Anaerobic decay     The breakdown of energy-containing substances by the activity of  bacteria and other microorganisms in the absence of oxygen.

Bacteria     Very tiny, single-celled organisms that make their living by chemically altering materials around them. They can then absorb the changed materials into their own life-supporting system. See Nitrogen-fixing bacteria.

Base line     The first or original measurement to which other following measurements can be compared to determine the amount of change or lack of change in a situation or condition.

Biologist     A scientist who specializes in the study of living things and their life functions or condition.

Biomass     The amount of living material in an organism or all organisms living in a specific area, often stated in grams per square meter.

Biosphere     The thin layer of the earth, including its atmosphere, where living things are found.

Calories     Small units of measure of heat energy. Other types of energy are often expressed in terms of calories.

Canopy     The upper layer of tree leaves in a forest.

Carnivores     Animals that eat other animals.

Carrion     Dead-animal material.

Carrying capacity     A specific number of plants or animals that can be kept alive and healthy by the resources in a given environment.

Chlorophyll     The green material, a pigment, in plants which captures light energy from the sun and makes that energy available for the plant to use to support its life.

Clear-cut     An area within a forest where all trees have been cut down.

Climax community     All the living things that are best adapted to living together and in the physical conditions of a specific environment so that they will reproduce themselves and the community will persist unchanged for many generations.

Community     All the living things of many different kinds that are living together, interacting with each other, in a specific area.

Competition     An interaction between living things that occurs when there is not enough of something present in the environment to support all of them.

Composition  The kinds and amounts of living things present at a specific place, as in the species composition of a pond.

Conservation     Man’s careful and wise use of the things in his environment that are needed to live a healthy, meaningful life.

Control     In science, that part of a study that is not altered by the researcher and so is used as a basis for comparison with some other part of the study that has had some change made.

Cutover     Land that has been clear-cut.

Data     Statements of observations gathered in a careful study and recorded, using measurements wherever possible.

Decay     The breakdown of the complex materials of once-living things to less complex materials, usually as a result of the life activities of bacteria, fungi, and other living things.

Detritivores     Animals that eat dead things and the fragments of partly decomposed things.

Detritus     Dead material, usually a fragment or fragments of partly decomposed formerly living things, such as leaf mold.

Ecology     The science that involves the study of the ways living things interact with each other and with the physical environment.

Ecosystem     The total of all living things, all the features of their physical environment, and all the interactions between them. The size of an ecosystem may be very small or very large.

Element     Any substance that cannot be separated into different substances by chemical processes.

Energetics     The study of energy – where it is located, the amount present, and how it moves within the system.

Energy      The capacity to do work. In an ecosystem energy study, the potential energy of biomass may be expressed as Calories per hectare (C/h).

Energy budget     An analysis of the amount of energy entering, contained in, and passed on by living things in an ecosystem.

Energy flow     The movement of energy along a food chain.

Entomologist     A scientist specializing in the study of insects.

Environment     Conditions that surround and/or influence an object or a living thing.

Eutrophication     Process by which water becomes overrich in nutrients, as the result of pollutants which act like fertilizer, and supports an overabundant growth of plants.

Food chain     The sequence of living things that energy will pass through before being lost from the system as heat.

Food web     Intermeshing of several food chains.

Frass     Dry pellets of undigested plant material that has passed through the digestive tract of an insect and dropped as waste.

Geologist     A scientist who specializes in the study of the physical aspects of the Earth and its history, looking especially at rocks and minerals and the physical forces that act upon them.

Geometrid     A moth of the family whose caterpillars are called inch worms.

Grubs     Generally, insect larvae or, specifically, beetle larvae.

Habitat     The elements of the surroundings of a living thing that are important to the way it lives.   

Hardwood forest     A landscape covered with broad-leaved trees such as oaks, birches, beeches, or maples.

Hectare     An area equal to about 2 ½ acres of 10,000 square meters.

Herbivores     Animals that usually eat plant material.

Herpetologist     A scientist who specializes in the study of reptiles and amphibians.

Heterocampa     A genus of moths which includes the saddled prominent, an important insect of the hardwood forests of New England.

Humus     Material in and on the upper layer of soil which includes all the formerly living matter that is in various stages of decay.

Ichthyologist     A scientist who specializes in the study of fish.

Identification key     Descriptions grouped so as to enable a person to identify an unknown specimen.

Igneous     Rocks that have formed by solidification from the molten state.

Inorganic     Composed of matter that is not and has not been an important part of the chemistry of living things. See Organic.

Input     Materials and energy that are added to a system.

Instar     A growth stage of an insect, between molts.

Intrasystem cycling     The endless movement of a substance within an ecosystem. Each living thing (organism) may pass a substance on to another organism or back to the physical environment by the processes of eating, being eaten, or through decomposition. This movement is along a food chain.

Invading species     A kind of living thing that specializes in moving into and colonizing an environment, usually when the system has been upset by some disturbance such as a fire, severe damage from the wind, or an ice storm.

Invertebrates     Animals that have no backbone or spinal column.

Leaching     Dissolving and carrying away substances from the soil or plants by water passing through the soil or over the surface of a plant.

Life history     A description of all important characteristics and events in the life of any   organism: life-span, number of young, habitat, enemies, etc.

Limiting factor     The part of an organism’s environment that keeps it from becoming more numerous.

Limnologist     A scientist who specializes in the study of bodies of fresh water and things living in them.

Litter     Plant and animal parts (e.g. leaves, limbs, feathers, frass) that have fallen to the surface of the ground.

Mammalogist     A scientist who specializes in the study of mammals.

Mammals     Warm-blooded animals that have hair or fur and whose young drink milk from their mother’s body.

Materials     Those substances (chemical elements and compounds) that are found in a system. In an ecosystem study, nutrient materials are of special interest.

Metabolism     The process of the continuous chemical reactions that occur in a living thing.

Microclimates     The average weather conditions (e.g. temperature, humidity, amount of sunlight) that occur in the immediate environment of an object or a living thing.

Microenvironment     The specific conditions and organisms that are found in the immediate vicinity of a living thing and that directly affect it.

Microhabitat     The specific physical conditions that exist in the close vicinity of a living thing. Microhabitat conditions may differ from general environmental conditions.

Microorganism      A tiny living thing not visible to the naked eye. See Organism.

Molecule     The smallest particle of an element or compound that can exist in the free state and still retain the characteristics of the element or compound.

Natural history     The scientific study of nature.

Nitrates     Chemical compounds that contain oxygen and nitrogen bound together in the ratio of three oxygen atoms to one nitrogen atom (NO3).

Nitrogen     A chemical element which occurs naturally by itself as a gas (78% of the Earth’s atmosphere), and which combines chemically with other elements to become part of nitrates, proteins, etc.

Nitrogen-fixing bacteria     Microorganisms that combine nitrogen atoms with other atoms or “fix” the nitrogen, making it available for other organisms to use.

Nutrient     A substance that living things can use for their growth and repair.

Nutrient budget     An analysis of the amount of nutrients entering, contained in, and passed on by living things in an ecosystem.

Nutrient cycling     The way in which nutrients move around through the ecosystem as in a food chain. See Intrasystem cycling.

Omnivores     Animals that have a varied diet, eating plants and animals and sometimes also detritus or carrion.

Organic     Composed of complex chemical substances built on the basis of chains of carbon atoms, these substances are the essential materials of all living things.

Organism     An individual living thing, such as a plant, animal, bacterium.

Ornithologist     A scientist who specializes in the study of birds.

Output     Materials and energy that leave a system.

Overpopulation     The presence of more individuals of a particular kind of living thing than the resources of an environment can support.

Oxygen consumption     The amount of oxygen taken in by a living thing to use in the chemical reactions that must occur to support life activities.

Paleobotanist     A scientist who specializes in the study of plant life which was on Earth in prehistoric times, using present-day evidence.

Parameters     Measurements of particular aspects of something being studied, such as the numbers of individuals in a population, the numbers in each age level, or the sex ratio.

Photosynthesis     The chemical process by which living things, mostly green plants, absorb light energy and build it into organic substances to be stored or used for growth and repair.

Phytoplankton     Microscopic green plants which are free-floating in water.

Pioneer     A kind of living thing that is among the first to colonize an environment newly made available to it by changes in that environment.

Pollution     Undesirable amounts of substances or energy added to an environment, usually by man’s activity.

Predator     An animal that overcomes other animals in order to eat them.

Prey     An animal that may be overpowered and eaten by another animal.

Primary consumer     An animal that eats plant material.

Primary production     The energy that is captured chemically by photosynthetic organisms. Net primary production is the energy stored in chemical form beyond the energy needed by the living thing to stay alive.

Recycle     To reclaim useful material from waste and reuse it.

Secondary consumer     An animal that eats other animals.

Sinks     A general science term meaning withdrawal of something from a system. In ecology the term is used by some researchers to describe the temporary removal of certain nutrients from the available nutrient supply. In climate science the term is sometimes applied to carbon dioxide sinks, in which carbon dioxide is caused to be captured and stored in a part of the environment (such as trees or the deep sea) as a tool to be used against global climate change.

Species     Indicates a class of individuals of a limited kind, having the same distinguishing characteristics and usually interbreeding only with their own kind.

Standing crop     All the organisms of a particular kind, or all the organisms taken together, that are present in a given area at a specific time.

Steady state     A balanced condition, so that an input to the system equals the output from the system, resulting in no observable change in the system.

Strip-cut     A forestry practice in which bands of trees are cut down, with alternating strips of trees left standing.

Succession     Over a period of time an orderly and gradual change in the plant and animal communities living in a specific area.

System     In ecology, any group of living things and the physical features around them that relate to each other with flows of material and energy in continuing reaction; a self-sustaining, self-regulating group of relationships. An open system is a system that gains and/or loses materials or energy. A closed system is a system that has no gains or losses of material or energy.

Taxonomist     A scientist who specializes in classification, or determining to which type of living thing a particular individual belongs.

Terrestrial     Having to do with land as opposed to water (aquatic).

Territory     An area in which an animal lives and which it will defend against others of its kind.

Tolerance     Ability of a living thing to survive in the presence of a specific material or condition.

Transect     A line through an area along which samples are taken in a study to determine some property or properties of that area.

Transpiration     The loss of water form leaves by evaporation.

Watershed     The land surface area that is drained by a given stream.

Weir     A small dam designed to be used in measuring the amount of water flow in a stream.

Windfall     Trees that have been blown over by strong windstorms.

Zoologist     A scientist who specializes in the study of animals.

Zooplankton     Tiny animal life floating freely in the water.