B4 Community level systems Flashcards
What are ecosystems?
-Communities of organisms (biotic) interacting with the abiotic factors of their environment.
-Lots of different materials are cycled through an ecosystem.
What is a community?
All of the populations of different species that are living in a habitat together.
What is a population?
All the individuals from one species living in a habitat.
What is the difference between biotic and abiotic?
Biotic means living and abiotic means non-living.
What abiotic factors affect communities?
-Light intensity.
-Temperature.
-Moisture levels.
-Soil PH.
-Soil mineral levels.
-Direction and intensity of wind.
How does light intensity affect a community?
-Light is required for photosynthesis and the rate of photosynthesis impacts the rate of a plant’s growth.
-Plants can be food sources / shelter for many organisms.
How does temperature affect a community?
-Impacts rate of photosynthesis.
-Animals and plants have optimum temperatures.
How do moisture levels affect a community?
Plants and animals need water to survive.
How does soil PH affect a community?
Different plants will grow best in different soil acidities.
Why do soil mineral levels affect a community?
Plants require lots of mineral ions to grow healthily.
Why do wind direction and intensity affect a community?
Wind speed affects rates of transpiration and photosynthesis in plants.
What biotic factors affect communities?
-Food availability.
-New predators.
-New pathogens.
-Competition.
Why does food ability affect a community?
Organisms require food to survive and reproduce therefore populations thrive when there is a high food availability.
Why do new predators affect a community?
Not enough prey for the predators to feed on without wiping out a whole prey population therefore new predators disrupt balance in communities.
Why do new pathogens affect a community?
Populations have no immunity / resistance to new diseases which can lead to increased deaths unless resistance evolves.
Why does competition affect a community?
If some organisms are better at acquiring the shared resources than others, they will out compete the less adapted organisms until there’s no longer enough of them left to breed.
What is competition?
When different organisms compete for same resources in an ecosystem.
Why can competition limit population / community size?
-Limits population size if it occurs within a species.
-Limits community size if it occurs between different species.
What may plants compete for?
-Light.
-Space.
-Water.
-Mineral ions.
What may animals compete for?
-Space.
-Food.
-Water.
-Mating partners.
What is interdependence?
When the survival of some organisms within a community is dependent on other species within the same community.
What are examples of interactions that can create interdependence within a community?
-Predation.
-Mutualism.
-Parasitism.
-(Food, shelter and reproduction).
What is predation?
Biological relationship in which a member of one species consumes a member of another species.
What is mutualism?
Interaction between 2 organisms where both benefit as a result of their relationship.
What is parasitism?
Interaction between 2 organisms where only the parasite benefits and not the host.
Why can the removal / addition of species within a community greatly impact other populations?
Changes the prey / predator numbers.
What is a stable community? And why is it difficult to replace lost populations in one?
When all the biotic and abiotic factors of a community are in balance so population sizes remain roughly constant. This means that if populations are lost, they are hard to replace.
Why are mineral ions and water constantly being recycled through abiotic and biotic parts of an environment?
