Key Environmental Concepts: A Glossary
Albedo
Albedo is the percentage of solar radiation reflected by the Earth back into space. A higher albedo means more reflection and lower temperatures. Areas covered by snow or ice have high albedos.
Hydrologic Balance
Hydrologic balance refers to the equilibrium between water inputs (precipitation) and outputs (evapotranspiration and runoff) in a given area. A balance exists when inputs equal outputs. A deficit occurs when outputs exceed inputs, depleting water reserves. A surplus occurs when inputs exceed outputs.
Bioaccumulation
Bioaccumulation is the process where toxic substances accumulate in the bodies of organisms higher up the food chain. This occurs because some pollutants are difficult to eliminate and become concentrated as they move through trophic levels.
Bioindicators
Bioindicators are species used to assess environmental quality. Their presence, absence, or population changes indicate pollution levels, reflecting their sensitivity to specific contaminants.
Climate Change
Climate change refers to long-term shifts in global temperatures and weather patterns. Primarily caused by human activities releasing greenhouse gases, it leads to melting ice, rising sea levels, and ecosystem disruption.
Ecological Flow
Ecological flow (also known as environmental flow) is the minimum amount of water left in a river to sustain ecosystems. It’s the portion not extracted for human use. In Spain, the ecological flow is set at 10% of the normal flow.
Climax Community
A climax community is the final stage of ecological succession, representing a stable ecosystem. Nutrient recycling is regular, and species populations remain balanced. Biodiversity and biomass are high, but productivity decreases.
Biodiversity
Biodiversity encompasses the variety of life within an ecosystem. It includes species diversity, genetic diversity within species, and ecosystem diversity.
Ecosystem
An ecosystem is a natural system comprising living organisms (biocenosis) and their physical environment (biotope), along with their interactions.
Greenhouse Effect
The greenhouse effect is a natural process that keeps Earth’s average temperature around 15°C. Certain atmospheric gases trap infrared radiation emitted by the Earth’s surface, retaining heat.
Eutrophication
Eutrophication is the excessive nutrient enrichment of water bodies, often due to agricultural or urban runoff. This leads to increased productivity, but also alters ecosystems, affecting biodiversity and water quality.
Factors Limiting Primary Production
These are environmental factors that restrict the growth of producers (plants and algae) in an ecosystem. Key limiting factors include phosphorus, temperature, and water availability.
Susceptibility
Susceptibility refers to the amount of a pollutant present in a specific location after its release, transport, and transformation. It determines the exposure of living organisms and materials to the pollutant.
Oil Spills
Oil spills are a severe form of marine pollution, particularly from tanker accidents. Oil forms a surface film and coats the seabed, harming marine life, fisheries, and tourism.
Hydrological Planning
Hydrological planning involves managing water resources to ensure sustainable use. It includes strategies for water allocation, consumption reduction, and supply augmentation.
Biotic Potential
Biotic potential (represented by ‘r’) measures the potential change in population size over time. Excluding migration, r equals the birth rate minus the death rate.
Primary Production
Primary production measures the biomass produced by autotrophic organisms (producers) per unit of time. It’s influenced by factors like light, temperature, water, nitrogen, and phosphorus.
Residence Time
Residence time is the average duration a pollutant remains in the atmosphere. It varies depending on the pollutant’s properties and atmospheric conditions.