continuity. For example Transitional Domain (cf transition region). dome domo Oceanography: An area of recumbent (return) flow in an equatorial current system resulting in upwelling (qv) as indexed by marked shoaling of isotherms and other features, as in the Guinea Dome (eastern tropical Atlantic) or Costa Rica Dome (eastern tropical Pacific). dominance dominancia Ecology: Applied to species that are conspicuously successful in competition. The species having the most influence on community composition and form; also used to describe the most conspicuous, or largest and/or most abundant species in a community. dominance hierarchy jerarquía de dominancia (1) Behavior - Social order of dominance sustained by agonistic or other behavior, eg pecking order. (2) Ecology - listing in rank order by species of community components, the most abundant species is listed first, the next most abundant second, and so forth. dominant species especie dominante The species having the greatest influence on community composition and form. downwelling hundimiento (de masa de agua) Sinking of ocean surface waters, as in the central regions of an oceanic anticyclonic Gyre (cf upwelling).
(1) Oceanography: Movement of objects at the ocean surface associated with advection by currents or being blown by the wind. (2) Geology: Any sediment laid down through the activity of glacial ice. (3) Geophysics: Movement of crustal plates, including continents or portions thereof, relative to the mantle. DSL capa difusora profunda (CDP) Deep scattering layer. A sonically interfering stratum of organisms causing sensible acoustic return on sonar equipment, often yielding an acoustic signature as a false bottom.
The condition of being stunted, much smaller than normal, having restricted growth. dynamics dinámica Movement of objects and the forces thereunto related, in a Newtonian Laws of Motion sense. In modern ocean science jargon has come to mean studies directed toward elucidation of function and prediction as opposed to static description. dysphotic disfótico See disphotic. dystrophic distrófico Pertaining to overproductivity in aquatic environments, usually related to abnormally high nutrient load, resulting in choking overgrowth of aquatic vegetation (cf eutrophic, oligotrophic). In a lake typically associated with bog and peat production and anoxia in bottom waters and/or sediments.
An ooze-inhabiting community. E East Pacific Barrier barrera del Pacífico este The barrier to dispersal of shallow-water marine organisms (as well as terrestrial organisms) imposed by the vast islandless expanse of the eastern Pacific Ocean.
The relatively shallow, slow, high productivity near-coastal limb of the great subtropical anticyclonic gyres found on the eastern margin of oceans (especially the Atlantic and Pacific); eg the California, Peru, Canary and Benguela Currents. ebb tide marea bajante The receding or outward flowing portion of the tidal cycle (cf flood tide). ecdemic alóctono Foreign, non-native, introduced (cf endemism). ecesis (œcesis) The pioneer stage of dispersal to a new habitat; successful invasion and establishment. eclectic ecléctico Composed of theories, doctrines, protocols or paradigms drawn from a number of different sources; willingness to use that which works in place of that which is desired. Pragmatic. ecogeographical rule regla ecogeográfica Any generalization describing a trend of geographic variation correlated with environmental conditions (cf Bergmann's rule, Jordan's laws).
Graphical representation of trophic structure and function of a community or ecosystem; may consist of plots of numbers (abundance) or biomass or energy. Illustrates that energetically the autotrophs are always dominant but in standing stock terms grazing pressure may result in so-called inverted pyramids (biomass only) for short periods of time. ecological amplitude amplitud ecológica A component of "potential niche" (cf fundamental niche) - range of tolerance of a given organism to any one environmental parameter (temperature, salinity, etc), often exhibiting a bell-shaped response curve or nearly so.
The study of animal distribution with emphasis on environmental association, usually emphasizing present not longterm interactions, seeking to utilize pattern in environmental parameters (physical, chemical, biological) to elucidate understanding of pattern in the distribution of single species and assemblages of species. ecological efficiency eficiencia ecológica Ratio of output to input of mass and/or energy at any given trophic level (qv) (also applied to single species or populations or parts or assemblages thereof).
See niche. ecological race raza ecológica A race (qv) that owes its most conspicuous attributes to the selective effect of a specific environment, usually localized or of limited distribution. ecologically equivalent species especie ecológicamente equivalente Pairs of independently evolved but ecologically similar species occupying similar niches in different communities; also termed complementary species.
Study of the interrelationships among organisms and between organisms and all aspects of their environment, both living and nonliving.
All naturally occurring phenotypes produced within a given habitat by a single genotype. ecophenotypic ecofenotípico (1) Denoting nongenetic modification of the phenotype by specific ecological conditions, particularly those associated with a particular habitat. (2) Variation caused by nongenetic responses of the phenotype to local conditions of habitat, climate, etc. ecosystem ecosistema Used to describe the interdependence of species in the living world (biome (qv) or community (qv)) upon one another and with their nonliving (abiotic) environment. Energy flow, material flow and biogeochemical interactions are among the fundamental components of ecosystem-level studies. ecotone ecotono Relatively narrow and sharply defined transition zone between two or more communities. Edge communities or assemblages (those associated with ecotones) are commonly species rich with elements of both communities present (although in extreme ecotones (land to sea, freshwater to salt water) the reverse may be true). ecotype ecotipo A descriptive term applied to local races (especially plants but also zooplankton) of varying degrees of distinctiveness which owe their most conspicuous characters to the selective effects of local environments. ecronic estuarial Estuarine. ectotherm ectotérmico See poikilotherm. eddy torbellino, rulo, giro, vórtice Oceanography, meteorology: Small or mesoscale (cf mesoscale feature) motion of fluid (air or water) in different directions (including at some points contrary to the direction of the large-scale current with which they are associated) usually in circular form. Eddies vary in size from small-scale turbulence to such mesoscale features as cold core (qv) and warm core rings (qv). edge effect efecto de borde Ecology: (1) The effect exerted by adjoining communities on the population structure within the marginal zone (ecotone), which often contains a greater number of species and higher population densities of some species than either adjoining community. (2) In biofouling studies pertains to differences in the composition and abundance of organisms occurring at the edge of a structure compared to the center of the structure (eg fouling panel). edge species especie de borde A species found predominantly or commonly in the marginal zone (ecotone) of a community. Ekman divergence divergencia de Ekman As a consequence of the Coriolis effect and friction, surface drift in response to the wind is 90° to the right of the wind over the depth of the Ekman layer (qv) in the northern hemisphere. Thus sustained longshore winds cause offshore divergence of surface waters with the consequence of coastal upwelling, a most important feature of eastern boundary current ecosystems, at least seasonally.
The thickness of the layer of water affected by the Ekman spiral, Ekman surface drift, and hence Ekman divergence; a function of wind speed and latitude: DE ~= 4.3 W /(sin f)1/2 (where DE = Ekman Layer depth, W is wind velocity, and f is the latitude, in appropriate units), approximately 50 m for a wind of 10 m sec-1 at 45° N. El Niño Oceanography: Collapse of the normal upwelling regime in the eastern Pacific, particularly in the Peru Current, associated with trans-Pacific flushing of warm wind-mixed layer water during an ENSO (qv) event . electivity selectividad Ecology: Measure of the degree of prey selection by a predator in relationship to the prey available (cf coarse-grain exploitation, fine-grain exploitation).
Term designating a population (s) differing from another such population (s) in the electrophoretic mobility of one or more enzymes (cf allozymes).
See ecological pyramid. eluvium A sand dune community (synonym: enaulium). emersal Applied to eggs and/or larvae, typically of fishes, where the parents may spawn on or near the bottom or in the water column but the eggs and smallest larvae and juveniles are typically near the surface, at the shallowest depth for the species (cf demersal). emersed aquatic plants plantas emergentes Plants that are partially emergent, typically referring to freshwater aquatic plants. emigration emigración Biogeography: Movement of an individual or group out of a geographical region (cf immigration). enaulium See eluvium. endemism endemismo Confined to; occurring nowhere except in the place of reference. Situation in which a species or higher taxonomic group is restricted to a particular geographic region, reflecting history, ecology and opportunity (synonyms: exclusive, peculiar, precinctive, provincial). endobenthic endobéntico, infaunal Organisms that live in the surface sediments on the sea floor (cf epibenthic, hyperbenthic, infauna). endogenous rythm (rhythm) ritmo endógeno A recurring behavior pattern, the cues for which arise or originate internally within the organism or system, eg the observation of daily activity patterns even when light is held constant; biological clock. (cf zeitgeber). endolithic endolítico Of or pertaining to organisms that live in rocks (or hard substrata such as dead coral) (cf lithophagic). endotherm endotérmico See homoiotherm. engibenthic (engybenthic) Of or pertaining to close association with the sea floor. enrichment enriquecimiento Ecology: Addition of nutrient(s) to an ecological system. ENSO event fenómeno de El Niño Oceanography: Acronym from El Niño - Southern Oscillation. A global coupled atmosphere-ocean event with El Niño (qv) as one effect. Caused by a weakening of the trade winds, especially the SE trades, in the Pacific, associated with anomalously high pressure over Indonesia, resulting in a considerable volume of warm mixed-layer water moving eastward along the equator in the Pacific in the form of a series of Kelvin waves. entrainment Oceanography: Energy driven incorporation of one parcel of water into the flow of another, as in the entrainment of deeper, more saline, denser water upward into outflowing fresher water (typically river discharge) at the mouth of a river, distributary or estuary.
Ecology: The complete range of external conditions, physical, chemical and biological, in which an organism lives.
The sum total of environmental limiting factors, both biotic and abiotic, which constrain the potential niche of an organism to its realized niche (qv).
Epicontinental sea (qv). epibenthic epibéntico Of or pertaining to organisms that live on the surface of the sea floor (cf endobenthic, hyperbenthic, infauna). epibiota An organism or group of organisms occurring commensally on the surface of another organism.
A shallow sea extending far into the interior of a continent, eg Hudson's Bay, Baltic Sea.
Pertaining to the tide pools of the upper shore. epideictic A specially timed communal aggregation within a population, possibly for interbreeding. For example one proposed function for diel vertical migration (qv) is social facilitation (qv) of interbreeding. epifauna Of or pertaining to animals that live on as contrasted to living within a substratum (living or nonliving) (cf benthos, infauna, phoresy). epilimnion epilimnio Upper warm relatively thin (usually) mixed layer in a thermally stratified lake in summer - lying over the deeper usually considerably thicker cold hypoliminion (qv).
Organisms living on the surface film of a body of water (cf hyponeuston). epipelagic epipelágico (1) Stratum between 0 - 200 m in the offshore ocean. (2) In the oceanic realm, the euphotic (qv) zone, where light levels permit positive net rates of photosynthesis. (3) Pelagic organisms found during daylight within these depth limits.
Growing on mud. epiphyte epifítico Plant that uses another plant, such as a tree or giant kelp, for physical support, but does not draw nourishment from it. epipleuston Organisms which move over the surface film of water with most or all of their bodies above the water.
Microscopic flora and fauna found on the surface of and/or attached to sand grains. epitokous epitóquico Reproductive; having or producing offspring. epizoic epizoico An organism or group of organisms living commensally on the surface of an animal. Yüklə 0,85 Mb. Dostları ilə paylaş:
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