GLOSSARY OF TECHNICAL TERMS AND ABBREVIATIONS
The following list contains technical terms and abbreviations used in this report, as well as some additional terms commonly used in the practice of vegetation ecology. Definitions were generally adopted or paraphrased from the following sources: Allaby (1990), Allen (1990), Anderson et al. (1998), Bates and Jackson (1984), Cowardin et al. (1979), Driscoll et al. (1984), Frye (1986), Golet et al. (1993), Helm (1985), Johnson (1985), Mitsch and Gosselink (1986), Skinner and Porter (1987), and USDA Forest Service (1996).A | B | C | D | E | F | G
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ac acre(s).
acidic having a pH value < 7.0, often indicating moderate or low fertility; in practice, the following
degrees of soil acidity are recognized by the USDA: < pH 4.5 = extremely acidic; pH 4.5 to 5.0 = very strongly acidic; pH 5.1 to 5.5 = strongly acidic;
pH 5.6 to 6.0 = moderately acidic; pH 6.1 to 6.5 = slightly acidic. See also circumneutral, alkaline.
Al aluminum.
alkaline having a pH value > 7.0; in practice, the following degrees of soil alkalinity are recognized by
the USDA: pH 7.4 to 7.8 = mildly alkaline; pH 7.9 to 8.4 = moderately alkaline; soils with pH > 8.4 have not been sampled by VANHP ecologists and
probably do not occur in Virginia. See also acidic, circumneutral.
allelopathic of or pertaining to the release by an organism of a chemical substance that acts as an
inhibitor to the germination or growth of another organism.
alluvial of or pertaining to deposition of sediment by a stream.
alluvial fan a body of alluvium forming a segment of a cone that radiates downslope from a point where a stream emerges from a
narrow valley onto a less sloping surface (e.g., at the foot of a mountain).
alluvium unconsolidated sand, silt, clay, or gravel deposited by running water; see also colluvium.
amphibolite a metamorphic, mafic rock composed predominately of hornblende and other silicate
minerals rich in iron and magnesium. See also mafic.
annual a plant species that completes its life-cycle in one growing season.
aspect the direction a slope faces (e.g., a north aspect).
B boron.
backswamp a depressed area of a floodplain between the elevated levee bordering a channel and a
valley side or terrace.
bar an elongated, ridge-like landform generated by waves and currents, and composed of sand, gravel,
or other alluvial materials; usually runs parallel to the shore with water on two sides.
barren an exposed, usually rocky, non-forested habitat in which shallow soils and drought-stress limit
the establishment and growth of woody plants; typically dominated by warm-season perennial grasses.
basal area the cross-sectional area of a tree at breast height; extrapolated to a larger area, basal area is
an estimated measure of how much of a site is occupied by trees.
base cation the positively-charged ions of substances (e.g., calcium and magnesium) that in solution
can bind and remove hydrogen ions or protons.
basic as applied to soils, having high levels of base cation (e.g., calcium, magnesium) saturation,
typically indicating high fertility; as applied to rocks, having high concentrations of iron, magnesium, and calcium.
basin wetland a depression wetland with no or limited surface outlet.
biomass the total weight of all living organisms in a biological community; in vegetation science, usually the total weight of
all above-ground plant parts.
bog in strict usage, an ombrotrophic peatland with organic soils > 40 cm deep; more generally (in the
southeastern United States), any non-forested, oligotrophic wetland with groundwater-controlled hydrology. See fen, peatland, oligotrophic, ombrotrophic,
and see Weakley and Schafale (1994) for additional discussion.
boreal of or pertaining to subpolar and cold-temperate areas.
boulderfield a sheet of coarse, loose, rock fragments mantling a slope; a collective term including talus, scree, block fields,
and bouldery colluvium.
brackish of or pertaining to water having salt concentrations between 0.5 and 30 parts per thousand;
collective term encompassing oligohaline, mesohaline, and polyhaline regimes (see below).
breached foredune an ocean-fronting dune that has been partly eroded or removed by ocean winds and
water.
bryophyte a non-vascular green plant; includes mosses, hornworts, and liverworts. See non-vascular.
Ca calcium.
calcareous having high levels of calcium carbonate; applied to both soils and rock; in practice, DCR-
DNH ecologists consider soils with calcium levels of >1200 parts per million to be calcareous.
calciphile a plant restricted to or particularly characteristic of calcareous substrates.
carbonate rock collective term for limestone and dolomite.
categorical variable a property or quantity that is represented by discrete units, e.g., geologic rock
types or vegetation types, rather than by a gradient.
CEC cation exchange capacity, i.e., the total amount of exchangeable cations that a particular soil or
material can bind at a given pH; exchangeable cations are held mainly on the surface of colloids of clay or humus; measured in milligrams per 100 g of soil.
circumneutral having a pH ~ 7.0; in practice, soils with pH 6.6 to 7.3 are considered circumneutral.
See also acidic, alkaline.
channery thin, flat fragments of shale, limestone, or other sedimentary rocks < 15 cm (6 in) in
diameter.
charnockite a granitic rock containing abundant pyroxene, a dark silicate mineral.
clone a group of genetically identical individuals derived from a common ancestor by asexual division;
applied in vegetation science to a colony or group of plants generated by vegetative sprouting from underground rootstocks. See rhizomatous.
clonal producing clones by vegetative sprouting from underground rootstocks; rhizomatous.
cluster analysis a method of numerical classification that evaluates the similarity of quantitative
samples and, through an interactive statistical process, fuses into clusters those samples that are
most similar; different types of cluster analysis have been used in vegetation ecology: VANHP ecologists use agglomerative-hierarchical cluster
analysis, which starts with each sample in its own group and progressively fuses them into larger groups.
cm centimeter(s).
cohort a group of individuals of the same age or generation.
collinearity a numerical problem that results when variables in a regression model are highly
correlated.
colluvial of or pertaining to colluvium.
colluvium unconsolidated earth materials deposited on steep slopes by direct gravitational action and local unconcentrated run-off.
See also alluvium.
community as applied to plants, any unit of vegetation regardless of rank or development; an aggregation of plants on the landscape;
in broader terms, any assemblage of organisms that co-occur and interact.
community type an abstract unit of vegetation representing concrete plant communities sharing a similar structure and floristic composition, and occurring
under similar environmental conditions; more or less equivalent to the "association" used in traditional phytosociological studies and the National
Vegetation Classification.
composite a plant of the Aster or Sunflower Family (Asteraceae).
continuous variable a property or quantity that could be any conceivable value within an observable or
measurable range.
cover the percentage of the ground covered by the vertical projection of above-ground plant parts.
crustose lichen - a lichen adhering closely to, and difficult or impossible to separate from, its substrate;
crustose lichens abundantly cover most exposed rock outcrops. See lichen.
Cu copper.
dbh diameter at breast height (1.4 m [4.6 ft] above the ground); the standard position at which woody
stems are measured in forestry procedures.
dendrogram a tree-like graphic that depicts the results of cluster analysis.
density the number of plants per unit area; used more specifically in vegetation ecology as a measure of
the number of woody stems = than a specified measure in diameter at breast height per hectare.
detritus rock debris or litter formed from fragments of dead, organic material (e.g., leaf litter or pieces
of wood).
Devonian a period of the Paleozoic era, following the Silurian and preceding the Mississippian, from
about 400 to 345 million years ago.
diabase an intrusive, mafic, volcanic rock composed largely of plagioclase feldspar and dark silicate minerals; similar to, and intermediate
in texture between, gabbro and basalt.
dip slope a side slope determined by and approximately aligned with the angle of the underlying
bedrock plane.
diurnally flooded alternately flooded and exposed by tidal water on a daily basis.
dolomite a sedimentary rock composed of calcium and magnesium carbonate. See also limestone.
dominant of or pertaining to an organism or taxon that by its size, abundance, or coverage exerts considerable influence on a communitys
biotic and abiotic conditions.
dry-mesic intermediate between dry and moist but well drained; submesic.
duff the matted, partly decomposed organic surface layer of forest soils.
dummy variable a binary variable of 0s and 1s, which is one if the observation belongs to a category
and zero if it does not.
ecosystem a complete interacting system of organisms and their environment, applicable at any spatial
scale.
ecotone a transitional area where characteristics of adjacent communities or environments are intermingled or gradational.
edaphic of or pertaining to the influence of soils on living organisms, particularly plants.
embayment a broad ocean inlet or estuarine river and the landforms enclosing it.
endemic geographically restricted; a species or taxonomic group restricted to a particular
geographic region.
environmental gradient - a spatially varying aspect of the environment (e.g., elevation, slope position,
soil pH) that is expected to be related to species composition.
environmental variable - a measure of the environment that is presumably related to an environmental
gradient; environmental variables can be continuous, or they can be represented by ordinal or dummy variables. See continuous variable, dummy variable,
environmental gradient, ordinal variable.
ephemeral seepage brief groundwater outflow resulting from precipitation.
ericaceous of the Heath Family (Ericaceae). See ericad.
ericad a plant of the Heath Family (Ericaceae); for example, blueberries (Vaccinium spp.), rhododendrons (Rhododendron spp.),
and mountain-laurel (Kalmia latifolia).
estuarine pertaining to a body of water that has a connection (open, partly obstructed, or sporadic) to
the ocean and where fresh water from overland drainage is mixed with oceanic salt water; usually characterized by tidal activity; the Estuarine System,
as defined in this report, extends upstream to the inland limits of tidal flooding, thus including a zone of strictly freshwater tidal habitats on
coastal rivers.
eutrophic enriched with nutrients; applied both to naturally fertile environments and to those that have been enriched by anthropogenic
disturbances.
exotic an introduced, non-native species.
Fe iron.
fen in strict usage, a minerotrophic, enriched peatland with organic soils > 40 cm deep; more generally
(in the southeastern United States), applied to similar wetlands lacking, or with only superficial, organic soils. See bog, minerotrophic, peatland,
oligotrophic, and see Weakley and Schafale (1994) for additional discussion.
fibric peat partially decomposed organic material whose original structure is still visible.
flora all the plants that make up the vegetation of a specified area. See also vegetation.
floristic of or pertaining to the flora of an area and the geographic patterns of distribution represented by its taxa. See also floristics.
floristics the study of a flora and the geographic distributions of its taxa.
fluvial of, pertaining to, or produced by rivers.
floodplain a nearly level alluvial plain that borders a stream and is subject to inundation (non-tidal) under flood-stage conditions.
foliose lichen - a lichen typically lying flush to its substrate, but removable such that the ventral surface is
visible; foliose lichens are attached to rocks and other substrates by numerous fine structures called rhizines; see lichen.
forb a broad-leaved herbaceous plant.
forest vegetation dominated by trees (= 6m [20 ft] tall) producing a more or less closed canopy,
typically with 60-100% cover; some forests may temporarily have < 60% canopy cover
following disturbances such as windthrow, disease, etc.
freshwater of or pertaining to water with salt concentrations of < 0.5 parts per thousand.
fruticose lichen a lichen that grows erect or pendent, with thalli that have no clearly distinguishable
upper and lower surfaces; includes species that are branched and shrubby, as well as those that form unbranched stalks. See lichen.
ft foot (feet).
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gabbro an intrusive igneous, mafic rock composed primarily of plagioclase feldspar and pyroxene.
geomorphic of or pertaining to processes that change the form of the earth (e.g., volcanic activity, running waters, glaciers).
gneiss a metamorphic, foliated rock composed predominately of feldspar and showing color banding or
alignment of mineral grains.
graminoid grasses and grass-like plants (e.g., sedges and rushes).
granite an igneous rock composed predominately of feldspar and quartz.
granodiorite a granitic rock composed of plagioclase feldspar, quartz, and various dark silicate minerals, including hypersthene, augite,
biotite, hornblende, and garnet; contains a lower proportion of silica than true granite.
greenstone a metamorphosed basalt composed predominantly of plagioclase, chlorite, epidote, and albite.
groundwater water occurring below the earth's surface in bedrock and soil.
ha hectare(s).
halophyte a plant restricted to or particularly characteristic of saline environments.
hardpan a dense, clay subsoil layer that impedes internal drainage and root penetration.
heath - a plant of the Heath Family (Ericaceae); an Ericad; for example, blueberries (Vacciniumspp.), rhododendrons (Rhododendron spp.), and
mountain-laurel (Kalmia latifolia).
herb a vascular plant lacking woody tissue at or above ground level.
herbaceous vegetation vegetation dominated by herbs having = 5 % total cover; such vegetation with
herb cover from 5 to 25% is referred to as sparse herbaceous vegetation.
herbivory the consumption of plants by animals.
hibernacula overwintering den sites used by animals such as bats, snakes, and insects that hibernate
in a state of torpor.
Holocene an Epoch of the Quaternary Period of geologic time, from approximately ten thousand years
ago to the present.
humus decomposed organic matter that has lost all trace of the structure and composition of the
vegetable or animal matter from which it was derived.
hydric wet.
hydromorphic structurally adapted for life in aquatic habitats.
hydroperiod the specific flooding cycle of a wetland habitat; usually applied to the
more or less regular periodicity of seasonally flooded wetlands.
hydrophytic pertaining to plants or vegetation adapted to wetland environments.
hyperhaline of or pertaining to water with salt concentrations > 40 parts per thousand, or to wetland
soils that contain > 15% exchangeable sodium, a level that interferes with the growth of most plants; usually applied to Salt Flats ("salt pannes"),
depressions that accumulate salt through evaporation of tidal inputs.
igneous formed by solidification of magma within the earth's crust or of lava on the surface.
in inch(es).
indirect gradient analysis an analytical technique in which gradients are unknown a priori, and are
inferred from species composition data; in vegetation ecology, usually performed using an ordination technique.
intertidal zone the zone between average low tide and average high tide in an estuary.
interfluve the elevated area between two drainageways that sheds water to them.
intermittently exposed substrate usually flooded, but exposed occasionally and without detectable
seasonal periodicity.
intermittently flooded - substrate usually exposed, but surface water present occasionally and without
detectable seasonal periodicity.
interstice an intervening space or crevice.
interstitial of or pertaining to interstices.
irregularly flooded - flooded by tidal water less often than daily but at least once annually.
landslide bench - a sag between resistant and less resistant sedimentary bedrock units in areas of
catastrophic slope failure and landsliding; expressed physiographically as a sub-level, mid-slope area.
Jurassic the second period of the Mesozoic era (following the Triassic), from approximately 190 to 135
million years ago.
K potassium.
km kilometer(s).
leeward on or toward the side sheltered from the wind.
levee a low ridge or embankment of sand and coarse silt, built up by a stream on its flood
plain and located adjacent to its channel.
liana a woody vine.
lichen a symbiotic association between a fungus and one or more species of algae and/or blue-green algae; although not based on genetic
relationships, lichen species, for the aid of identification, are divided into foliose, fruticose, crustose, and umbilicate groups based on their
growth strategies. See crustose lichen, foliose lichen, umbilicate lichen.
limesand sand containing significant quantities of calcium carbonate derived from finely weathered
shell material.
limestone a sedimentary rock composed predominantly of the mineral calcium carbonate (calcite). See also dolomite.
lithologic of or pertaining to the physical characteristics of a rock.
lithology the description of rocks on the basis of physical characteristics such as color, mineralogical
composition, and grain size.
lithophyte a vascular plant confined to or particularly characteristic of rock habitats (outcrop crevices, shelves, ledges).
lithophytic of or pertaining to lithophytes.
liverwort - a nonvascular, chlorophyll-containing plant closely related to mosses and hornworts, but differing in reproductive structures;
liverworts have two dominant growth forms, one which resembles moss with overlapping leaves, the other forming prostrate leafless bodies. See non-vascular.
m meter(s).
macroinvertebrate an animal lacking a backbone (invertebrate) and visible without the aid of
magnification.
mafic geologically, containing large amounts of dark-colored silicate minerals rich in magnesium and
iron, e.g., pyroxene, amphibole, and biotite mica; examples include igneous and metamorphic rocks such as amphibolite, basalt, diabase, gabbro, and
greenstone; also applied to soils with high levels of magnesium and iron that are derived from these formations. See also ultramafic.
magnesiophile - a plant restricted to or particularly characteristic of magnesium-rich substrates, e.g., soils
derived from dolomite or mafic rocks.
MANOVA see multivariate analysis of variance.
marine of or pertaining to the ocean and its waves and currents; the Marine System, as defined in this
report, extends from the outer edge of the continental shelf shoreward 1) to the landward limit of tidal inundation on beaches and 2) to the oceanward
limit of water bodies with salinities < 30 parts per thousand.
maritime living or situated near an ocean; of or pertaining to an environment under oceanic influences.
marl lime-rich clay containing a high proportion of soft calcium carbonate.
marsh a eutrophic, non-forested wetland characterized by emergent herbaceous plants and a hydrologic
regime of overland or tidal flooding. See eutrophic.
meander one of a series of sinuous loops, with sine-wave form, in the course of a stream channel.
mesic of intermediate moisture conditions (i.e., moist and well-drained).
mesohaline of or pertaining to water with salt concentrations from 5 to 18 parts per thousand.
mesophyte a plant characteristic of mesic environments.
mesophytic of or pertaining to plants or vegetation adapted to environments of intermediate moisture conditions.
Mesozoic an Era of geologic time, from the end of the Paleozoic to the beginning of the Cenozoic, or
about 225 to 65 million years ago; includes the Triassic, Jurassic, and Cretaceous periods.
metabasalt metamorphosed basalt, a fine-grained igneous rock composed largely of plagioclase feldspar, pyroxene, and volcanic glass.
See greenstone, a metabasalt underlying extensive portions of the northern Blue Ridge and western Piedmont foothills.
metagrawacke - a dark gray, metamorphosed sandstone consisting of angular grains of quartz, feldspar,
and various rock fragments, set in a compact, clayey matrix having the general composition of slate.
metamorphic altered in mineral composition, chemical composition, and structure by heat, pressure, and hot fluids at some depth below the
earth's surface; applied to rocks of igneous and sedimentary origin.
metasedimentary consisting of sedimentary rock that shows evidence of having been subject to
metamorphism; examples include quartzite (= metasandstone) and metasiltstone.
metasiltstone metamorphosed siltstone. See siltstone.
metavolcanic consisting of metamorphosed rocks of volcanic origin, e.g., metabasalt.
Mg magnesium.
mi mile(s).
microclimate the local climate of a small site; this may vary from the climate of the larger, surrounding area due to aspect, tree cover,
elevation, wind exposure, and other local factors.
microhabitat within a habitat, a subdivision or precise location that has distinctive environmental
characteristics; e.g., a tree-base hummock in a flooded swamp.
microtopography the fine-scale variation in topography within a habitat; e.g., the pattern of vertical rock faces, shelves, and
crevices on a cliff.
minerotrophic receiving water that has passed through mineral soil; usually applied to groundwater- fed, enriched peatlands (true fens).
See fen, ombrotrophic.
Mississippian a period of the Paleozoic era, following the Devonian and preceding the Pennsylvanian,
from about 345 to 320 million years ago.
Mn manganese.
monadnock an isolated hill or range of hills, resulting from erosion of the surrounding terrain; usually
underlain by relatively resistant rocks.
monospecific consisting wholly or largely of a single species.
moss - a nonvascular chlorophyll-containing plant closely related to liverworts and hornworts, but differing in reproductive structures.
See non-vascular.
mudstone a sedimentary rock formed by hardening of silt and clay in approximately equal proportions.
multivariate analysis of variance a technique which simultaneously tests differences between more
than one dependent variable by relating variation to a set of independent variables.
multivariate technique any analysis that simultaneously examines the behavior of more than one
dependent variable.
muscovite a mineral of the mica group that is common in gneisses and schists; also known as white
mica.
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Na sodium.
NMDS see non-metric multidimensional scaling.
non-metric multidimensional scaling an ordination technique, based on indirect gradient analysis, that
maximizes, to the extent possible, the rank-order (i.e., non-parametric) correlation between inter-sample dissimilarity and inter-sample distance in
ordination space.
non-vascular lacking a structural system of tissue (xylem and phloem) that conducts water and soluble
nutrients; non-vascular plants include mosses, lichens, and liverworts.
ombrotrophic of or pertaining to wetlands, usually peatlands, that are fed by rainwater.
oligohaline pertaining to water with salt concentrations from 0.5 to 5.0 parts per thousand.
oligotrophic infertile. See also eutrophic.
ordinal variable a property or quantity that may be represented by an ordered or ranked scale of values
that denote relative magnitude.
ordination a multivariate technique that arranges vegetation samples in relation to each other based on
compositional similarity and relative species-abundances. Ordination procedures summarize
multidimensional data in a reduced coordinate system, extracting those axes that explain the most variation in the data.
See non-metric multidimensional scaling.
Ordovician the second earliest period of the Paleozoic era, following the Cambrian and preceding the
Silurian, from about 500 to 440 million years ago.
orogeny the process of mountain formation.
overstory the uppermost layer of trees forming the canopy of a forest or woodland.
oxbow a closely looping stream meander having an extreme curvature such that only a neck of land is
left between the two parts of the stream.
p the probability of observed data if a null hypothesis is true; if the p-value is small (typically, < 0.05),
then the result is considered statistically significant.
P phosphorus.
palustrine of or pertaining to non-tidal wetlands; the Palustrine System, as defined in this
report, includes all non-tidal wetlands dominated by woody plants and herbaceous emergents.
patch-dominant a species that exerts dominance by forming dense but spatially discrete colonies; such
a species typically varies from abundant to completely absent within a given habitat.
pathogen an organism that causes disease in another organism.
peat an organic soil or deposit, often formed under anaerobic conditions associated with waterlogging.
peatland a wetland with organic soils > 40 cm deep.
Pennsylvanian a period of the Paleozoic era, following the Mississippian and preceding the Permian,
from about 320 to 280 million years ago.
perched water table groundwater whose surface, while normally well below ground, is periodically or
seasonally elevated close to or above the soil surface.
perennial a plant species with a life-cycle that lasts at least two growing seasons.
periglacial specifically, of or pertaining to an area adjacent to a contemporary or Pleistocene glacier; more generally, any environment where the action of freezing and thawing is currently, or was during the Pleistocene, the dominant surface process.
pH a value on the scale 0 to 14 that gives a measure of the acidity or alkalinity of a medium. See also acidic, alkaline, and circumneutral.
phenology the study of periodicity of leafing, flowering, and fruiting in plants; leaf phenology refers
broadly to the habit and duration of foliage.
phyllite a metamorphosed sedimentary rock intermediate in grade between slate and mica schist;
minute crystals of sericite mica impart a silky, silvery sheen to the cleavage surfaces.
physiognomic of or pertaining to vegetative form and structure.
physiognomy the form and structure of vegetation.
physiographic province a landform region; an area delineated according to similar terrain that has been
shaped by a common geologic history. Geographers and geomorphologists characterize physiographic provinces by their relative elevation, relief,
lithology, and geologic structure. Specific types of landforms or other geologic features are found within a given province as a consequence of the
region's history of rock formation, deformation, and erosion. It is often possible to subdivide the provinces into subregions based on the distribution
pattern of these features.
phytogeography the study of the geographic distribution of plants and vegetation , with an emphasis on
environmental determinants of distribution.
Pleistocene the first Epoch of the Quaternary Period of geologic time, from approximately ten thousand to two million years ago.
pocosin an ombrotrophic, saturated peatland supporting pyrophytic woodland vegetation dominated by
pond pine (Pinus serotina) and various evergreen shrubs. See ombrotrophic, pyrophytic.
polyhaline of or pertaining to water with salt concentrations from 18 to 30 parts per thousand.
pyrophytic of or pertaining to plants or vegetation adapted to environments in which fire is an
important ecological process.
quartzite metamorphosed sandstone. See sandstone.
r correlation coefficient, a number which reflects the strength of the relationship between two variables;
this value varies between -1 (for a perfect negative relationship) and +1 (for a perfect positive relationship).
r2 correlation coefficient squared, a value between 0 and 1 known as the coefficient of determination;
indicates the proportion of variance in a dependent variable that can be explained by its dependence on independent variables. In cluster analysis,
the r2 cut-off level is a measure of within-cluster variance, which increases as more units are added to a cluster (i.e., r2 = 1 when all samples
are in their own cluster, and r2 = 0 when all samples are in one cluster).
recruitment generally, the trees involved in natural supplementation of a forest stand; more
specifically, trees that have entered a particularly category (age or size class) during a given period.
refugia sites where plants or vegetation that formerly had much wider distributions have survived
locally through periods of unfavorable conditions in a region.
regolith all unconsolidated earth materials above solid bedrock.
regularly flooded alternately flooded and exposed by tidal water on a daily basis.
relict an organism or community that has survived while related ones have become extinct; often
applied to plants or vegetation that formerly had much wider distributions and have survived locally through periods of unfavorable conditions in a region.
rhizomatous having a horizontal, creeping, perennial rootstock that produces smaller roots and
vegetative shoots.
rhyolite a volcanic rock composed predominantly of quartz and feldspar.
rill a small streamlet or rivulet.
riparian of the area beside a stream, especially a river.
riverine of or pertaining to waters enclosed by channel banks; the Riverine System, as defined in this
report, includes all non-tidal wetlands and deepwater habitats contained within stream channels, except those dominated by woody plants or
herbaceous emergents.
ruderal vegetation vegetation resulting from succession following anthropogenic disturbance of an
area; generally characterized by unnatural combinations of species (primarily native though including small to substantial numbers of exotics) and
relatively short persistence in the absence of additional disturbance.
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saline in common parlance, pertaining to or characterized by salt; in strict, formal usage, this term is applied only to terrestrial
and inland wetland environments, whereas the term haline is applied to environments under the influence of oceanic salts.
sandstone a medium-grained sedimentary rock composed of rounded sand grains cemented together by silica, iron oxide, or calcium carbonate.
saturated wet for extended periods during the growing season, but never or rarely flooded by surface
water; usually applied to wetlands maintained by seepage inputs or perched water tables.
savanna a sparse woodland with little or no understory and a dense, graminoid-dominated herb layer.
scalar a synthetically derived measure of the environment that functions as a pseudo-continuous or
ordinal variable; examples include Topographic Relative Moisture Index and Relative Slope Position (see Fleming 2002). See continuous variable,
environmental variable, ordinal variable.
schist a metamorphic rock containing abundant, visible platy minerals (e.g., mica), giving it a pronounced foliation and cleavage.
scrub vegetation dominated by shrubs. See shrubland.
seasonally flooded surface water present for extended periods during the growing season, but absent by
the end of the growing season in most years.
sedimentary formed from the deposition and compression of mineral and rock particles, and sometimes
material of organic origin; examples of sedimentary rocks include sandstone, shale, and limestone.
seep a small area of groundwater discharge, either non-forested or shaded by trees rooted in adjacent,
upland habitats; seeps generally support characteristic herbaceous wetland species but are too small or narrow to support hydrophytic woody vegetation.
seepage swamp a large area of groundwater discharge supporting wetland forest or shrubland
vegetation.
semipermanently flooded surface water present throughout the growing season in most years except during droughts.
seral of or pertaining to an intermediate or transitional stage in plant succession.
serotinous cone the cone of a pine (e.g., pitch pine, Pinus rigida) that remains closed for a period of
time, sometimes years, following maturation; the opening of such cones are often triggered by the heat of fires; a reproductive adaptation that
ensures seed dispersal under optimal conditions.
serpentinite a metamorphic, ultramafic rock composed primarily of serpentine, a magnesium silicate
mineral indicative of low-grade metamorphism.
shale - a fine-grained sedimentary rock composed of mud, silt, and clay grains and characteristically splitting into thin layers.
shrubland vegetation dominated by woody plants < 6m (20 ft) tall and having = 5% total cover;
such vegetation with shrub cover from 5 to 25% is referred to as a sparse shrubland.
siltstone a sedimentary rock formed by hardening of silt particles intermediate in size between clay and sand.
Silurian a period of the Paleozoic era, following the Ordovician and preceding the Devonian, from
about 440 to 400 million years ago.
slate a fine-grained metamorphic rock that splits cleanly into thin slabs; metamorphosed shale.
slough a linear depression or meander channel in a floodplain, usually with a seasonally or
semipermanently flooded hydrology.
snag a standing dead tree.
soapstone a massive, metamorphic, ultramafic rock composed primarily of talc and serpentine.
sp. a species.
spring ephemeral a plant that completes its reproductive cycle early in the growing season, typically before or during the period in
which trees leaf out; such species usually die back and become dormant during unfavorable summer months when habitats are characterized by high
temperatures and deep shade.
spp. species (plural).
ssp. subspecies, a taxonomic rank below species.
stratigraphy the arrangement of bedrock strata, particularly their geographic position and
chronological order of sequence.
stratum a distinct vertical layer of vegetation defined by relative height (e.g., overstory, understory)
and/or by a specific range of heights (see p. 20).
sub-canopy the understory tree layer immediately below the overstory.
submesic somewhat moist but well drained, or intermediate between dry and moist; dry-mesic.
sub-shrub a low, slightly shrubby plant, usually dying back annually to a woody base; such plants often
are treated as herbs; examples include Chimaphila maculata (spotted wintergreen) and Hypericum hypericoides ssp. multicaule (St. Andrews cross).
subxeric somewhat dry and drought-prone; intermediate between submesic and xeric.
succession natural change in the composition and structure of a plant community over time in the absence of disturbance.
successional of or pertaining to the process of succession.
surface substrate a collective term for the abiotic materials (e.g., leaf litter, rocks, dead wood) that
constitute the ground cover of a site.
swale a slight depression in a generally level landscape; or, in the case of an interdune swale, a long, narrow, trough-like depression
between two beach ridges.
swamp a forested or shrub-dominated wetland with a hydrologic regime of seasonal, semipermanent, permanent, or tidal flooding;
contrast with seepage swamp, which has a saturated, groundwater-controlled hydrology. See seasonally flooded,
semipermanently flooded.
TBS see total base saturation.
temporarily flooded surface water, usually flowing, present for brief periods during the growing
season, but water table normally lies well below the surface; applied to floodplain wetlands.
terrace one of a series of platforms flanking and more or less parallel to a stream channel; originally formed near the level of the
stream and representing the dissected remnants of an abandoned floodplain, stream bed, or valley floor produced during a former stage of erosion or deposition.
terrestrial of or pertaining to upland (non-wetland) environments.
Tertiary the first period of the Cenozoic Era of geological time, from approximately two million to 65
million years ago.
toe slope the geomorphic unit that forms the outermost, gently inclined surface at the base of a hillslope.
total base saturation the extent to which the exchange sites of a soil are occupied by exchangeable
base cations (e.g., calcium and magnesium), expressed as a percentage of the total cation exchange capacity. See CEC.
travertine limestone deposited around caverns, or in hot springs and waterfalls.
Triassic the earliest period of the Mesozoic Era, from approximately 213 million to 248 million years
ago.
TRMI Topographic Relative Moisture Index, a synthetic environmental variable used to quantitatively
estimate potential site moisture.
ultramafic derived from igneous rocks with little feldspar and large amounts of mafic minerals;
compared to mafic rocks, ultramafic rocks contain larger quantities of heavy metals and were formed deeper in the earths mantle; examples include serpentinite,
soapstone, and talc-tremolite schist. See also mafic.
umbilicate lichen - a leaf-like lichen attached to rocks by a single cord; umbilicate lichens, especially those of the genus Umbilicaria,
are often referred to as rock tripes.
understory collective term for the small trees and shrubs growing beneath the canopy in a forest or
woodland.
var. variety, a taxonomic rank below species.
vascular having a structural system of tissue (xylem and phloem) that conducts water and soluble
nutrients; vascular plants include ferns and flowering plants.
vegetation the plant life of an area, including its floristic composition, structure, biomass, and phenology.
See also flora.
woodland vegetation dominated by trees (= 6m [20 ft] tall) producing an open canopy,
typically with 5-60% cover; such vegetation with canopy cover from 5 to 25% is referred to as a sparse woodland; some woodlands may have > 60%
canopy cover following elimination or reduction of natural disturbances (e.g., fire).
xeric dry; drought-prone.
xerophyte a plant or vegetation type adapted to dry environments.
Zn zinc.
