T2 (Ecosystems) Definitions Flashcards
Species
A group of organisms with common characteristics that can interbreed to produce fertile offspring
Ecosystem
A community of interdependent organisms and the physical environment they interact with (Made up of biotic and abiotic components)
Producers / Autotroph
Plants that convert energy into matter (make their own food)
Consumers
Animals that eat plants or other animals (can’t make food themselves)
Decomposers
Organisms that breakdown waste into component parts for reuse (obtain food from breakdown of dead organic matter)
Population
A group of individuals of the same species living in the same area at the same time
Biotic
Living
Abiotic
Non-living
Habitat
The environment in which a species usually lives
Niche
The role an organism plays and the position it holds in the environment
Limiting Factors
The resources in the environment that limit the growth, abundance and distribution of organisms/populations in an ecosystem
Density dependent factors
Ones that affect the population only when it reaches a certain density
Density independent factors
Control populations no matter what the density of it is
Carrying Capacity
The maximum number of individuals of a species that the environment can sustainably support in a given area
Predation
Where one organism (the predator) hunts and kills another (the prey) in order to provide it with the energy for survival and reproduction
Herbivory
The consumption of plant material by an animal (Herbivores)
Parasitism
One species benefits at the expense of another - When an organism (the parasite) takes nutrients from another organism (the host)
Mutualism
Two organisms of different species exist in a mutually beneficial relationship
Intraspecific Competition
Occurs when members of the same species compete for a limited resource
Interspecific Competition
Where members of different species compete for a resource that they both need
Fundamental niche
The full range of conditions and resources in which a species could survive and reproduce
Realized niche
The actual conditions and resources in which a species exists due to biotic interactions
Community
A group of populations living and interacting with each other in a common habitat (multiple species)
Trophic Level
The position an organism (or group of organisms in a community) occupies in the food chain
Bioaccumulation
The increase in the concentration of a pollutant in an organism as it absorbs or it ingests it from its environment
Biomagnification
The increase in the concentration of the pollutant as it moves up through the food chain
Photosynthesis
The process by which green plants convert light energy from the Sun into useable chemical energy stored in organic matter
Respiration
The conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy
Pyramids of numbers
Records the number of individuals at each trophic level coexisting in an ecosystem
Pyramids of biomass
Represents the biological mass of the standing stock at each trophic level at a particular point in time measured in units such as grams of biomass
per square metre (g m–2)
Pyramids of productivity
Shows the flow of energy through each trophic level of a food chain over a period of time
Biomass
The mass of living organisms in a given area expressed as dry weight of mass per unit of area or g m–2
Productivity
The conversion of energy into biomass in a given time expressed as J m-2 yr-1. The rate of growth of plants and animals in the ecosystem.
Gross
The total amount of products made
Net
What is left over after losses. Ecosystem losses include respiration and fecal loss
Primary
To do with plants
Secondary
To do with animals
Net primary productivity (NPP)
NPP = GPP – R (Respiration)
The gain by producers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses
Gross secondary productivity (GSP)
GSP = food eaten – fecal loss
The total energy or biomass assimilated by consumers
Net secondary productivity (NSP)
NSP = GSP – R
Gross primary productivity (GPP)
All the biomass produced by primary producers in a given amount of time
Sustainable yield (SY)
The amount of biomass that can be extracted without reducing natural capital of the ecosystem.
Energy
Flows
Matter
Cycles
Succession
The process in which an area changes over time
Biome
A collection of ecosystems that are classified according to their predominant vegetation; they share similar climatic conditions and organisms that have adaptations to the environment
K-strategists
Produce very few offspring, but they increase the quality of them by investing in a lot of parental care
r-strategists
Focus on increased quantity of offspring at the expense of quality (little / no parental care)
Zonation
A spatial change in response to changing conditions // The arrangement or pattern of communities in bands in response to change in some environmental factor over a distance
Primary Productivity
The gain by producers (autotrophs) in energy or biomass per unit area per unit time.
Secondary Productivity
The biomass gained by heterotrophic organisms, through feeding and absorption, measured in units of mass or energy per unit area per unit time.
Net Secondary Production
The gain by consumers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses
Organic
Made from living matter
Inorganic
Made from non-living matter
Tricellular Model (of Atmosphere Circulation)
Explains
the distribution of precipitation and temperature, and
how these influence structure and relative productivity of di erent terrestrial biomes.
Climax Community
A community of organisms that is more or less stable
(i.e. in steady-state equilibrium), and is also in equilibrium with natural environmental conditions such as climate. It is the end- point of ecological succession.
Dichotomous Key
A stepwise tool for identification where there are two options based on different characteristics at each step. The outcome of each choice leads to another pair of options. This continues until the organism is identified.
Species Richness
the number of species in a community
Species Diversity
the number of species and their relative abundance in a given area or sample
Commensalism
Population Interaction where 1 benefits and there is no impact (pos or neg) on the other
Individual
A single organism of one species
Primary Succession
The colonisation of new land that is exposed by avalanches, volcanoes, or glaciers by pioneer organisms (starts from rocks)
Secondary Succession
The sequence of community changes that take place after a community is disrupted by natural disasters or human actions (start from soil & left over organisms)
Population Density
Number of individuals of each species per unit area
