Factors Affecting Abundance And Distribution Flashcards
What is an ecosystem
All the organisms living in a particular area and all the non-living(abiotic) factors
What is a habitat
The place where an organism lives
What is a population
All of the organisms of one species in a habitat
What is population size
The number of individuals of one species in a particular area
What is a community
All of the organisms of different species that live in the same habitat and interact with each other
What are abiotic factors
The non-living features of the ecosystem
What are biotic factors
The living features of an ecosystem
What is abundance
The number of individuals of one species in a particular area-dependent on abiotic and biotic factors
What is distribution
Where a species is within a particular area
Examples of factors that affect abundance of species
Sunlight, space, water availability, carbon dioxide and oxygen, temperature
How does abundance vary because of abiotic factors and example
-factors need to be ideal for a species for organisms to grow fast and reproduce successfully
-eg when temp of a mammals surroundings are ideal for metabolic reactions they don’t have to use up as much energy maintaining their body temp meaning more energy for growth and reproduction so population size increases, if temp not ideal will have to use a lot of energy to maintain right body temp, less energy for growth and reproduction and population size decreases
Three ways abundance varies due to biotic factors
-Interspecific competition
-intraspecific competition
-predation
What is interspecific competition
Competition between different species for the same resources, means both populations will be smaller than if only one species there as less energy for growth and reproduction
What is intraspecific competition
-competition between organisms of the same species for the same resources
-population increases when resources plentiful meaning more organisms competing for same amount of resources, eventually resources limiting and population begins to decline, smaller population means less competition which is better for growth and reproduction so pop starts to grow again
What is carrying capacity
The maximum stable population size of a species that a habitat can support
What is predation and How does predation affect abundance
When an organism kills and eats another organism-predator and prey populations are interlinked as if population of one changes it causes the population of the other to change
-as prey pop increases there’s more food for predators so their pop increases, as predator pop increases more prey is eaten so prey population begins to fall meaning less food for predators so their pop decreases and this repeats
Why does distribution vary because of abiotic factors and examples
-organisms can only exist where the abiotic factors they can survive in exist
-eg some plants don’t grow near shoreline as soil too salty/large trees can’t grow in polar regions as temp too low
How do biotic factors affect distribution
-interspecific competition can affect distribution of species eg if two species competing but one is better adapted to its surroundings, less well adapted species is likely to be out competed and it won’t be able to exist alongside the better adapted species
What is a niche
The role of a species within its habitat, includes its biotic and abiotic interactions, each species has its own unique niche which can only be occupied by one species
How can abundance be explained by the niche concept
Two species occupying similar niches will compete so fewer individuals of both species able to survive in the area
How can distribution be explained by the niche concept
Organisms can only exist in habitats where all the conditions that make up their role exist
