Topic 7:Ecology Flashcards
Abiotic factors
The non-living aspects of an ecosystem e.g. temperature, light intensity, moisture, wind direction, wind intensity, soil pH, soil mineral content, carbon dioxide levels
and oxygen levels.
Adaptation
A feature of an organism that increases its chance of survival in its environment.
Such features may be behavioural, structural or functional.
Anaerobic decay
Decomposition in the absence of oxygen (commonly occurring in waterlogged soils) that produces carbon dioxide and methane gas.
Apex predator
A carnivore at the top of the food chain with no predators.
Biodiversity
The variety of living organisms in an ecosystem
Biogas
A type of biofuel (methane gas) produced by anaerobic decay in biogas generators.
Biotic factors
The living components of an ecosystem e.g. food availability, pathogens, predators and other species.
Carbon cycle
The cycle through which carbon (in the form of carbon dioxide) moves between living organisms and the environment, involving respiration, photosynthesis and
combustion.
Community
All of the populations of different species living together in a habitat
Competition
When different organisms compete for the same resources (e.g. light, water, mates, territory) in an ecosystem. This limits population sizes and stimulates evolutionary
change.
Compost
Dead and decaying organic matter, commonly used as a fertiliser.
Decomposers
Organisms that release enzymes which catalyse the breakdown of dead
plant and animal material into simpler organic matter.
Decomposition
The breakdown of dead materials into simpler organic matter. The rate of decomposition is affected by temperature, water and oxygen availability
Deforestation
The removal of trees from land which is subsequently used to grow crops or provide space for cattle.
Distribution
The spread of living organisms in an ecosystem. It is affected by environmental changes which may be seasonal, geographic or man-made
Ecosystem
The community of organisms (biotic) and non-living (abiotic) components of an area and their interactions
Efficiency of biomass transfer
The efficiency of biomass transfer between trophic levels is
calculated using: efficency=biomass available after transfer/biomass available before transfer x100
Extremophiles
Organisms that can live in extreme environments e.g. high temperatures, high salinity.
Food chain
Food chain: Describes the feeding relationships between organisms and the resultant
stages of biomass transfer. It takes the form:
producer ⟶ primary consumer ⟶ secondary consumer ⟶ tertiary consumer
Food security
Ensuring that populations have access to adequate amounts of safe and nutritious food.
Global warming
The gradual rise in the average temperature of the Earth due to increasing atmospheric levels of carbon dioxide and methane gas
GM crops
Crops that have had their genomes modified by the insertion of a desired gene
from another organism.
Interdependence
The dependence of different organisms on each other for survival e.g.
plants depend on pollinators, herbivores depend on plants.
Microorganisms
Very small organisms involved in the recycling of materials in an ecosystem. They return mineral ions to the soil and convert carbon to carbon dioxide which is released into the atmosphere.
Mycoprotein
A food high in protein (suitable for vegetarians) that is produced by the
microorganism, Fusarium, in fermentation vats
Peatlands
Areas of peat soil in wetland habitats formed by the accumulation of partially decayed organic matter. Peat is commonly used as a garden compost.
Pollution
Contamination or destruction of the natural environment due to human
intervention
Population
All organisms of the same species living with one another in a habitat.
Predators
Consumers that prey on and eat other animals
Prey
Animals that are eaten by predators.
Primary consumers
Herbivores that consume producers at trophic level 2 of a food chain.
Producers
Photosynthetic organisms (e.g. green plant or alga) at the start of the food chain that provide biomass for all living things.
Pyramid of biomass
A table of the dry mass of living material at each trophic level of a
food chain. This forms the shape of a pyramid.
Quadrat
A square grid of known area used in sampling to determine the abundance and distribution of organisms in an ecosystem.
Secondary consumers
Carnivores that consume herbivores at trophic level 3 of a food chain.
Sustainable
The ability to maintain something for future generations.
Sustainable fisheries
Methods of harvesting fish at a sustainable rate and increasing fish stocks, for example, by controlling net size or introducing fishing quotas.
Tertiary consumers
Carnivores that consume other carnivores at trophic levels 4 and above of a food chain.
Transect
A line along an area used in sampling to determine the abundance and distribution of organisms in an ecosystem.
Trophic level
The position of an organism in a food chain.
Water cycle
The cycle through which water moves between living organisms and the environment, involving evaporation, transpiration, condensation and precipitation.
