| A | B |
|---|
| abiotic components | Nonliving chemical and physical factors in the environment. |
| abyssal zone | The very deep benthic communities near the bottom of the ocean. This region is characterized by continuous cold, extremely high water pressure, low nutrients, and near or total absence of light. |
| aphotic zone | The part of the ocean beneath the photic zone, where light does not penetrate sufficiently for photosynthesis to occur. |
| benthic zone | The bottom surfaces of aquatic environments. |
| benthos | The communites of organisms living in the benthic zone of an aquatic biome. |
| biogeography | The study of the past and present distribution of species. |
| biosphere | The study of the past and present distribution of species. |
| biotic components | All the organisms that are part of the environment. |
| canopy | The uppermost layer of vegetation in a terrestrial biome. |
| climate | The prevailing weather conditions at a locality. |
| community ecology | The study of how interactions between species affect community structure and organization. |
| community | All the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction. |
| coral reefs | Warm water, tropical, ecosystems dominated by the hard skeletal structures secreted primarily by the resident cnidarians. |
| deep-sea hydrothermal vents | A dark, hot, oxygen-deficient environment associated with volcanic activity. The food producers are chemoautotrophic prokaryotes. |
| detritus | Dead organic matter. |
| dispersal | The distribution of individuals within geographic population boundaries. |
| ecosystem ecology | The study of energy flow and the cycling of chemicals among the various biotic and abiotic factors in an ecosystem. |
| estuary | The area where a freshwater stream or river merges with the ocean. |
| eutrophic | Pertaining to a highly productive lake, having a high rate of biological productivity supported by a high rate of nutrient cycling. |
| intertidal zone | The shallow zone of the ocean where land meets water |
| landscape ecology | The application of ecological principles to the study of land-use patterns; the scientific study of the biodiversity of interacting ecosystems. |
| landscape | Several different primarily terrestrial ecosystems linked by exchanges of energy, materials, and organisms. |
| limnetic zone | The well-lit, open surface waters of a lake farther from shore. |
| littoral zone | The shallow, well-lit waters of a lake close to shore. |
| mesotrophic | Lakes with moderate amounts of nutrients and phytoplankton productivity intermediate to oligotrophic and eutrophic systems. |
| microclimate | Very fine scale variations of climate, such as the specific climatic conditions underneath a log. |
| neritic zone | The shallow regions of the ocean overlying the continental shelves. |
| oceanic pelagic biome | Most of the ocean's waters far from shore, constantly mixed by ocean currents. |
| oceanic zone | The region of water lying over deep areas beyond the continental shelf. |
| oligotrophic lake | A nutrient-poor, clear, deep lake with minimum phytoplankton. |
| organismal ecology | The branch of ecology concerned with the morphological, physiological, and behavioral ways in which individual organisms meet the challenges posed by their biotic and abiotic environments. |
| pelagic zone | The area of the ocean past the continental shelf, with areas of open water often reaching to very great depths. |
| permafrost | A permanently frozen stratum below the arctic tundra. |
| photic zone | The narrow top slice of the ocean, where light permeates sufficiently for photosynthesis to occur. |
| population ecology | The study of how members of a population interact with their environment, focusing on factors that influence population density and growth. |
| population | A group of individuals of one species that live in a particular geographic area. |
| Precautionary Principle | A guiding principle in making decisions about the environment, it cautions to "look before you leap" or otherwise consider carefully the potential consequences of actions. |
| profundal zone | The deep aphotic region of a lake. |
| seascape | Several different primarily aquatic ecosystems linked by exchanges of energy, materials, and organisms. |
| thermocline | A narrow stratum of rapid temperature change in the ocean and in many temperate-zone lakes. |
| tropics | Latitudes between 23.5 degrees north and south. |
| turnover | The mixing of waters as a result of changing water-temperature profiles in a lake. |
| wetland | An ecosystem intermediate between an aquatic one and a terrestrial one. Wetland soil is saturated with water permanently or periodically. |
