Definitions Flashcards
Abiotic
Relating to a non-living feature of an ecosystem, such as light intensity, precipitation, temperature, wind speed or wind direction.
Adaptation
Any feature which makes an organism well suited to living in its environment.
Agrochemical
A chemical such as a fertiliser, hormone, pesticide or soil treatment that improves the production of crops.
What does Albedo measure?
The proportion of light that is reflected by a body or surface.
What is an Algal bloom?
A rapid growth of microscopic algae in water, often resulting in a coloured scum on the surface.
Describe Anaerobic digestion.
A process in which bacteria are used to decompose organic matter in an oxygen-free environment, producing biogas and sludge.
What does Anthropogenic mean?
Caused or influenced by human activity.
Define Anthropogenic greenhouse gas.
Emission of natural greenhouse gas enhanced by human activity. Includes water vapour, carbon dioxide, methane, nitrous oxide, ozone, and fluorocarbons (CFCs, HCFCs).
What is Aquaculture?
The rearing of aquatic animals or cultivation of aquatic plants for food.
Define Aquifer.
An underground layer of water-bearing permeable rock or drift deposits (sediments such as sand and gravel) from which groundwater can be extracted.
What is Assimilation?
The conversion of nutrients obtained from outside the body into a useful form that is incorporated into the tissues and organs.
What is an Autotroph?
An organism that can produce its own food; usually a green plant that produces its own food via photosynthesis, through the conversion of light energy into chemical energy.
What is Base flow?
Water that percolates downwards until it reaches the groundwater reservoir and then flows to surface streams as groundwater discharge.
Define Bauxite.
An ore rich in aluminium oxide, found in extractable quantities in areas associated with subduction zones.
What is Bioaccumulation?
The gradual build-up over time of a chemical or heavy metal in a living organism, through absorption via skin, gills or lungs.
What is Biocrude oil?
A biofuel obtained by heating dried biomass in an oxygen-free environment. Also known as pyrolysis oil or bio-oil.
Define Biodiesel.
A diesel fuel derived from oils and fats in animals or plants.
What is biodiversity?
The variety of species and ecosystems on Earth and the ecological processes of which they are part.
Biodiversity can be further categorized as ecosystem diversity, species diversity, and genetic diversity.
What is bioethanol?
An alcohol made by fermentation of carbohydrates from plant materials, which can be mixed with petrol as a fuel for vehicles.
What is biofuel?
Combustible biomass or a fuel derived from biomass.
What is biogas?
Gas produced through the fermentation of organic matter.
What is biological oxidation?
The process by which bacteria and other micro-organisms consume dissolved oxygen and organic substances in sewage.
What does biological oxygen demand (BOD) measure?
The amount of dissolved oxygen used by aerobic micro-organisms when decomposing organic matter in water.
What is biological weathering?
A form of physical weathering caused by animals, plants, fungi and micro-organisms.
What is biomagnification?
Arises through consumption of organisms containing bioaccumulated chemicals or heavy metals, transferring pollutants up the food chain.
What is biomass?
The mass of organisms in a given area or volume.
What is a biome?
A regional or global land area characterised by the plants, animals and climate in the area.
What is biomethanol?
A biofuel produced by gasification of biomass involving reactions using steam, intense pressure and limited oxygen.
What does biotic refer to?
Relating to a living feature of an ecosystem, such as competition, food supply, disease, predation.
What is a biotic index?
A scale showing the quality of an environment based on the types of organisms which inhabit it.
What is blackwater?
Waste water and sewage from toilets, which can be treated and recycled for non-potable use.
What characterizes brown earth soil?
Typically found under deciduous forest, with leaf litter resulting in rich humus and indistinct A- and B-horizon boundaries due to mixing by soil organisms.
What is capillary action?
The movement of soil moisture in any direction within soil as water moves through pore spaces from wet areas to drier areas.
What is capture-mark-recapture?
A method used in ecology to estimate the size of a population.
What is a carnivore?
An animal that obtains its energy by consuming other animals.
What is carrying capacity?
The maximum population size of a species that the environment can sustain indefinitely.
What is a catalyst?
A substance that increases the rate of a chemical reaction without undergoing any permanent chemical change.
What is chemical weathering?
Rainwater reacts with mineral grains in rocks to form new minerals (clays) and soluble salts. These chemical reactions occur particularly when the rainwater is slightly acidic.
This process alters the mineral composition of rocks.
Define circular economy.
An approach where resources, waste, emissions, and energy loss are minimised through use of long-lasting design, maintenance, repair, reuse, reprocessing, and recycling.
It aims to create a closed-loop system.
What is climate?
Large-scale, long-term weather patterns.
Climate is distinct from weather, which refers to short-term atmospheric conditions.
What is climate change?
A large-scale, long-term shift in Earth’s weather patterns or average temperatures. Encompasses global warming.
Climate change can result from both natural processes and human activities.
What is a climax community?
The final stage of succession, in which a community of plants and animals remains stable and exists in balance with each other and their environment.
Climax communities are typically diverse and resilient.
Define closed loop recycling.
Recycling of a material indefinitely without degradation of products, for example glass, aluminium.
This process allows for the continuous use of materials.
What is coagulation in wastewater treatment?
Chemical treatment of wastewater to separate out small suspended particles from the water.
Coagulation is often followed by sedimentation.
What is a community in ecology?
All the organisms that live together in an ecosystem.
Communities can vary in size and complexity.
What is competition in ecology?
An interaction that occurs between organisms whenever there is shared demand for a limited resource.
This can occur within a species (intraspecific) or between different species (interspecific).
What is condensation?
The process of a vapour or gas turning into a liquid.
This process is crucial in the water cycle.
What occurs at a constructive plate boundary?
This occurs where convection currents in the upper mantle are diverging, forcing the plates apart. Magma rises through the gap, creating new oceanic crust.
It is also known as a divergent boundary.
Define consumer in ecology.
Any organism that gains its energy from other organisms. Also known as a heterotroph.
Consumers can be primary, secondary, or tertiary.
What is a convection current?
A circulation pattern in which warmer low-density material rises and cooler high-density material sinks.
Convection currents are important in both atmospheric and oceanic processes.
What happens at a convergent plate boundary?
Two or more tectonic plates move together. See destructive plate boundary.
This can lead to the formation of mountains or subduction zones.
What is the core of the Earth?
The Earth’s inner core is solid, composed of an iron-nickel alloy, and surrounded by a liquid outer core of molten iron and nickel.
The core is responsible for Earth’s magnetic field.
What is the Coriolis effect?
The Earth’s rotation causes a deflection in the surface wind patterns and surface ocean currents across the globe.
It deflects winds to the right in the northern hemisphere and to the left in the southern hemisphere.
What is crop rotation?
The practice of growing different crops in succession on the same land, chiefly to avoid depletion of the soil but also to control weeds, diseases and pests.
This method improves soil health and reduces the need for chemical fertilizers.
What is the crust of the Earth?
The outer layer of the Earth. May be continental or oceanic, and comprise igneous, metamorphic or sedimentary rocks.
The crust is the thinnest layer of the Earth.
Define decomposer.
An organism that obtains its energy by breaking down dead organic matter, for example bacteria and fungi.
Decomposers play a crucial role in nutrient cycling.
What is decomposition?
The breaking down of organic materials into smaller constituent parts, especially by the action of decomposers.
This process releases nutrients back into the ecosystem.
What does density measure?
The number of individuals of the same species present per unit area or unit volume.
Density is a key factor in population ecology.
Density Dependant
Interactions between organisms which reduce the population when numbers are high and allow the population to increase when numbers are low
Density independent
Factors, usually natural disasters which reduce the reproduction rate or increase the death rate of organisms independently of population density
Deposition
The settling out of rock fragments and sediments after transportation by water, wind, ice or gravity
Desalination
The process of removing salt from sea water
Desert
An area that receives less than 25cm average annual precipitation
Desertification
The process by which fertile land becomes desert
Destructive plate boundary
This occurs where convection currents in the upper mantle are converging, forcing the plates above to move towards each other. The denser plate subducts below the less dense plate resulting in a net loss of crust
Detritivore
An animal that obtains its energy by consuming dead organic matter. Eg Wood louse, Earth worms, maggots
Diffuse pollution
Pollution that arises from land activities spread across large areas and have no specific point of discharge
Dissolved oxygen concentration
A measure of the amount of free oxygen dissolved in water, which can be used to determine the quality of water and assess its ability to support life
distribution
The manner in which a group is arranged geographically. Can change seasonally, in response to resource availability and in response to other external factors
District heating scheme
A network of pipes used to deliver heat (hot water or steam) from point of generation to an end user
Divergent plate boundary
Two or more tectonic plates move apart
Diversification
This is the branching out from traditional farming by adding new money making activities. Eg specialist crops or BnB or play park
Diversity index
A measure of species diversity in a community or area. Takes relative species abundance into account and provides more information about community composition than simply species richness
Drip irrigation
A method if controlled irrigation in which water is slowly delivered to the root system of plants, either dripped onto soil surface or directly onto roots
Earthquake magnitude
Earthquakes generate vibrations, known as seismic waves. The magnitude or size of an earthquake can be estimated from amplitude and length of a seismic wave.
Ecosystem
A natural biological unit made up of living and non living parts ie the community and the habitat
Ecological efficiency
The percentage of biomass produced by one trophic level that is transferred and incorporated into biomass at the next trophic level
