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VIRGINIA NATURALLY

Glossary

Glossary

"A" horizon - the surface layer or topsoil; the dark and generally loose and crumbly layer which contains higher amounts of organic matter

acre - a piece of land containing 43,560 square feet. (example: a parcel 150 feet wide and 290.4 feet long is one acre)

adaptation - the process of making adjustments to the environment

aggregates - hard materials such as sand, gravel, or crushed stone, used for mixing with a cementing material to form concrete; or used alone as fill

air exchange - process by which plants can remove chemicals from the air and produce "clean" oxygen

air pollution - any visible or invisible particle or gas found in the air that is not part of its normal composition

aquaculture - raising fish on a farm

aquifer - geologic formation which contains usable amounts of groundwater that can be accessed from a well or spring


"B" horizon - subsoil; a light colored, dense layer which contains higher amounts of clay

best management practice (BMP) - a method of working the land that minimizes the impacts of disturbance and thus conserves soil and water resources

biological diversity (or biodiversity) - the variety and complexity of species present and interacting in an ecosystem and the relative abundance of each

biodegradable - capable of being broken down by air, water, and bacteria

biomass - the total weight (mass) of all living matter in a particular habitat or area

biota - the animal and plant life of a region or period

biotechnology - the use of technology to create bigger and better plants and animals


"C" horizon - parent material

cambium - a thin layer of living dividing cells just under the bark of trees; this layer gives rise to the tree's secondary growth

carrying capacity - a wildlife management term for an equilibrium expressed by the availability of habitat components and the number of animals in a given area. In general ecological usage, carrying capacity is the dynamic equilibrium established between a life form and its environment. It is frequently expressed as a number indicating the population of any animal a given area can support. Carrying capacity varies throughout the year. The population number varies from year to year, depending upon conditions within the habitat such as rainfall. There may be a difference between the ecological carrying capacity of a given area and the cultural carrying capacity of an area. The cultural carrying capacity is the number of a given species of animal that the human community will tolerate. This number is generally lower than the actual carrying capacity of the land.

cellulose - a complex carbohydrate that constitutes the chief part of the cell walls of higher plants and yields fiber for many products

clear-cut - a method of harvest in which all trees in a given area are removed, and the area is then replanted or allowed to regenerate; this method is usually used with shade-tolerant species

closed-loop recycling - the act of collecting, remaking, and purchasing the remade material which can be used and re-collected again

compost - partially decomposed organic matter

compound leaf - a leaf that is subdivided into many leaflets; a leaf that is comprised of a single leaf blade is a "simple leaf"

conifer - a plant that bears its seeds in cones

conservation - the care and protection (wise use) of natural resources from loss and waste. (example: actions that prevent soil erosion)

contaminant - an item that is not recyclable found in a load of recyclables, making the load unable to be recycled

contour farming - strips of plowed land located next to strips of grassland; a practice used to control water run-off and soil erosion


deciduous (adj.) - describes a plant that periodically (typically in autumn) loses all its leaves; most North American broadleaf trees are deciduous; a few conifers, such as the larch and cypress, are also deciduous

diversity - variety; an ecosystem must contain a variety of plant and animal life to be healthy. An ecosystem with few species is not as healthy or dynamic as an ecosystem with a diversity of species.

dump - location where garbage is just dumped; not to be confused with a sanitary landfill where garbage is processed properly


ecology - interrelationships between organisms and their environment

ecosystem - a natural unit that includes living and nonliving parts interacting to produce a stable system in which the exchange of materials between the living and nonliving parts follow closed paths; all living things and their environment in an area of any size will all be linked together by energy and nutrient flow

eelgrass - a rooted underwater grass type plant

emissions - electrons discharged into the air from a surface

environment - the conditions under which an organism lives

enviroshopping - a strategy used to make wiser shopping decisions that results in less trash being produced

erosion - wearing down or washing away of soil and land surface by the action of wind, water, or ice

escarpment - a long cliff or steep slope facing in one direction that separates two relatively level surfaces; produced by erosion or faulting


feed - food given to farm animals for growth, energy, and nourishment. Example: hay, corn, and oats.

fertilizer - plant food applied to the soil for plants to use for nourishment and growth

fiber - plant or animal products used to make clothing, paper, homes, and furniture. Example: cotton, timber, and wool


geology - the study of the earth and its history, and the processes and forces which are constantly changing its face

grass strips - strips of grass between cultivated areas that are left to control water run-off

groundwater - water stored under ground that most people depend upon to drink


habitat - the arrangement of food, water, shelter or cover, and space suitable to an animal's needs. It is the "life range" which must include food and water as well as escape cover, winter cover, and cover to rear young.

hardwood - a deciduous or broadleaf tree; also applies to the wood from such trees

hazardous material - an item that is harmful to the environment

heartwood - the older, harder, nonliving central portion of wood of some trees that is usually darker, denser, less permeable, and more durable than the surrounding sapwood; many trees do not form a true heartwood

horizon - a layer of soil with similar physical and chemical properties


igneous - describes a rock or mineral that solidified from molten or partly molten material

indoor air pollution - an invisible or odorless form of gaseous chemicals emitted from furnishings and objects and trapped in poorly ventilated buildings; includes tobacco smoke, dust, paint thinner, cleaners, pesticides, radon gas, smoke from wood burning fireplaces, and chemicals from personal care products; chemicals used in the manufacturing of furniture, paint, carpeting, ink on printed materials, plastic, and dry cleaning solutions that are emitted and can cause headaches, drowsiness, and irritation of the eyes, nose, and throat

infiltration rate - the rate that rainfall soaks into the soil surface

interdependencies - the relationships of wildlife to one another and with the various elements of their environment


karst - describes the topography formed over certain rock types by dissolution. It is characterized by sinkholes caves, and underground streams


latex - a sap from trees; used to make rubber or plastic products such as tires, gloves, and paint

leaching - the loss of materials caused by water carrying them deeper into the soil profile

leaf litter - a layer of decaying plant matter (such as leaves, twigs, grasses, etc.) found on top of the soil

litter - garbage disposed of incorrectly

loam - a soil texture which consists of equal acting parts of sand, silt, and clay; generally comprised of about 40% sand, 40% silt, and 20% clay


magma - naturally occurring molten rock

metamorphic - describes any rock derived from pre-existing rocks in response to large changes in temperature, pressure, or other environmental factors

mineral - a naturally occurring inorganic (non-living) substance having an orderly internal structure and characteristic chemical composition and other physical properties

mottles - spots or blotches of colors different from the main subsoil color


nonpoint source pollution - pollution emanating from disparate, hard to identify sources




old growth forests - forests containing trees that are often hundreds, sometimes thousands, of years old; examples include forests of Douglas fir, western hemlock, giant sequoia, and coast redwoods in the western U.S.

organic matter - dead and decaying plants, animals


parent material - the layer of very little weathering from which other soil layers develop

ped - the smallest unit of soil

permeability - the rate at which water moves down through the subsoil

photosynthesis - the process by which chlorophyll-containing tissues of plants use light and carbon dioxide from the atmosphere to produce glucose and oxygen; the process by which plants clean the air by taking in pollutants and gases through their leaves and roots and convert them to harmless substances

plateau - an elevated area of relatively flat land. It is often limited on at least one side by an escarpment, or an abrupt drop to lower ground

plutonic - describes igneous rocks formed deep beneath the earth's surface

point source pollution - pollution emanating from and traceable to a distinct point of origin

pollution - the addition of unwanted substance to or the alteration of the environment in a way that adversely affects human health or living systems. Pollutants may be biodegradable, non-biodegradable, or slowly degradable.

pollution prevention - the reduction or elimination of pollutants prior to removing off-site for recycling, treatment, or disposal. P2 (as it is called) can include substitution of different raw materials, reduction of toxic chemical use, and increased recycling or treatment of wastes. Companies often find reduced costs for raw materials, energy, pollution control, and waste disposal, while fewer pollutants are discharged into the air, water, or land. Preventing pollution improves the environment today and may help prevent tomorrow's problems.

pulp - fibrous material prepared from wood, recovered paper, cotton, and grasses by chemical or mechanical processes; used in making paper or cellulose products

pulpwood - timber that is cut and made into pulp for paper and other products


Quinine - a drug used to cure and prevent malaria that comes from Peruvian bark


reforestation - the renewal of forest cover by natural regeneration or the planting of seeds or seedlings

resin - a substance from trees used to make varnish, lacquers, inks, and plastics

riparian buffer - a zone of vegetation along a river or stream corridor that offers wildlife habitat and helps absorb runoff from the land during storm events

runoff - water lost by surface flow


saltwater intrusion - occurs when groundwater supplies are depleted to the extent that coastal waters infiltrate local aquifers

sapwood - the younger, softer, living, or physiologically active outer portion of a tree's wood that lies between the cambium and the heartwood and is more permeable, less durable, and usually lighter in color than the heartwood. The tree's water and nutrient needs are transported within the sapwood.

sedimentary - describes a layered rock resulting from the consolidation (cementing) of sediment

seedling - a young tree grown from a seed up to a small sapling

selective cutting - the cutting of intermediate-aged, mature, or diseased trees in an uneven-aged forest stand, either singly or in small groups. This encourages the growth of younger trees and maintains an uneven-aged stand.

shelterwood cutting - the removal of the understory of a forest so that younger saplings can grow in the shade of older and larger trees

sick building syndrome - term used to describe the effects of high levels of indoor air pollution

side effects - term used to describe conditions resulting from (or reactions to) exposure to health hazards, toxins, chemicals, and drugs

silt - soil deposits caused by water run-off; one of the three particle sizes found in soil, between sand and clay in size

silviculture - management and cultivation of forests

skidder - a large machine that drags harvested wood from the forest floor to a loading area

slope gradient - the rise or fall of the land

soil profile - a cross-section cutting down through the different soil layers or horizons

soil structure - the manner in which individual soil particles are grouped together

soil texture - the relative proportion of sand, silt, and clay found in a soil; the feel of the soil

subsoil - a soil layer under the topsoil and above the bedrock

succession - used here to describe forest communities; the natural evolution (or cycle) of birth, growth, maturity, and death

sustainable use - managing resources so that they produce continuously, unimpaired by periodic harvests


tannin - chemical used to tan leather; found in many trees

terracing - making a long pile of earth with sloping sides and a flat top; usually done along rivers to control flood waters

timber cruise - a survey of a forest or forest stand to mark trees to be harvested

topography - the general description of a land surface including its relief and the position of natural and man-made features

topsoil - the upper layer, "A" horizon of soil in which plants grow; usually richer in plant food than the subsoil; the plowed layer


water pollution - sewage, industrial chemicals, heavy metals, and household cleaners are examples of materials commonly discharged into streams and rivers. In addition, chemicals from the air dissolved in rainwater, pesticides, and fertilizers leached from the land run off into water

watershed - land area that collects and channels water to a common outlet. Each lake, river, and stream collects its water from the surrounding watershed.

weathering - all physical and chemical changes produced in rocks and soils by the forces of climate

windbreak - a row of trees which serve as protection from the wind


xylem - the complex woody tissue of higher plants that includes systems for transporting water storing nutrients, and structural support