Glossary

abdomen — The abdomen of an insect is in the hind section. It holds the sexual, digestive, and excretory organs. It also holds the breathing mechanism.

abiotic — Non-living material such as water, rocks, and minerals.

adapt — Fitting by alteration or adjustment.

adapted — Alteration in the structure or function of an organism in any of its parts, by which the organism becomes better fitted to survive in its environment.

alkaline — An alkaline substance is comprised of salts and other dissolved materials and is often found in desert soils and water; alkali can neutralize acids. Alkaline water is bitter, slippery, and caustic.

alluvial — Referring to landscape features produced by deposits of mud, clay, silt, gravel, or sand; made by a stream.

alpine zone — The portion of land that lies above treeline. Extreme weather conditions make survival impossible for tall trees. If trees do exist, they grow no higher than a few feet high and tend to sprawl across the ground. Scientists call these trees "krummholz." Alpine plants usually have adaptations for minimizing the effects of wind, cold temperatures, short growing seasons, dry conditions, and ultraviolet radiation.

altitude — Vertical elevation of an object above sea level.

amphibian — An animal without scales, adapted for life both in water and on land. Examples are frogs, newts, and salamanders.

angle of repose — The maximum slope or angle at which a material --such as sand-- will remain stable, without sliding or rolling.

antennae — The long, thin, jointed projections from an insect's head that inform it about the feel, sound, taste, smell, temperature, and humidity in the world outside of its skeleton.

anthropologist — A person who studies the culture and lifeways of peoples from the past and of today.

antidunes — Sand ripples in the stream that appear to travel upstream. They act like dams and hold the water back until the water pressure breaks them, sending a pulse of water downstream.

anther — The part of a flower's stamen that contains pollen.

antlers — Bony growths from the head of members of the deer family, such as mule deer and elk. They are shed and regrown every year, requiring large amounts of calcium.

aquifer — Water-bearing rock formation or group of rock formations.

archaeologist — A person who studies that which remains from a past human culture: art, tools, games, skeletons, buildings, trash, anything left behind.

arid — Lacking moisture especially because of insufficient rainfall; dry.

arrastre — Spanish grinding device to extract gold or other ores.

artifact — An object produced by human workmanship, especially a tool, weapon, or ornament of archeological or historic interest.

atlatl — Throwing stick with a handle on one end and a pit or cup in the other, used in combination with a spear. When the spear was thrown, the atlatl remained in the hand thus extending the throwing arm.

banding — To identify birds and other small to medium sized animals, park researchers attach plastic or metal bands to the animal's leg. Animals are recognized by the color, pattern, and/or number on the band. Banding helps researchers determine a species population and their home range.

basalt — A hard, dense, dark volcanic rock.

baseline — Scientists study nature and try to determine the way an ecosystem or a species functions in its natural state. The baseline heart rate of a human is approximately 72 beats per minute.

behavior — All organisms interact with their environment and with other organisms. These actions and responses are types of behavior.

benthic macroinvertebrates — Bottom-dwelling aquatic animals without backbones (invertebrates) that are visible with the naked eye (macro).

bio-indicator — Researchers monitor certain species populations to determine the health of the environment. A species may serve as a good bio-indicator if it depends on stable conditions. If environmental conditions change ever so slightly, these species' populations may change dramatically. Watching these populations helps scientists forecast broader environmental problems such as climate change, ozone layer destruction, biodiversity loss, and global air/water pollution.

biodegradable — The property of a substance allowing it to be broken down by microorganisms into simpler components (atoms, molecules, or compounds). The simpler components are later used by other organisms.

biogeography — The study of how organisms interact with the physical landscape.

biological diversity — The variety and variability of living organisms on the planet.

biological integrity — Ecological systems, such as forests, deserts, and oceans, are sometimes wea (low integrity) and other times strong (high integrity).

biologist — Park biologists study plants, animals, and their ecosystems from the smallest microbes to the largest forest. Studying life helps us learn how systems work, understand our roles, and know how to limit our impact on ecosystems.

biology — The study of life.

biotic — Pertains to living organisms.

bimodal — Referring to two main directions or influences.

blowout dunes — A general term for various saucer, cup, or trough-shaped hollows formed by erosion on a pre-existing dune or other sand deposit. Vegetation is often found on blowouts.

bore — A wall of water or wave, usually produced by tidal action. In Medano Creek, bores are formed by the surge flow of the creek.

botany — The study of plants.

braided stream — A stream that repeatedly divides and recombines, forming many small wandering channels.

browse — To eat twigs and leaves of woody plants. Examples of browsers are deer, elk, and moose. Browsers may eat grass and other softer growth when it's available, turning to leaves and twigs in winter.

buffer — Buffers are sponges in nature. Natural buffers hold water to prevent flooding, detoxify poisonous chemistry from the air and water, retain biological integrity during times of ecological stress, etc.

burrow — A hole or excavation in the ground made by an animal for shelter or habitation.

cambium — Layer of delicate tissue between the inner bark (phloem) and the wood (xylem), that produces all secondary growth in plants and is responsible for the annual rings of wood.

camouflage — Many animals are disguised or hidden by their coloration, texture, and morphology. Some predators are camouflaged to help them sneak up on prey. Other animals use cammouflage to hide from predators.

canopy — The layer formed by leaves and branches of a forest's trees.

capillary action — Through the adhesive forces (sticky property) of water, water is able to move through tiny spaces. With the help of capillary action, water can seemingly defy gravity and move upwards through a tree to its topmost branches.

cardinal directions — The four primary points of the compass: north, east, south, and west.

carnivore — An animal that feeds principally on the meat of other animals.

carrion — The flesh of an animal that is already dead. Carrion provides food for many scavengers, from insects to black bears.

carrying capacity — The maximum population of a given animal (or of humans) that an ecosystem can support without being degraded or destroyed in the long run. Carrying capacity may be exceeded, but not without lessening the system's ability to support life in the long run.

cavity — A hole in a tree that can be used by animals for shelter.

channel — Bed where a natural stream of water flows.

chlorophyll — The green pigment used by plants to capture the sun's energy in order to perform photosynthesis.

chromosomes — A string-like part in the nucleus (brain) of a cell that stores the directions for the cell.

classification — In order to have knowledge of nature, we must classify nature into subdivided groups. There are two schools of thought in the process of scientific classification: the 'lumpers' and the 'splitters'. Which are you?

climate — The average pattern of weather variation at a certain location, over a long period of time.

Clovis culture — A population of people in existence approximately 11,000 to 12,000 years ago.

Clovis point — Stone spearheads used by early Native Americans. These points are approximately four inches long, with a groove or flute along the face. They were first discovered in Clovis, New Mexico.

coevolution — The process by which two or more organisms develop specialized traits and characteristics in accordance with the other. Species which have coevolved with each other usually depend on each other for survival.

commensalism — One organism benefits while the other is neither harmed nor benefited. Example: moss growing on trees benefits by being raised above forest floor competition, while the tree doesn't get much out of the deal either way.

community — All the plants and/or animals living together in a particular habitat are connected by food chains, food webs, and other relationships. Groups of species live in communities.

competition — Organisms have a wide variety of strategies that help them gather resources. They may compete with each other for resources such as water, food, shelter, space, and mates. Through competition, species are strengthened in their ability to cope with difficulties.

composite — Flowers within the Asteraceae family are grouped together as composites. The flower heads are typically comprised of many smaller flowers.

condensation — The process by which a substance changes from a vapor or gaseous state to a liquid form. a common example is water vapor in the air condensing into droplets of liquid on the outside of a cold drinking glass. The condensation of water vapor into clouds and precipitation is a vital link in the water cycle.

cone — A pine cone, a fir cone, a spruce cone, etc. Cones are the structures in which the pollen (male cone) or seeds (female cone) of a tree are contained. They are also important food items for many forest birds and mammals.

confined aquifer — A layer of water beneath the surface of the earth that is trapped below an impermeable upper layer. The confining layer is usually composed of clay.

conifer — A cone-bearing tree which has needle-leaves or scales, and which is usually evergreen. Pine trees, fir trees, etc. are conifers.

conifers — A predominately evergreen, cone-bearing tree, such as a pine, spruce, hemlock or fir.

conservation — The intelligent use of natural resources; a philosophy of natural resource management that ensures their availability in the future by not being too greedy in the present. Conservation practices, by preserving land for future use by humans (the technical definition of conservation), has the secondary benefit of providing habitat and thus survival for many plants and animals not commonly thought of as resources, such as wildflowers and songbirds. Another definition is preserving resources from decay or loss.

consumer — A person or other animal who uses things: a rabbit is a consumer of grass; a fox is a consumer of rabbits; a person is a consumer of potato chips, televisions, and automobiles. In nature, there a two kinds of consumers, primary and secondary. The rabbit above, as a consumer of plants, is a primary consumer. The fox is a secondary consumer. (Since the rabbit is essentially made out of rearranged grass, the fox, by eating the rabbit, is consuming the plants secondarily, and so is a secondary consumer.)

crepuscular — An animal that is most active during the hours of dawn and dusk. Deer are a good example.

crown — The upper branches and foliage of an individual tree.

cycle — A continuous process; a circular flow of energy or nutrients.

data outlier — Data that does not fit the overall trend.

deciduous — A plant (usually a tree) that loses its leaves during an unfavorable time of year. In North America, most broad-leafed trees are deciduous and lose their leaves in the autumn. In the tropical rainforests, however, deciduous trees drop their leaves during the dry season.

decomposers — The community of fungi, bacteria, insects, and other scavengers that consume and break down dead plant and animal material into simpler component atoms, molecules, and compounds, thereby making the materials available to be used again. If you dismantled a house to use the lumber again to build another house or other project, the ones who did the dismantling could be considered the decomposers.

decomposition — The process of breaking dead plant and animal material into simpler components (atoms, molecules, and compounds) so the materials can be used again. You can think of it like taking a Lego set apart into its component bricks. A dead tree turns into a log, which then slowly turns (decays) back into the soil, out of which new plants can grow, as a result of the process of decomposition.

density — Density describes the amount of space filled by an object. In ecology, if trees are widely spaced upon the landscape, tree density is low. If the number of bark beetles per acre is above normal, bark beetle density is high. In chemistry and geology, density usually describes the amount of mass per volume.

dichotomous key — Botanists and other biological scientists use dichotomous keys to identify species. These keys use characteristic-based 'yes' or 'no' questions to identify species, beginning with generic traits and becoming more specifc.

dicot — Referring to plants whose seedlings have two seed leaves, for example a bean.

disk flower — Some composite flowers have ray flowers along the margins and disk flowers in their centers. Disk flowers usually have petals which are reduced in size or tubular in shape.

dispersal — In plants, the method in which seeds are distributed. Wind, water, and animal transport are three common methods of seed dispersal.

dissolved oxygen — Aquatic life depends on oxygen to breathe, as does all life. But for oxygen to be available in water, it must be dissolved first. Oxygen dissolves in water when tiny air bubbles are trapped by churning river rapids or waterfalls, and as a byproduct of aquatic plant photosynthesis. Rivers that have excess amounts of nutrients can become low in dissolved oxygen, due to overuse by microorganisms.

diurnal — Describes an animal that is most active during hours of daylight. Humans and most birds are good examples.

diversity — A single unit made up of many different individuals. A neighborhood having people of many different nationalities and races living in it is diverse. A natural community having many different kinds of plants and animals living in it is also diverse. In nature, diversity is important not only aesthetically, but also in terms of survival. A community weak in diversity (i.e. having few or only one kind of organism in it) can be devastated if something affects that population. Many modern farms, for example, are vulnerable to attack by insects and disease because of their huge areas of single types of plants. Diversity allows some species to flourish even if others are negatively affected. Although diversity is important, healthy ecosystems must have a balance between high diversity and low diversity. If an ecosystem is too diverse, vital ecosystem processes can lose their functionality.

domestication — The process by which wild animals are tamed for human use. Animals such as dogs, pigs, cows, and sheep were domesticated from their wild relatives by humans thousands of years ago.

dominant species — The most abundant, prevalent, or influential species in a given area.

drainage — A natural system of drains that channel surface water.

ecological role — Carpenters, bakers, grocers, doctors, and waste recyclers all have very important roles within your community. It would be very difficult for your community to survive without many of these roles. Could you do without a mechanic? How about a farmer? Organisms within ecosystems have roles too. Look in any ecosystem and you will find farmers (plants), landscapers (grazers), lawyers (predators), teachers (processes) home builders (trees), water treaters (wetlands), food transporters (fish), waste recyclers (bacteria), and many more. What is your role within the ecosystem?

ecology — The study of the relationships of living organisms to their environment.

ecosystem — A dynamic interacting system made up of living organisms and all the components of their nonliving environment. Ecosystems are linked together by processes such as energy and nutrient flow.

ectothermic — Cold-blooded.

efficiency — Producing growth with little waste. Intact ecosystems are highly efficient. Young ecosystems are much more wasteful with their use of energy.

endemic — A species that is unique to an area; found nowhere else.

endoskeleton — An internal skeletal structure, consisting of cartilage and bones, found in vertebrates.

environment — All the living and nonliving things, such as plants, animals, soil, weather, etc., that affect the existence of anything in that community.

eolian deposit — Wind-deposited material or sediment.

eolian — Geologic features formed by the wind. Sand dunes are examples of an eolian stucture.

erode — To wear away at something, as water erodes a rock.

erosion — The removal of soil and/or rock by wind or water. Although a natural process, it can nonetheless be very damaging if it occurs too rapidly.

evaporation — The process of a substance changing from a liquid form into a vapor. If a bowl of water is left out, it will eventually seem to disappear as the visible liquid changes into invisible water vapor. The evaporation of water is a vital link in the water cycle.

exoskeleton — The external skeletal support found on the outside of an insect or other invertebrate.

exotic — Foreign species or matter that did not originate in a landscape. In botany, exotic plants are those that have been carried to an area (usually by humans) from a distant location. In geology, exotic rocks are those that are not of the local bedrock and have arrived to a terrain by a force such as ice sheet movement.

extinct — Something that is no longer in existence.

farm — A piece of land used to produce plants or animals for human use.

fault — A break in the continuity of a rock formation, caused by a shifting or dislodging of the Earth's crust.

fauna — A list of the animals living in a particular ecosystem.

fecundity — The number of and viability of a species' offspring.

feedback — To maintain efficiency and stability, all natural systems recycle their waste products. Healthy ecosystems re-feed their wastes back into the system.

flavinoids — A group of aromatic compounds found in plants, usually as pigments, such anthocyanin.

flora — A list of the plants living in a particular ecosystem.

flow — In hydrology, the quantity of water moving through a river or stream during a period of time. Traditionally, water is calculated in cubic feet per second (CFS).

Folsom Culture — A population of people in existence during the late Paleo-Indian period.

Folsom point — These points are smaller and were created more recently than Clovis Points. They have a long groove or flute running up each side and were first discovered in Folsom, New Mexico.

food chain — A series of plants and animals linked together by their food relationships. An example of a three-part food chain is: grass eaten by a rabbit, which is eaten by a fox. In nature, food chains rarely exceed four or five links.

food web — The complex arrangement of who-eats-who in an ecosystem. Food chains are linked together to form food webs.

forest floor — The layer of decomposing material that covers the soil in a forest.

forest — A diverse community of plants and animals in which trees are the most conspicuous members.

fungus — A group of plants that includes mushrooms and molds. These organisms decompose organic material, returning nutrients to the soil.

genetics — The study of genes and their passage through generations and adaptations.

genus — A classifcation category within the scientific taxonomy of organisms. The genus category is more specific than family and more general than species.

geology — The science and study of the Earth, its composition, structure, physical properties, history, and the variety of processes that shape or affect it.

glaciation — The alteration of a land surface by a massive movement of ice.

granite — A coarse-grained igneous rock consisting mostly of the minerals quartz and feldspar.

gymnosperm — ("naked seeds") A type of vascular plant which is more primitive than the flowering plants (angiosperms). Gymnosperms commonly have seeds within a cone.

habitat — Where an organism lives in an ecosystem and finds all it needs to survive; the native environment of an animal or plant.

hearth — A location or remains of a location where a fire was built.

herbivore — An animal that eats only plants.

hunter-gatherer — A nomadic method of subsistence whereby animals are hunted and plants are gathered for food.

hydrology — Hydrology is the study of water and the way it courses through landscapes, geology, and living things.

igneous — One of the three main rock types. Igneous rocks are formed when molten rock solidifies.

indicator species — See bio-indicator.

insect — A six-legged arthropod usually with a hard exoskeleton. Many are capable of flight. Examples are beetles, flies, grasshoppers, etc.

insecticide — A chemical compound used to kill unwanted insects.

insectivorous — An animal or plant that feeds primarily on insects is considered insectivorous. Some bats are insectivorous mammals.

instar — Many larval insects go through successive molts (or instar stages) before they can mature into an adult. For example, the Great Sand Dunes Tiger Beetle molts three times before becoming a teneral adult.

interdependence — In all environments, various plants and animals depend on each other either directly or indirectly for survival.

interdunal pond — In eolian environments such as sand dunes, interdunal ponds (which are found among the dunes) are extremely important to life in these dry sandy environments. Animals seek water and food in these locations.

interpretation — In natural and cultural history education, a term that defines the role of the teacher as one who interprets the stories that are inherent in a place, person, or idea.

invasive — n. An exotic species that has few natural enemies and that can quickly multiply upon the landscape. v. To crowd out other species and quickly multiply upon the landscape.

inventory — Scientists create knowledge-bases of species and components of a landscape in order to understand how nature is composed. By knowing what is in a landscape, scientists will know what there is to protect.

invertebrate — An organism with an exoskeleton (such as insects, spiders, and crabs) instead of a backbone.

labium — The lower lip of an insect.

labrum — The upper lip of an insect.

latitude — Angular distance North and South of the equator, measured in degrees.

lichen — A plant that is a combination of a fungus and an alga; commonly grows on trees or rocks.

life zone — A life zone is an area on the landscape which is characterized by a like climate and a dominant set of species. On mountain ranges, life zones transition vertically. For example, tundra is the highest life zone, where no trees can survive the extreme temperatures, fierce winds, and short growing season.

magnetite — A black mineral composed of iron oxide which is attracted to magnets.

mammal — A group of air breathing animals having four appendages, fur or hair, and mammary glands. All but a very few are placental.

mandibles — The main grinding mouth-part of an insect.

mano — A hand-sized, rounded stone used to grind grains and seeds into flour. Manos are used with metates.

maxillae — The second pair of jaws in an insect's mouth, used for pushing food down the throat.

mean — Approximating the statistical norm or average

metamorphic rock — One of the three main rock types. Metamorphic rocks have been changed by great heat or pressure.

metate — The larger, lower grinding stone used to grind grains into flour. Metates are used with manos.

meteorology — The science and study of the weather and of atmospheric processes.

midden — A pile of refuse. Archaeologists study middens left behind by ancient cultures to learn more about their habits and lifeways.

migration — Many animals move to a different location to find a better place to endure seasonal changes, find food supplies, breed, nurse young, find adequate space, etc. Migrations may be repeated within a species from year-to-year and even from generation-to-generation.

mineral — An inorganic material, usually refers to homogeneous crystalline compounds.

monocot — A plant whose seedling has only one seed leaf. A grass is an example of this group. Those having conspicuous flowers have their flower parts in threes.

monoculture — The growth or cultivation of only one species in a given area.

mordant — From Latin "to bite," mordants are chemicals used to fix pigments into fabric during the dyeing process.

morphology — The physical structure of an organism. The visible characteristics of a species.

multimodal — Relating to or characterized by several different directions or influences.

mutation — A change in a hereditary characteristic that produces a new trait which can be inherited.

mutualism — A relationship in which both organisms benefit from the arrangement. Example: bees and apple trees have a mutually beneficial relationship in which the bees get pollen and nectar, while the trees get pollinated.

mycelium — The mat of very thin filaments that comprise a fungus.

native — Any species which is found in the region of its origin; any species that has not been newly introduced by humans into an ecosystem.

needle — The narrow leaves of most coniferous trees are described as needles.

niche — The role a particular species plays within its ecosystem; this includes its selection of food, water and shelter sources as well as other facets of its behavior.

nitrogen fixation — All plants need nitrogen to survive. Despite the fact that over 75% of our atmosphere is composed of nitrogen, it is in an elemental form that plants cannot use. Only certain kinds of bacteria associated with certain plants can "fix" the nitrogen into a usable form, which involves breaking the original molecule and adding hydrogen. These bacteria do this for themselves of course, but a lot of the nitrogen leaks out into the surrounding environment in different ways, where it is quickly snatched up by plants. Growth in many forest systems is limited by nitrogen levels. Manure is high in fixed nitrogen, and thus, is useful as fertilizer.

nocturnal — Animals that are most active during the hours of darkness are nocturnal. Bats, mice, and moths are good examples.

nomadic — Refers to tribes or people who wander. Often these groups of people followed their food sources. They moved in response both to the seasonal maturation of edible plants and also to the seasonal migrations of animals.

nonnative — A species of plant or animal which did not originate in its present location. The Norway rat is nonnative to America.

nutrient — Any organic molecule needed by a plant or animal can be called a nutrient.

obsidian — Rock composed of black or banded volcanic glass, displaying curved, lustrous surfaces when fractured. It was often used to make sharp tools.

omnivores — Animals that eat many different kinds of foods, including plants, insects, and other animals.

opportunist — An animal or other organism that takes advantage of the most abundant or easily obtainable source of food.

ore — A metal, such as gold, in its raw state when it is extracted from the ground.

ornithologist — One who studies birds.

parabolic dune — A dune in the shape of a parabola, with a concave windward slope and a convex leeward slope. The trailing ends of parabolic dunes are anchored by vegetation.

parasitism — A relationship in which one benefits, while the other is harmed. Example: a flea is a parasite on a dog. The flea benefits by drinking the dog's blood, but the dog, by losing blood and acquiring discomfort adn potential disease, is harmed.

pellet — Owls eat their prey whole and after the meal is digested, they regurgitate undigested bones and hair in the form of a pellet.

phloem — Small tubes that carry food from where it is photosynthesized in the leaves to the roots and other places in a plant where it is used and stored.

photosynthesis — The conversion of light energy into chemical energy (sugars). This process takes place in green plants, as they create their own food using water, air, and sunlight.

pigment — A wide variety of organic compounds found in plants and animals which have color (or are colorless in some cases) and perform various functions. Chlorophyll is one pigment found in plants, which aids in the manufacture of food.

pioneer — A plant adapted to rapid colonization of ground recently vacated by its previous inhabitants. Pioneer plants usually grow very quickly and can often prosper in poor soil. Most of the plants in a vacant lot are going to be pioneer species, as are the plants trying to make a go of it in your gravel driveway, on a logged hillside, or after a forest fire has burned through an area.

plant — A photosynthetic organism, usually multicellular.

playa — In arid basins, where rivers merge but do not drain, playas sometimes form. Playas are flat areas that contain seasonal or year-to-year lakes that often evaporate, leaving minerals behind.

Pleistocene — An epoch in earth history from 2-5 million to 10,000 years ago. A series of glacial and interglacial periods affected the climate and vegetation of the epoch.

pollination — The movement of pollen in a plant from the stamen (male structure) to a plant's ovary (female structure).

Precambrian — The oldest and largest division of geologic time; includes all time from the origins of the earth to about 600 million years ago.

precipitation — When water falls from the sky in the form of rain, snow, etc.

predator — An animal that depends on or preys on other animals for food.

predictive models — Oceanographers, physicists, ecologists, and other scientists input data and variables from nature into models and computer programs to try to predict the future of an ecosystem or natural process. Meteorologists do this daily in their weather forecasts. These predictive models tend to lose accuracy in time.

prehistoric — Occurring before written human history in a given area.

prescribed burn — When the health of a forest or grassland depends on fire and it is not possible to allow the landscape to burn naturally (sometimes due to homes or buildings nearby) forest ecologists carefully manage an intentionally-lit fire.

preservation — To keep from injury; maintain and protect.

prey — An animal that is eaten by other animals.

proboscis — The long drinking tube used by insects like the butterfly.

processes — The 'action verbs' of an ecosystem. For example: consume, decompose, exchange, produce, transfer, recycle, reproduce, and succeed are all ecosystem processes. These processes unite biological communities together into a web of life. The process that binds human community together is communication.

producer — In nature, 'producers' generally refer to organisms near the bottom of the food chain, namely plants. They are producing organic material from inorganic components like carbon dioxide and water.

productivity — Land managers use the term productivity to describe the quantity of a resource or the amount of energy produced by an ecosystem. Land productivity is naturally higher in early succession ecosystems and lower in climax (undisturbed, old) ecosystems.

Pueblos — Refers to the group of Native Americans that began living in the Rio Grande Valley some 1,000 years ago. It is also the term for the communal village in which they lived.

radio-carbon dating — A method of absolute dating that was developed by William Libbey. The method is based on the fact that all living organisms absorb carbon from the atmosphere and once the organism dies, the carbon begins to decay. Scientists can measure how many years have elapsed since the organism lived. It is most accurate for dating wood, charcoal, and bone up to 50,000 years old.

rain — Liquid precipitation.

range — The entire area where a certain species exists.

ray flower — Some composite flowers have ray flowers along their edges and disk flowers within the center. Ray flowers usually have a petal which radiates outward from the composite flower's center, such as the petals on a sunflower.

reach — A portion of a stream or creek that is mapped and monitored by researchers.

recharge — The addition of water to an aquifer by natural infiltration; the replenishment of ground water in a saturated zone by seepage of precipitation and runoff.

recycle — A very sensible practice of using things over again instead of throwing them away.

reptile — An ectothermic (cold-blooded), air-breathing animal with scales and a backbone; includes snakes, lizards, turtles, etc.

resource — A source or supply of something.

respiration — The metabolic process by which plants and animals convert food to energy. In humans, as with other organisms, breathing out carbon dioxide is a product of respiration.

rhizomes — A root-like, usually horizontal stem growing under or along the ground that sends out roots from its lower surface and leaves or shoots from its upper surface.

riparian — Refers to the life or ecosystem around a stream, river, creek, or sometimes a lake.

rodent — A very successful group of mammals that have enlarged incisor teeth; includes rats, mice, squirrels, beavers, etc.

roost — Bats, owls, and other flying creatures take rest in roosts. Owls roost by perching upright in tree cavities and on branches. Bats hang from trees, cave walls, tree bark, attics, and other safe hollows when roosting.

sabkha — Sabkha is an Arabic name for a salt-flat ordinarily found near sand dunes. These relatively flat and very saline areas of sand or silt form just above the water-table, where the sand is cemented together by evaporite salts from seasonal ponds.

saltation — The bouncing or 'leaping' movement of sand grains caused by the wind.

sample — A portion of a whole that is chosen to represent the whole in an experiment.

sand — Loose, granular, gritty particles, resulting from eroded rock. Sand particles are finer than gravel and coarser than dust.

sapwood — The complex vascular system within a tree through which water and minerals are transported and distributed.

scat — The excrement of an animal.

scavenger — Scavengers are opportunists who search for or take advantage of useful dead organic material; usually described as a member of the decomposer community, but not all scavengers always consume carrion. A coyote, for example, will kill a rabbit, but will also take advantage of a dead deer it may happen across. It doesn't behave as a scavenger when hunting the rabbit, but it does when feeding on the dead deer.

sediments — Loose material deposited by wind, water, or glaciers.

sedimentary rock — One of the three main rock types. Sedimentary rocks were formed by the accumulation of layers of silt, sand, mud, stones, etc. on the bottom of a body of water or on the land by wind. Geologists can tell a lot about what happened in the past by examining these layers, how they are distributed, what is in them, etc.

seed — The reproductive part of the plant. May (as in apples) or may not (as in grasses) be inside a fruit. Seeds sometimes habe wings, barbs, or other means of dispersal.

shade-tolerant — Vegetation, especially trees, that have the ability to grow in low-light conditions are considered shade-tolerant. Many late-succession tree species fare well due to their love of shade and can become the dominant species in a forest ecosystem.

silt — Rock material composed of fine mineral particles intermediate in size between sand and clay.

snags — Standing dead trees.

species — A group of organisms different from all others in that they do not interbreed with any other groups.

specific heat — The amount of heat it takes for a substance or material to be raised one degree C; a measurement of a material's capacity to store thermal heat.

spore — The reproductive 'seed' from fungi such as mushrooms and lower plants such as ferns and mosses. Some spores are indigestible, so are often distributed by traveling for awhile in the gut of the animal that ate the mushroom. Many spores are small enough to waft away on the wind, sometimes traveling hundreds or even thousands of miles in the upper atmosphere.

stability — Ecosystems tend toward stability. If not, trees would grow at angles to the earth, deer populations would spread like wildfire across the globe, and mountains unimpeded by erosion or gravity would thrust into space.

stomata — Stomata are small holes on the underside of a leaf through which water is transpired. On needle-bearing trees such as spruce, pine, and fir, large rows of stomata can be seen as the white stripes on the underside and/or top of each needle.

stylets — Sharp appendages on an insect, used for piercing and sucking.

subalpine zone — The area between the continuously forested montane zone and the high elevation alpine zone. Usually very park-like in appearance, characterized by a mixture of alpine and forest shrubs and herbs interspersed with patches of trees.

succession — All ecosystems and plant communities go through what scientists call succession. In the early stages of succession, bare ground is colonized by pioneer species. Pioneer species can quickly populate areas which are low in nutrients and high in sunlight. As the ecosystem matures, successive stages of plant and animal species inhabit the landscape. Mature ecosystems, such as old-growth forests, are often low in biological diversity, but high in process integrity.

suppression — Where wildland fires have been stopped by human methods, fire ecologists consider natural fires to have been suppressed in that landscape. Fire suppression can sometimes lead to an extremely hazardous situation, as downed and dead wood accumulates and increases the possibility of a disastrous, unnaturally hot fire.

surface tension — The attractive forces between water molecules creates what is called surface tension. Surface tension creates a strong boundary between the air and water, which allows some insects to walk on water and keeps water from evaporating too quickly.

surge — To rise high or move as if in waves.

survey — Researchers survey an area to record an organized, detailed set of information on the nature of what they are exploring.

symbiosis — A relationship in which plants and/or animals live together in some interconnected manner. There are different ways symbiosis can happen: parasitism, commensalism, and mutualism. Most organisms function under a varied combination of all three symbiotic methods during different phases of their life cycle.

systematic — Science in general is a systematic approach to discovery. Systematic sciences follow logical, consistent, and ordered methods.

talus — Where mountains have crumbled and vegetation has not yet taken hold, slopes of talus (large rocks) and scree (small, loose rocks) remain.

taxon — Similar to the word "species," but used to describe a more general, less specific group of organisms; plural, taxa. Taxonomy refers to a system of classification.

teneral adult — The stage of maturity after the last molt, when an insect has taken the adult form, but has not matured enough to be able to reproduce.

territory — An area within the range of an individual animal that it will defend against intruders. For example, a fox might range over an area of several square miles, but only defend a small area near its den, and then only when it has young. You might range over an entire city and beyond, but only defend your own property or maybe only the house. You too will become much less tolerant of intruders (i.e. defend a larger territory) if you have children around.

thorax — The thorax is the middle section of an insect. It is where an insect's six legs and wings attach to the body.

trait — A distinguishing characteristic of an organism that makes it what it is.

transect — A narrow strip along which researchers count organisms within communities to determine species populations and variability.

transpiration — Transpiration is the loss of water vapor from a plant through small holes (stomata) in leaves or needles. This process allows the plant to release water that has been absorbed by the roots and transported through the rest of the plant. Transpiration is one way water is cycled back into the atmosphere.

treeline — The elevation where the trees end and subalptine or alpine meadows begin. The elevation of treeline varies with latitude and climate.

trophic levels — Referring to the hierarchy within the food chain. Because energy is lost in the form of heat at each level within the food chain and the quantity of life that can be supported becomes smaller at each level, trophic levels are usually visualized as a pyramid. All biological systems are typically composed of four trophic levels: producers, herbivores, small carnivores, and large carnivores.

trough — In the dunes, long narrow depressions between ridges of sand.

unconfined aquifer — An aquifer with no confining, impermeable geologic structure above the saturated layer (the water table forms the upper boundary of the aquifer); an aquifer containing water that is not under pressure.

undescribed — A species of animal is discovered but there is no published scientific description of a species yet.

unimodal — Referring to one main direction or influence.

variability — The proportion or ratio of organisms within a community. Instead of counting each and every organism, scientists measure the variability of populations to look for change over time. In your class, student variability may be four girls for every three boys.

variable — In the scientific method, variables are the different parts or characteristics in nature. In the science of fire ecology, for instance, fuel, vegetation type, brush, tree size, density, species, and climate are all variables that affect how fire plays out its role in a given landscape.

vascular — Vascular plants contain tubing that pumps sugars, nutrients, and water through their tissues. Non-vascular plants, like mosses and liverworts, have poorly developed fluid transportation systems.

velocity — Speed or rate of movement.

vocalization — A term used to describe sounds made by birds and other animals. As with humans, vocalizations are produced to communicate within and among species.

water cycle — The process by which water keeps getting used over and over again. Very basically, water cycles from the ocean up into the sky. The clouds then travel over land, where they drop their load of water, which flows back to the sea.

watershed — A topographical basin or drainage that funnels water into one major river, lake, water body, or other location.

waypoint — A specific location, often designated by a set of coordinates and stored in a GIS (Geographic Information System) database.

wilderness — Wilderness areas are natural areas that are managed to maintain their primeval character and influence, without permanent improvements or human habitation. The National Wilderness Preservation System protects legislated Wilderness areas managed by a variety of federal agencies, including the National Park Service.

wildlife — Usually refers to large wild animals like deer, mice, birds, etc. that have not been domesticated for human use. The term is generally not used to describe smaller animals like insects.

wind regime — The pattern of winds in a given location, sometimes illustrated by a wind rose diagram.

Glossary modified and expanded from original text supplied by teachers Tom Butler and Lori Cooper.