[19.1] populations and ecosystems Flashcards
key definitions
what is ecology?
the study of the inter-relationships between organisms and their environment, which includes abiotic and biotic factors
what is an ecosystem?
- made up of a community and all the non-living factors of its environment
- interaction between abiotic and biotic factors in a given area
what is a population?
the number of members of a given species in a specific habitat at the same time
what is the carrying capacity?
the maximum sustainable population of a species in an ecosystem given the available resources
what is the carrying capacity determined by?
a combination of all factors in an ecosystem eg. predation, inter / intraspecific competition
how can the size of a population vary?
- effect of abiotic factors
- interactions between organisms eg. intra / interspecific competition and predation
what is a community?
all of the populations of different species in a given habitat living and interacting at the same time
what is a habitat?
where an organism normally lives
what is a niche?
- how can organism fits into the environment
- where an organism lives and what it does there
- inclues all the biotic and abiotic conditions an organism is adapted to survive in, reproduce and maintain a viable population
what is the competitive exclusion principle?
the idea that no two species occupy exactly the same niche
what are biotic factors?
- living aspects of an ecosystem
- almost the same as community
what are abiotic factors?
- non-living aspects of an ecosystem
- influences biotic factors
- determines what organisms can live in an ecosystem
what are some examples of abiotic factors? (10)
- wind
- light intensity
- wavelength of light absorbed by pigments for photosynthesis
- soil pH
- soil water content
- soil mineral content (eg. nitrates, phosphates)
- soil structure
- oxygen concentration
- carbon dioxide concentration
- rain levels
in what ways can biotic factors affect abiotic factors? (4)
- competition
- predation
- parasites
- mutualism
what is a potential niche?
the range of conditions in which a species could theoretically survive which is set by abiotic factors only