| Term | Definition |
|---|---|
| 10% rule | An ecological principle stating that approximately 10% of the energy available at one trophic level is transferred to the next trophic level, with the remaining 90% lost. |
| energy transfer | The movement of energy from one trophic level to another through feeding relationships in an ecosystem. |
| laws of thermodynamics | Physical principles that explain energy transformations, including that energy cannot be created or destroyed and that energy tends to become less organized and available for work. |
| trophic level | The position an organism occupies in a food chain or food web, determined by the number of energy transfer steps from the primary producer. |
| Term | Definition |
|---|---|
| commensalism | A type of symbiosis in which one species benefits while the other species is neither helped nor harmed. |
| competition | The struggle between organisms in an ecosystem for limited resources such as food, territory, mates, and habitat. |
| mutualism | A type of symbiosis in which both species benefit from the interaction. |
| parasitism | A type of symbiosis in which one species (the parasite) benefits while the other species (the host) is harmed. |
| predator | An organism that hunts and eats another organism (prey) for food. |
| predator-prey relationship | An interaction between two species in which a predator organism hunts and consumes another organism (the prey) for food. |
| prey | An organism that is hunted and eaten by a predator. |
| resource partitioning | The use of resources in different ways, places, or at different times by different species to reduce the negative impact of competition. |
| symbiosis | A close and long-term interaction between two species living in an ecosystem. |
| Term | Definition |
|---|---|
| energy flow | The movement of energy from one trophic level to the next through an ecosystem, beginning with solar energy captured by producers. |
| feedback loops | Mechanisms in ecosystems where changes in one component affect other components, which can either amplify (positive feedback) or dampen (negative feedback) the initial change. |
| food chain | A linear sequence showing the transfer of energy and nutrients from one organism to the next, starting with a producer and moving through consumers. |
| food web | A model depicting interlocking patterns of multiple food chains that shows the complex flow of energy and nutrients among organisms in an ecosystem. |
| nutrient flow | The movement of chemical nutrients and elements through an ecosystem via food chains and food webs. |
| trophic level | The position an organism occupies in a food chain or food web, determined by the number of energy transfer steps from the primary producer. |
| Term | Definition |
|---|---|
| adapt | The process by which organisms develop traits or behaviors that allow them to survive and reproduce in their environment. |
| altitude | The elevation above sea level, which affects temperature and precipitation and influences biome characteristics. |
| biome | A large geographic area characterized by distinctive climate, vegetation, and animal communities adapted to those environmental conditions. |
| climate | Long-term patterns of atmospheric conditions, including average temperature and precipitation, over decades or centuries at a specific location. |
| desert | A terrestrial biome characterized by very low precipitation, extreme temperatures, and sparse vegetation adapted to arid conditions. |
| global climate change | Long-term shifts in global temperatures and weather patterns caused by increased concentrations of greenhouse gases in the atmosphere. |
| latitude | The angular distance north or south of the equator, which affects the intensity of solar radiation received at a location. |
| nutrient availability | The presence and accessibility of essential nutrients in soil that support plant growth and affect biome productivity. |
| savanna | A terrestrial biome with scattered trees and shrubs, grasses, seasonal rainfall, and warm temperatures year-round. |
| shrubland | A terrestrial biome dominated by low-growing woody plants and shrubs, typically with moderate precipitation and seasonal variation. |
| soil | The layer of weathered rock and organic material on Earth's surface that supports plant growth and varies among biomes. |
| taiga | A terrestrial biome characterized by coniferous forests, long cold winters, and short growing seasons, located at high latitudes. |
| temperate grassland | A terrestrial biome characterized by grasses and herbaceous plants, moderate precipitation, and temperature variations between seasons. |
| temperate rainforest | A terrestrial biome with high precipitation, moderate temperatures, and dense vegetation found in temperate regions. |
| temperate seasonal forest | A terrestrial biome with moderate precipitation, distinct seasons, and deciduous or mixed forests in temperate regions. |
| tropical rainforest | A terrestrial biome near the equator characterized by high precipitation, warm temperatures year-round, and high biodiversity. |
| tundra | A terrestrial biome at high latitudes or high altitudes with permanently frozen soil, low precipitation, and vegetation adapted to extreme cold. |
| Term | Definition |
|---|---|
| algae | The major photosynthetic organisms in aquatic biomes that form the base of aquatic food webs. |
| aquatic biomes | Ecosystems characterized by water environments, including both freshwater and marine systems. |
| coral reefs | Marine ecosystems built by coral organisms that provide habitat for diverse species and are sensitive to temperature changes, sediment, and fishing practices. |
| depth | The vertical distance of water in aquatic biomes, affecting light penetration and organism distribution. |
| estuaries | Transitional marine ecosystems where rivers meet oceans, with varying salinity levels. |
| freshwater biomes | Aquatic ecosystems with low salinity water, including streams, rivers, ponds, lakes, and freshwater wetlands. |
| freshwater wetlands | Freshwater ecosystems with saturated soil and shallow water, supporting specialized vegetation. |
| lakes | Large freshwater ecosystems with still water, typically deeper than ponds. |
| marine biomes | Aquatic ecosystems characterized by saltwater, including oceans, coral reefs, marshlands, and estuaries. |
| marshland | Marine or brackish wetland ecosystems with salt-tolerant vegetation. |
| nutrient availability | The presence and accessibility of essential nutrients in soil that support plant growth and affect biome productivity. |
| oceans | The primary reservoir of water at Earth's surface in the hydrologic cycle. |
| ponds | Small, shallow freshwater ecosystems with still water. |
| rivers | Large flowing freshwater ecosystems that transport water across landscapes. |
| salinity | The concentration of dissolved salts in water, affecting the distribution of aquatic organisms. |
| streams | Flowing freshwater ecosystems, typically smaller than rivers. |
| temperature | A measure of thermal energy that affects organism survival and is a key factor in ecological tolerance. |
| turbidity | The cloudiness or clarity of water, affecting light penetration in aquatic ecosystems. |
| Term | Definition |
|---|---|
| carbon cycle | The biogeochemical process by which carbon moves between the atmosphere, living organisms, soil, and water systems. |
| carbon dioxide | A greenhouse gas produced by combustion of fossil fuels and respiration; a principal contributor to global climate change. |
| cellular respiration | The metabolic process in living organisms that breaks down organic compounds and releases carbon dioxide back into the atmosphere. |
| decomposition | The process by which dead organic matter is broken down by microorganisms, releasing CO2 and other nutrients back into the environment. |
| fossil fuels | Non-renewable energy sources formed from ancient organic matter, including coal, oil, and natural gas, that release carbon dioxide when burned. |
| photosynthesis | The process by which plants convert carbon dioxide and light energy into organic compounds, removing carbon from the atmosphere. |
| reservoir | A storage location or system that holds compounds (such as nitrogen, phosphorus, carbon, or water) for varying periods of time in biogeochemical cycles. |
| sinks | Locations or systems that absorb and store substances (water, carbon, etc.) from the environment in biogeochemical cycles. |
| sources | Origins or locations from which substances (water, carbon, etc.) are released into the environment in biogeochemical cycles. |
| Term | Definition |
|---|---|
| ammonia | A nitrogen compound (NH₃) produced during nitrogen fixation that is available for uptake by plants. |
| atmospheric nitrogen | Nitrogen gas (N₂) present in the atmosphere, which is the major reservoir of nitrogen on Earth. |
| nitrogen cycle | The movement of nitrogen atoms and molecules between sources and sinks in the environment, including the atmosphere, living organisms, and soil. |
| nitrogen fixation | The process by which atmospheric nitrogen is converted into ammonia or other nitrogen compounds that plants can use and incorporate into plant tissue. |
| reservoir | A storage location or system that holds compounds (such as nitrogen, phosphorus, carbon, or water) for varying periods of time in biogeochemical cycles. |
| Term | Definition |
|---|---|
| ATP | Adenosine triphosphate, a biological molecule containing phosphorus that stores and transfers energy in cells. |
| DNA | A biological molecule containing phosphorus that stores genetic information in organisms. |
| phosphates | Compounds containing phosphorus that are absorbed by plant roots and incorporated into biological molecules. |
| phosphorus availability | The amount of phosphorus accessible to plants and algae in soils and aquatic systems, which limits their productivity. |
| phosphorus cycle | The movement of phosphorus atoms and molecules between sources and sinks in the environment, including rock, sediments, soil, organisms, and aquatic systems. |
| phosphorus-bearing minerals | Rock and sediment minerals that contain phosphorus as a major component and serve as the primary phosphorus reservoirs. |
| reservoir | A storage location or system that holds compounds (such as nitrogen, phosphorus, carbon, or water) for varying periods of time in biogeochemical cycles. |
| RNA | A biological molecule containing phosphorus involved in protein synthesis and gene regulation. |
| Term | Definition |
|---|---|
| groundwater | Water stored beneath Earth's surface in soil and rock layers, serving as a smaller reservoir in the hydrologic cycle. |
| hydrologic cycle | The continuous movement of water in its various solid, liquid, and gaseous phases between Earth's surface and the atmosphere, powered by solar energy. |
| ice caps | Smaller reservoirs of water stored as ice at Earth's poles and high elevations in the hydrologic cycle. |
| oceans | The primary reservoir of water at Earth's surface in the hydrologic cycle. |
| reservoir | A storage location or system that holds compounds (such as nitrogen, phosphorus, carbon, or water) for varying periods of time in biogeochemical cycles. |
| sinks | Locations or systems that absorb and store substances (water, carbon, etc.) from the environment in biogeochemical cycles. |
| sources | Origins or locations from which substances (water, carbon, etc.) are released into the environment in biogeochemical cycles. |
| Term | Definition |
|---|---|
| blue light | Wavelengths of light that penetrate deeper than 100 meters in clear water, affecting photosynthesis at greater depths. |
| gross primary productivity | The total rate of photosynthesis in a given area, representing all energy captured by photosynthesizers. |
| net primary productivity | The rate of energy storage by photosynthesizers in a given area after accounting for energy lost to respiration. |
| organic compounds | Carbon-containing molecules produced by living organisms, such as glucose and other carbohydrates. |
| photosynthesis | The process by which plants convert carbon dioxide and light energy into organic compounds, removing carbon from the atmosphere. |
| photosynthesizers | Organisms, primarily plants and algae, that perform photosynthesis to convert solar energy into organic compounds. |
| primary productivity | The rate at which solar energy is converted into organic compounds via photosynthesis over a unit of time. |
| red light | Wavelengths of light that are primarily absorbed in the upper 1 meter of water, affecting aquatic photosynthesis. |
| respiration | The metabolic process by which organisms break down organic molecules to release energy, producing CO2 as a byproduct. |
| solar energy | Energy from the sun in the form of light and heat that is captured by living organisms. |
| Term | Definition |
|---|---|
| biogeochemical cycles | Cycles that move matter (such as carbon, nitrogen, and phosphorus) through the biotic and abiotic components of ecosystems. |
| conservation of matter | The principle that matter is neither created nor destroyed but is recycled and transformed through biogeochemical cycles. |
| energy flow | The movement of energy from one trophic level to the next through an ecosystem, beginning with solar energy captured by producers. |
| high-quality energy | Energy in a concentrated, usable form (such as solar radiation) that ecosystems require for functioning. |
| matter cycles | The movement and recycling of chemical elements and compounds through ecosystems, demonstrating the conservation of matter. |
| producers | Organisms, primarily plants and photosynthetic organisms, that convert solar energy into chemical energy at the lowest trophic level. |
| trophic level | The position an organism occupies in a food chain or food web, determined by the number of energy transfer steps from the primary producer. |