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This glossary contains words or phrases used throughout one or both volumes of the Natural History of Nova Scotia. Words or phrases that appear only within a specific context in the document are generally not included in this glossary, because their definitions can usually be found under the relevant topics or habitats. A through M

A

ablation till
A surface deposit of loose, permeable, somewhat stratified sandy and stony till overlying denser till.

Acadian Forest
A transitional zone within the Southeastern Mixed Forest defined by Rowe in 1972 as the area between the coniferous Boreal Region to the north and the Deciduous Region to the south. This forest is characteristic of the Maritime Provinces and, being transitional in nature, includes a variety of forest associations.

Acadian Orogeny
A time of mountain building during the Devonian period.

accretion or aggradation
Natural accretion is the buildup of land on a beach by natural deposition of waterborne or airborne material. The process may be managed or accelerated by human action.

acidification
The lowering of pH in soils or water. Commonly associated with changes caused by external processes such as acid precipitation and acidic runoff.

acid precipitation
Rain water or snow containing sulphur and nitrogen compounds and other pollutants associated with industrialization.

acritarchs
An apparently unicellular microfossil of unknown biological affinity ranging in age from Precambrian to Holocene.

aeolian
See eolian.

aerobic
Environmental condition where oxygen is present; usually applied to the condition of water or soil.

Alleghanian
Referring to species associated with deciduous forests to the south.

allies
A non-specific term indicating groups of organisms closely related by likeness, etc.

alluvial deposits (alluvium)
Material such as clay, silt, sand, and gravel deposited by modern rivers and streams.

altered rock
A rock whose nature has been changed by geological processes.

amphibolite
A metamorphic rock composed mainly of silica-based rock-forming minerals.

amphipods
A group of crustaceans that includes freshwater shrimps.

amygdaloidal
Containing gas bubbles trapped in lava that were subsequently filled with (often semiprecious) minerals, for example, in basalt.

anadromous
Used to describe fish that spawn in fresh water after spending most of their lives in the sea.

anaerobic
Environmental condition where oxygen is absent or in limited supply; usually applied to the condition of water or soil.

andalusite
A brown, yellow, green, red, or grey mineral (an aluminum silicate) associated with regionally metamorphosed shales.

angular discordance
See angular unconformity.

angular unconformity
An unconformity in which younger sediments rest upon the eroded surface of tilted or folded older rocks.

anhydrite
Anhydrous calcium sulphate; a common mineral in evaporite deposits, usually occurring in massive beds.

anorthosite
A coarse-grained igneous rock composed almost entirely of soda lime­based feldspar, distinctive in its lack of quartz.

anticline
A fold in the layers of rock caused by deformation of the earth's crust. The older strata are found towards the centre of the fold.

antimony
A native metallic element, and mineral, that occurs in silvery or tin-white granular, platy, or shapeless masses.

aplite
Generally refers to a dyke rock made almost entirely of light-coloured minerals and with a characteristic fine-grained granitic texture.

Appalachian
A name derived from the Appalachian mountain system of northeastern North America and applied to the Appalachian geological region of North America, of which Nova Scotia is a part.

aquifer
A layer of wet sand or porous rock below the earth's surface capable of producing water, as for a well.

arable soil
Soil suitable for ploughing and cultivation.

arctic-alpine
Referring to a geographic range for plants and animals. Includes those typically found north of the tree-line and at high elevations; found in habitats with climatic conditions resembling those of the arctic or high elevations.

arctic-boreal
Referring to a range of plants and animals. Includes those found in climatic conditions resembling that above the tree-line (tundra) or within the northern coniferous forest just south of the tundra.

arsenopyrite
A mineral of iron, sulphur, and arsenic commonly associated with metamorphism around igneous intrusions as in the quartz veins of the Meguma Zone of Nova Scotia.

arthropods
Members of a major group or phylum of invertebrate animals with hard exoskeletons, segmented bodies, and jointed appendages; includes crustaceans, insects, spiders, etc.

association
A group of species living in the same place.

Aufwuchs
A German word applied by ecologists to small organisms found on the surfaces of aquatic vegetation, etc., in freshwater habitats.

aureole
An area surrounding an igneous intrusion where changes to the original rock have been caused by heat from intruding magma; synonymous with contact zone.

autotrophic
Said of organisms that use sunlight to create food.

avifauna
All bird species.

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B

baleen whales
Whale species that use a hairy plate to sieve small fish and invertebrates from water.

banks, offshore
Generally a large elevated area on the sea floor surrounded by deeper water; a submerged plateau or shelf.

bar
Submerged or emerged embankment of sand, gravel, or other unconsolidated material built in shallow water by waves and currents.

barachois pond
A small lagoon formed when spits created by currents that meet on a straight shoreline coalesce into an enclosing triangular beach.

barite
An industrial mineral, the principle ore of barium, used in textiles, paints, drilling muds, and pharmaceutical products.

barrier beach
A stretch of sand dune or cobble bar that separates a coastal body of water from ocean waters in all but exceptionally high tides, or during storms.

basal till
The bottom layer of glacial till deposited on an eroded bedrock surface.

basalt
A fine-grained, sometimes glassy, basic (i.e., low in silica content) igneous rock.

basement rocks
Older igneous and metamorphic rocks (mainly Precambrian) that are generally covered unconformably by younger sedimentary rocks.

batholith
A large intrusion of igneous rock, usually granite, with 100 km 2 or more of surface exposure.

bathymetric
Data on the depth of a body of water obtained through the measurement and charting of the topography of the bottom.

baymouth bar
A bar extending partially or fully across the mouth of a bay.

beach
A gently sloping area of unconsolidated material, typically sand, but also cobble or shingles, that extends landward from the water to where a marked change in material or form occurs, or to the line of permanent terrestrial vegetation.

beach terrace
A terrace or flat, horizontal surface formed when an old shoreline has been isolated by lowering sea levels.

bedforms
Any deviation from a flat bed, generated by the flow of an alluvial channel.

bedrock
Any solid rock exposed at the surface of the earth or overlain by unconsolidated material.

bench
See terrace.

benthic
Living at the bottom of a fresh or salty body of water.

benthos
Plants and animals that live on, in, or attached to the sea bottom.

berm
A low, incipient, nearly horizontal or landward-sloping area, or the landward side of a beach, usually composed of sand deposited by wave action.

bioclimate
A small-scale climatic condition generated by living organisms.

biodiversity
The variety of life in all its forms contained within a given space at a particular time.

biomass
1. The quantity of living and/or dead organic matter in an ecosystem. 2. A measure of the dried weight of all organic matter in an ecosystem.

biophysical
Refers to a hierarchial land classification system with units characterized by distinct biotic and abiotic elements.

biotite
A widely distributed rock-forming mineral of the mica group. It is generally black, dark brown, or dark green and forms a component of crystalline rocks (either as an original crystal in igneous rocks, or as a product of metamorphic origin in gneisses and schists) or a detrital component of sedimentary rocks.

bivalve
A mollusc with two shells, for example, a clam or mussel.

bloom
Rapid growth of a population of planktonic organisms, usually, but not limited to, phytoplankton.

bluff
A cliff with a broad face, or a relatively long strip of land rising abruptly above surrounding land or water.

boreal
Refers to species characteristic of the biogeographical area that extends across northern Canada south of the tundra.

boulders
Rock fragments larger than 60 cm in diameter.

brachiopods
Marine animals with two unequal shells or valves that are normally bilaterally symmetrical. They range in age from lower Cambrian to Present.

brackish water
Salty water with less salt than seawater.

brownwater lake
See dystrophic.

bryophytes
A division of the plant kingdom that includes mosses and liverworts. Plants with rhizoids rather than roots, and little or no vascular tissue.

Bryozoa
A phylum of tiny colonial animals that build calcareous structures of many kinds, mostly marine, ranging in age from Ordovician to Present.

buffering capacity
Ability to neutralize acidic input.

buoyancy
Ability of things to float in a liquid; applied to the tendency of less-dense water to remain above denser water in the ocean.

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C

calcareous
Containing salts of calcium, for example, calcium carbonate as limestone rock or derived soil.

Cambrian
The period that extended from at least 580 million years ago to 500 million years ago.

canopy
The top layer formed by the tallest trees in a forest.

capability class
A rating that indicates the capability of land for some use such as agriculture, forestry, recreation, or wildlife. In the Canadian system, it is a grouping of lands with the same relative degree of limitation or hazard. The degree of limitation or hazard is nil in Class 1 and becomes progressively greater to Class 7.

carbonate
A rock (e.g., limestone, dolostone) consisting of carbonate minerals, e.g., calcite, dolomite.

carbon cycle
The cycle whereby carbon dioxide is fixed in living organisms by photosynthesis or chemosynthesis; is consumed in carbohydrate, protein, and fat by most animals and plants that do not carry out photosynthesis; and ultimately is returned to its original state when freed by respiration and by the death and decay of plant and animal bodies.

Carboniferous
A geological period extending from 370 to 270 million years ago.

Carboniferous sea
A marine incursion during the early Carboniferous Period that formed an inland sea where deposition of limestone, salt, gypsum, and anhydrite occurred.

carnivores
Animals and a few plants that consume dead or living animal food.

catchment basin
See drainage basin.

catena
A non-taxonomic group of soils about the same age, derived from similar parent materials and occurring under similar climatic conditions but having unlike characteristics because of variations in relief and drainage.

centripetal
A force that makes a moving body move in a circular manner towards the centre.

cephalopod
One of the Cephalopoda. A marine invertebrate characterized by a head surrounded by tentacles and, in most fossil forms, by the presence of a straight or spirally coiled, calcareous shell divided into numerous interior chambers; ranges in age from Cambrian to present.

chain lakes
A series of connected lakes.

chlorite
A group of platy, usually greenish minerals associated with and resembling micas. Chlorites are widely distributed and are often found in low-grade metamorphic rocks.

Cladocera
Order within the class Crustacea that includes the water flea.

clastic
Usually refers to rocks composed of pre-existing rock fragments produced from weathering and erosion.

clay
1. A mineral soil particle less than 0.002 mm in diameter. 2. A soil textural class containing 40 per cent or more clay, less than 45 per cent sand, and less than 40 per cent silt.

cleavage
The tendency of a mineral to break along planes of weak bonding.

climax forest
A forest whose composition is more or less stable and is in equilibrium with existing environmental conditions.

coal seam
A stratum or bed of coal.

coastal fresh marsh
A tidal marsh moderated by the effects of freshwater runoff.

coastal plain
An area of relatively low land of variable width lying between uplands and the sea. In northeastern North America much of the coastal plain has been submerged as a result of post-glacial sea-level change. The term is often used in connection with distinct associations of plant speciescoastal-plain florawhose range extends from Nova Scotia to Florida at sea level. In Canada, their range is limited to the Great Lakes Basin and southwestern Nova Scotia.

coastline
The boundary between the coast and shore, or land and water.

cobbles
Water-worn rock fragments 7.5­25 cm in diameter.

co-dominant
Forming part of the main structure of a plant community, e.g., the canopy of a forest; sharing in the controlling influence of a biotic community.

colluvial deposit
Weathered material deposited by gravity; e.g., a talus slope.

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

conductivity
A measure of the ability of waters to conduct electricity. It increases as the amount of dissolved minerals (ions) increases. The micromho is the inverse of the measure of resistance, the ohm.

conglomerate
A coarse-grained (greater than 2 mm), clastic sedimentary rock containing rounded fragments set in a fine-grained matrix that is often cemented with calcium carbonate.

contact
The place or surface where two types of rock come together.

contact zone
See aureole.

contour
A line drawn on maps that joins points of equal elevation.

convection
Movement of portions of a fluid as a result of density differences produced by heating. Applied to circulation in the atmosphere, lakes, and oceans.

copepods
A group of mostly free-living planktonic crustaceans that forms an essential link in the food chains of lakes and ocean.

Cordilleran flora
Plants characteristic of boreal deciduous woods, which are common on the Pacific coast and in the Rocky Mountains.

cordierite
A common mineral in metamorphic rocks, considered an indication of intensive heat and pressure. A magnesium-iron-aluminum silicate.

Coriolis effect
The tendency of all particles in motion on the surface of the earth to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

COSEWIC status
The status or rank (e.g., extinct, extirpated, threatened, endangered, or rare) given to species of wildlife by the Council on the Status of Endangered Wildlife in Canada (COSEWIC).

country rocks
Generally refers to rocks invaded by igneous intrusions.

Cretaceous
The geological time period between 140 and 65 million years ago.

crinoids
Any of various marine invertebrates of the class Crinoidea, ranging in age from Ordovician to Present, which includes sea lilies and feather stars. They are characterized by feathery, radiating arms and a stem attached to a surface.

crustacean
An invertebrate animal with a hard exoskeleton and at least five pairs of jointed legs on the thorax, includes crabs, lobsters, copepods, amphipods, and isopods.

crustal plates
Major regions of the earth's crust that move relative to each other.

cryoboreal
Refers to species characteristic of the colder parts of the Boreal Zone.

cryogenic action
Disturbance of surface rock, sediment, or soil by alternate freezing and thawing; a daily or seasonal cycle in cold temperate and arctic regions.

crystalline rocks
1. Rocks consisting of minerals in an obviously crystalline state. 2. An inexact term for igneous and metamorphic rocks, as opposed to sedimentary rocks.

cuesta
An asymmetrical ridge with one steep face (an escarpment slope) and an opposite, gently inclined face (a dip-slope).

cultural landscape
A landscape that strongly reflects the past and present land uses of the people who live in it; usually includes cultivated land with patches of natural or managed land.

cupola
A small, dome-like rock formation projecting from an igneous intrusion.

current
Movement in a body of water caused by major ocean circulation or tides, by waves along shorelines, and by gravity-induced flow in rivers.

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D

decollement
The independent disruption by folding or faulting of sedimentary rocks when they slide over underlying rocks.

decomposer
An organism (often bacteria or fungi) responsible for the breakdown of organic material, releasing water, carbon dioxide, and nutrients in an ecosystem.

degradation
The decline in a soil's fertility as a result of loss of organic matter, erosion by wind or water, compaction, salinization, contamination, or acidification.

degree-days
The highest temperatures recorded for each of the days of the year at a particular place, totalled together to estimate the length of the growing season.

delta
A large alluvial deposit, roughly triangular in shape, formed at the mouth of a river.

dendritic drainage
A river or stream tributary pattern resembling the branching of certain hardwood trees.

denudation
The combined action of all the processes that wear away and lower the land, including weathering, mass wasting, stream action, and groundwater activity.

deposit
Any matter laid down; a mineral deposit is generally a natural occurrence of a mineral that is sufficiently abundant or useful to warrant exploitation.

deposition
The laying down of potential rock-forming materials; synonymous with "sedimentation."

deranged drainage
Drainage patterns associated with impermeable, poorly jointed rocks such as slate, granite, and greywacke where surface water is retained in a disorganized series of streams, lakes, and wetlands.

detrital
Referring to minerals in sedimentary rocks that were derived from igneous, other sedimentary, or metamorphic rocks.

detritivore
Animals that feed primarily on fragments of organic matter (detritus) found in soil and bottom sediments.

detritus
Dead or decaying organic matter from plants and animals.

Devonian
The geological time period between 415 and 370 million years ago.

diabase
An intrusive rock, usually occurring in dykes or intrusive sheets; characterized by lath-like feldspar minerals oriented in all directions, with darker minerals in the spaces between.

diatoms
A large and diverse division of microscopic and unicellular algae found in both fresh and salt water. The cell wall is heavily impregnated with silica, and dead cells accumulate on the seabed and eventually form deposits of diatomaceous earth. Living diatoms are abundant among the plankton and are an essential part of food chains in the sea.

differential erosion
Occurs when rocks are not uniform in character and are softer or more soluble in places; causes an uneven surface to develop from erosion or weathering.

dinoflagellates
Microscopic unicellular algae with bodies encased in tough, sculptured cellulose plates and with a whip-like flagellum that facilitates movement. Most are marine and seasonally form an important part of the plankton. Some species are so abundant that they form the basis of red tides and the associated paralytic shellfish poisoning.

diorite
A plutonic rock formed from an intrusion; salt and pepper in colour with dark and light crystals.

dip-slope
A slope of the land surface which approximately conforms to the angle at which the underlying rocks are inclined.

disjunct
An occurrence or population widely separated from the main geographic distribution.

dissected
Refers especially to plains or peneplains in the process of erosion after an uplift, resulting in an area cut into hills and valleys, or into flat uplands separated by valleys.

diurnal tide
A tide in which high water occurs only once a day at intervals of 24­27 hours.

dome
An anticline that is inclined downwards in all directions.

dominant
Refers to the principal species in a group of organisms.

downdraft
Downward movement of air as a result of convection.

drainage, soil
1. The rapidity and extent of the removal of water from soil by runoff or flow downward to underground spaces. 2. As a soil condition, the usual moisture condition of the rooting zone.

drainage basin
The land area that contributes water to a stream or lake system or directly to the ocean; also referred to as a catchment basin.

drainage divide
A boundary between adjacent drainage basins or watersheds.

droughty
Dry conditions in the ground related to long periods of dry weather.

drowned estuary
An estuary that has become submerged under the sea by geological processes.

drumlin
A smooth hill formed from deposits of glacial till; the long axis parallels the direction of flow of the former glacier.

dune
A mound, ridge, or hill of windblown sand.

dyke
1. A tabular body of igneous rock that cuts across the structure of adjacent rocks. 2. A structure with a wall to keep water out and a ditch, used to drain intertidal wetlands.

dykelands
Lands impounded by dykes and commonly used for agriculture.

dystrophic
Refers to acidic fresh water that is strongly coloured by tannins and humic derivatives; also called a brownwater lake. Typified by high oxygen consumption and deficient bottom fauna.

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E

ebb tide
The falling tide.

echinoderms
The phylum of invertebrate animals that includes starfish, sea urchins, sand dollars, and sea cucumbers.

ecology
The study of relationships between organisms and their environment.

ecosystem
The relationships among a particular assemblage of living organisms and the environment in which they live.

ecotone
An area of transition from one habitat to another.

edaphic
Factors pertaining to, or influenced by, soil conditions.

edge habitat
The area of transition from one wildlife habitat to another; an ecotone at the habitat level.

eluviation
The transportation of material in suspension or solution by the downward or lateral movement of water within soil.

embayment
An indentation in a shoreline that forms an open bay.

emergent coastline
A coast where land formerly below sea level has been exposed by crustal uplift, rise in sea level, or both.

emergent plant
A plant rooted in shallow water with much of the stem and most of the leaves above water.

encrusting algae
Species that forms a hard surface on the substrate.

end moraine
Ridge-like accumulation of till along the terminal margin of a glacier.

endemic
Confined to a specific geographic area.

eolian
Referring to the erosive action of the wind and the deposits such as sand, which are arranged by the wind. Subaerial is often used synonymously.

epibenthic
Living on the bottom surface of lakes or the ocean.

epifauna
Animals that live attached to or rove over the surface of a sea or lake bottom.

epiphyte
A plant that lives wholly but non-parasitically on other plants, usually above ground.

ericaceous
Species of woody (often evergreen) shrubs commonly associated with bog and barren habitats belonging to the Ericaceae, the blueberry family.

erosion
The wearing away and removal of material on the earth's surface by forces such as running water, wave action, moving ice, or winds.

erratic
A large rock or boulder that has been transported some distance from its source, usually by glacial action.

escarpment
A steep slope.

esker
Long, winding ridges of sand and gravel which originated within or beneath glacial ice.

estivate
A period of dormancy in cold-blooded animals during dry conditions; the metabolic rate is not decreased, but metabolism may become anaerobic, creating an oxygen depth.

estuary
A bay at the mouth of a river formed by subsidence of the land and/or a rise in sea level. Fresh water from the river mixes with the salt water of the sea, giving brackish or low salinity conditions.

euphotic zone
A zone of surface water in a sea or lake where sufficient light penetrates to allow photosynthesis to occur. The depth of the zone is limited by the clarity of the water.

eutrophication
The process of increasing the nutrient concentration of a freshwater environment. This process occurs naturally as a part of the system's successional sequence. The rate of eutrophication can be accelerated by the introduction of artificial nutrients or pollutants.

eutrophic
Referring to fresh waters: high productivity as a result of an abundant supply of nutrients.

evaporite
A rock composed of minerals derived from the evaporation of mineralized water; examples are rock salt and gypsum.

evapotranspiration
The release of water from the surfaces of plants, soil, and other objects; an essential part of the hydrological cycle.

exotic species
Species that do not normally occur in an area.

extirpated
Locally extinct.

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F

facies
1. Part of a rock body differentiated from other parts by appearance or composition; can refer to one part of a rock body, different kinds of rocks, or stratigraphic bodies. 2. A lateral subdivision of a stratigraphic unit.

fault
A fracture or zone of fractures in the earth's crust along which movement has taken place.

fault block
A mass or body of rock bounded on at least two opposite sides by faults; it may be elevated or depressed relative to the adjoining land.

faulting
Movement which produces relative displacement of adjacent rock masses along a fracture.

feldspar
A group of rock-forming minerals, considered to be the most abundant of all minerals. All are aluminum silicates of soda, potash, or lime and all are closely related in structure and composition. Feldspars are the principal constituents of igneous and plutonic rocks.

felsite
A general term used to describe a light-coloured igneous rock.

ferro-humic
Typically acidic, stony, and well-drained soils with a high organic content; associated with upland igneous or metamorphic rocks and deciduous forests.

fetch
The distance in a given direction over which wind can generate waves in water.

filter feeder
An organism that obtains its food by straining particles from the water.

first-order stream
The main, unbranched section of a river or stream.

floodplain
The land bordering a stream, built up of sediments from stream overflow and subject to inundation when the stream floods.

flood tide
The rising tide.

floral element
A component of the vegetation of a region that has a distinct assemblage of species determined by climate and site conditions. For example, in the highlands of Cape Breton Island, the association of Black Spruce, Balsam Fir, White Spruce, poplar, and birch forms a Boreal element of the Acadian Forest Zone.

fluvial
Pertaining to rivers.

fluvial deposits
All sediments, past and present, deposited by flowing water, including glaciofluvial deposits.

fluvioglacial deposits
See glaciofluvial deposit.

flux
Continuous motion or change, applied to the rate of flow in fluids.

fold
A bend in strata or any plane surface.

foliated
A layered appearance in a metamorphic rock that results from the parallel segregation of minerals.

foraminifera
Unicellular animals, mostly microscopic and marine, that secrete hard coverings composed of calcium carbonates or build them of cemented sedimentary grains. They range in age from Ordovician to Present.

forb
An herbaceous plant other than grasses; a broad-leaved herb.

foreshore
That part of the shore between the upper limit of wave-wash at high tide and the ordinary low water mark.

formation
A mappable rock unit.

fossiliferous
Containing fossils.

fossil
Any evidence preserved in rock of a once-living organism.

fragipan
A natural subsurface horizon having a higher density than the soil above; cemented when dry but showing brittleness when moist. This layer is low in organic matter and slowly permeable to water; it usually has polygon-shaped bleached cracks.

front
A sharp boundary between water masses of different properties.

frost pocket
A low-lying area of land that collects cold air flowing from surrounding elevated areas and is usually subject to early and late frosts.

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G

garnet
A family of mineralssilicates of aluminum, iron, manganese, chromium, calcium, and magnesiumoccurring as accessory minerals in a wide range of igneous rocks and as the finest crystals in some metamorphic rocks.

geochemical
Referring to alterations in the earth's crust as a result of chemical changes; focused on the distribution of the elements.

geodetic
Referring to the shape and dimensions of the earth.

geomorphology
The form of the earth, the general configuration of its surface, and the changes that take place in the evolution of land forms.

geosyncline
A large, generally linear trough that subsided deeply over a long period of time during which a thick succession of stratified sediment accumulated; the strata may have been folded into mountains. Also refers to the stratigraphic surface that subsided in such a trough.

glacial lake
A lake formed either from a basin scoured out by glacial ice or from the damming of natural drainage by glacial till.

glacial till
Nonsorted, nonstratified sediment carried or deposited by a glacier.

glaciofluvial deposit
Material moved by glaciers and subsequently sorted and deposited by streams flowing from the melting ice. These deposits are stratified and may occur in the form of outwash plains, deltas, kames, eskers, and kame terraces.

gleyed soil
An imperfectly or poorly drained soil modified by reduction, or alternating reduction and oxidation. These soils have lower chromas or more prominent mottling, or both, in some horizons than the associated well-drained soil.

gleying
A soil-forming process that operates under poor drainage conditions and results in the reduction of iron and other elements, and in grey colours and mottles.

gleysols
An order of soils developed under wet conditions and permanent or periodic reduction. These soils have low chromas or prominent mottling, or both, in some horizons.

gneiss
A coarse-grained metamorphic rock with a characteristic discontinuous layered structure and a composition generally similar to granite.

graben
A steep-sided, flat-bottomed valley formed between parallel faults.

gradient
A gradual change with distance.

granite
An intrusive rock consisting mainly of alkali feldspar and quartz. The term may be loosely used for any light-coloured, coarse-grained igneous rock.

granodiorite
An igneous rock intermediate in composition between a granite and a diorite.

graptolite
An extinct colonial organism that produced enclosing or supporting structures from a nitrogenous substance similar to fingernails.

gravel
Rock fragments 2 mm to 7.5 cm in diameter.

gravitational
Controlled by the effect of gravity.

greywacke
An impure sandstone consisting of rock fragments and grains of quartz and feldspar in a matrix of clay-sized particles.

ground cover
Those herbaceous plants, small shrubs and non-vascular plants growing beneath the tree and shrub canopy.

ground moraine
Rolling plain that has gently sloping swells, sags, or basins made of till.

groundfish
Fish that feed on or near the sea bottom.

groundwater
Water in the zone of saturation where all open spaces in sediment and rock are completely filled with water.

groundwater recharge
The intake and quantity of water added to the zone of saturation below the land surface.

groundwater seep
A spot where groundwater oozes from the earth, often forming the source of a small stream or spring.

gypsum
Commonest sulphate mineral (CaSO₄·2H₂O). Associated with halite and anhydrite in evaporite deposits.

gyre
A gyration, or circular or spiral movement, within a medium; applied to movement at the margins of ocean currents.

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H

habitat
The natural home or environment of a plant or animal.

halite
A mineral commonly associated with evaporates; rock salt.

halophyte
A plant tolerant to saline conditions, for example, in a salt marsh.

hardpan
A layer of strongly cemented material that occurs in unconsolidated sediments.

hardwood
A forestry term for deciduous, broad-leaved trees such as oak, maple, and birch and the forests they form.

headland
A high, steep-faced promontory extending into the sea.

hematite
The principal ore of iron, with the composition Fe₂0₃.

herbaceous
Descriptive of non-woody plants with no above-ground persistent parts.

herbivore
An animal which feeds on living plant material.

heterotrophic
Dependent on organic matter for food.

highwater line
The level of highest water on a shore; the high-tide line of the sea and the high-flood line of streams or lakes.

hornblende
A common member of the amphibole rock-forming minerals; usually black, dark green, or brown and found in igneous and metamorphic rocks.

hornfels
A dense, compact rock produced from slate by contact with an intrusion, especially of granite.

humo-ferric
Of soils associated with rolling plains, till features, and forest cover on coarse-textured, iron-rich parent material. Typically moderately well to rapidly well drained and very acidic, with less organic matter accumulated in the mineral layer than in ferro-humic soils.

humus
Organic detritus in soil.

hydric
Characterized by abundant moisture.

hydrocarbons
Naturally occurring hydrogen- and carbon-based complex liquids and gases created through the burial and heating of fine-grained rocks rich in organic matter.

hydrography
The mapping of the characteristics of oceans, lakes, and rivers.

hydrology
The study of the occurrence and properties of water.

hydrophytic
Refers to plants whose habitat is water or very wet places.

hydrosere
The natural zonation of vegetation at the edges of freshwater habitats.

hydrothermal
Referring to processes, solutions, rocks, deposits, and springs associated with heated or hot materials that are rich in water.

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I

IBP Proposed Ecological Site
A reserve proposed by the Canadian Committee for the International Biological Programme. An ecological reserve is a legally protected natural area where human influence is kept to a minimum. Its purpose is to preserve characteristic or regionally rare ecosystems. Ecological (Nature) Reserve sites are protected in Nova Scotia under the Special Places Act.

ice-contact drift
Any rock material deposited in contact with melting glacier ice.

ice-plucked
Moved from its original site by glacial ice.

igneous rock
One of the three main groups of rock. Igneous rocks characteristically appear crystalline and were formed by the crystallization of magma.

ignimbrite
Rock consolidated from volcanic material which was so hot that the fragments welded together.

illite
A general term that refers to the group of minerals that is abundant in sediments composed mostly or entirely of clay.

impoundment
A structure built to maintain desired water level; commonly used in waterfowl management.

infauna
Benthic animals that burrow into the substrate.

infiltration rate
The maximum rate at which soil can absorb surface water.

interbedded
Occurring between beds or lying in a bed parallel to other beds of a different material.

interglacial
Refers to the time between glaciations.

intermontane
Lying between mountains.

intertidal zone
The area between low- and high-tide marks, alternately covered by water and exposed to air during each tidal cycle.

intolerant
See shade-intolerant.

introduced species
Non-native species brought into an area intentionally or accidently by humans.

intrusion
A body of igneous rock that has forced itself into pre-existing rocks.

invertebrate
An animal without a backbone.

ironpan
A compact layer in the soil horizon with a platy structure and very low permeability that impedes drainage and root penetration.

isobar
A line drawn on atmospheric charts to connect points of equal barometric pressure and determine the locations of high and low pressure areas.

isopods
A group of crustaceans that includes wood lice.

isostatic
Related to the state of equilibrium, resembling flotation, in which segments of the earth's crust stand at levels determined by their thickness and density. During the last ice age, the ice depressed the earth's crust, upsetting the isostatic equilibrium.

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J

joint
A fracture in a rock along which there has been no movement.

Jurassic
The geological period between 210 and 140 million years ago.

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K

kame terrace
A terrace-like body of material deposited at the side of a valley by melted water that flows along the surface of a glacier.

kames
Steep-sided mounds of stratified material deposited against an ice-front.

kaolinite
A common clay mineral.

karst topography
A landscape typical of gypsum and limestone areas, where sinkholes have formed as a result of the dissolution of rocks by rainwater; narrow, crumbling ridges separate the sinkholes.

kettle hole
A bowl-shaped depression created when blocks of ice become lodged in glacial deposits and melt, leaving a depression.

knoll
1. A submerged, rounded elevation rising from the sea floor. 2. A small, rounded hill, often associated with resistant rock.

krummholz
A condition where trees growing in exposed areas exhibit an asymmetrical outline and stunted growth. Occurs as a result of extreme conditions such as high wind and salt spray.

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L

lacustrine deposits
Material deposited by or settled out of lake waters and exposed by the lowering of water levels or the elevation of land. These sediments range in texture from sand to clay and are usually varied (layered annual deposits).

lagoon
See barachois pond.

landscape
A heterogeneous land area composed of interacting systems repeated in similar form throughout. Landscapes vary in size.

landscape ecology
A study of the structure, function, and change in a heterogeneous land area composed of interacting ecosystems.

landscape element
The basic, relatively homogeneous ecological unit, whether of natural or human origin, on land at the scale of a landscape; includes matrix, patch, and corridor elements.

lava
Fluid rock, or magma, such as from a volcano or a fissure in the earth's surface; also, the same material solidified by cooling.

leaching
The process by which rain and the substances dissolved in it gradually break down and decompose rocks. Materials may be removed from soil by leaching.

lentic
Related to slow-moving water, such as in lakes and bogs.

limestone
A bedded sedimentary deposit consisting chiefly of calcium carbonate.

limnetic
Related to the environment of lakes and ponds.

lithosphere
The crust of the earth, up to 100 km.

lithostratigraphic
Consisting of stratified and mainly sedimentary rocks grouped on the basis of physical rather than biological characteristics or time.

littoral
The zone between the extreme high-tide and extreme low-tide levels in the sea; also the zone from the shore to the light-compensation level of the sea and lakes.

loam
A soil mix of coarse sand, silt, clay, and organic matter.

loess
Deposits composed primarily of windblown silt and lacking visible layers.

lotic
Related to fast-moving water, such as in most streams and rivers.

lumbricid
A general term for the oligochaete worms of the Lumbricidae which include familiar earthworms.

Luvisols
An order of soils that have a clay accumulation in the B horizon. These soils develop under forests or forest-grassland transition areas in a cool climate.

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M

macrophyte
Large plants (e.g., seaweeds, herbs, trees), in contrast to small plants such as lichens and mosses.

macrotidal
An ocean system which features a large tidal range, as in the Bay of Fundy.

magma
Molten rock material, including dissolved gases and crystals, generated within the earth and capable of intrusion and extrusion; considered the source of igneous rocks.

magnetite
Magnetic iron ore, frequently associated with igneous rocks; a black iron oxide with a metallic lustre.

marine
Associated with the sea.

marine transgression
The advance of the sea over coastal land areas as a result of rising sea levels or the subsidence of the land.

massif
A massive block of bedrock; usually a large landscape feature.

mature soil
A naturally produced soil with well-developed horizons.

meander
A loop-like bend in a stream or river that develops when a watercourse flows through level land and erodes its floodplain.

mean high or low water
The average height of the high- or low-tide mark on seashores, determined over a 19-year period.

mean sea level
The average height of the surface of the sea for all tidal stages over a 19-year period, usually determined from hourly height readings.

meiofauna
Microscopic aquatic animal life of bottom and shoreline sediments.

meltwater
Water resulting from the melting of snow or glacial ice. Glacial meltwater often forms streams and carries rock material beyond active glaciers.

meromictic (meromyxia)
The condition in permanently stratified lakes.

mesa
Flat-topped hills, or mountains, cut off on one or more sides by steep escarpments.

mesic
Refers to habitats with plentiful rainfall and well-drained soils.

mesopelagic
Related to the mid-depths of the open ocean.

mesophyte
A plant which grows in conditions of average water supply.

mesothermal
Climate with a middle temperature range, a roughly warm and cold climate, as opposed to a more extreme tropical or arctic climate.

mesotrophic
Refers to fresh waters with moderate nutrient concentrations and productivity.

Mesozoic
The geological era between 247 and 65 million years ago.

metamorphic rocks
Rocks whose physical and chemical properties have been changed by elevated temperature and pressure.

mica
A group of minerals characterized by perfect cleavage in one direction and by the thinness, toughness, and flexibility of their elastic flakes.

micro-
Refers to microscopic organisms, including animals, plants, bacteria, and fungi, that are primarily single-celled, although some colonial and multi-celled organisms are included.

microclimate
The climate of a microhabitat.

microflora
Microscopic plant life, including bacteria and some fungi.

microhabitat
The parts of a habitat an individual organism encounters in the course of its activities.

micromhos/cm
See conductivity.

midden
A prehistoric garbage dump generally found along the coast in Nova Scotia, typically consisting of a pile of shells of predominantly shellfish species and other discarded items of bone, stone, and pottery deposited during prehistoric times by aboriginal peoples.

minerotrophic
Descriptive of a habitat where nutrients are intruded from ground water flow as opposed to exclusively rainwater (ombotrophic).

mixis
The process and pattern of annual water circulation in lakes; used as a classification scheme for lakes, e.g., a monomictic lake has one regular period of water circulation during a year.

molluscs
Unsegmented invertebrate animals that possess an external or vestigial calcium carbonate shell; they include clams, snails, sea slugs, and squid.

molybdenum
A metallic element of the chromium group. It resembles iron in its white colour, malleability, difficult fusibility, and capacity for forming steel-like alloys with carbon.

monadnock
An isolated hill that stands above the general level of a peneplain; erosion remnants of the original surface.

moder
A non-matted forest humus derived from plant remains.

monzogranite
A subdivision of the granites, typically pink in colour.

mor
A well-defined matted layer of organic deposits resting on mineral soil.

moraine
Accumulations of material, mainly till, deposited directly by glaciers.

morphology
1. The form of a living organism. 2. The external forms of rocks and landscape features.

mottles
Irregularly marked spots or streaks, usually yellow or orange, but sometimes blue. Mottles in soils generally indicate poor aeration and impeded drainage.

mudstones
Dark-grey, fine-grained shales that decompose rapidly and convert to mud when exposed to the atmosphere; they include clay, silt, and siltstone.

mull
A rich soil developed under mixed forests where a suitable supply of calcium is available.

Myriapoda
A group of diverse, many-segmented, and appendaged terrestrial arthropods, including centipedes, millipedes, and isopods.

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