B15 Ecology Flashcards
Habitat
The part of an ecosystem where an organism lives.
Species
This is a group of organisms that can
breed together to produce fertile offspring.
Population
This is the organisms of the same species that share a particular habitat.
Community
This is made up of all the organisms that share a particular habitat.
Competition
A word that describes the fact that organisms often need the same resources
Interderpendant
A word that describes
how organisms rely on
and impact upon each
other.
Biotic factors
Other living things that can affect a particular population. E.g a new pathogen or parasite
Abiotic factors
Non-living things that can affect a particular population e.g light intensity
Temperature
- Can limit photosynthesis and therefore growth in plants
- Cold climates can affect numbers of herbivores that can survive and so the number of carnivores in the community
Moisture levels
- If there is no water there will be little or no life
- After rain many plants grow ,flower and seeds very quickly while water is available.
Soil pH
- The level of mineral ions, for example, nitrate ions , has a considerable impact on the distribution of plants.
- The nitrates plants need are provided when they break down the animal protein
- Most other plants struggle to grow in areas with low levels of mineral ions.
- The pH of soil also has major effect on what can grow in it and on the rate of decay and therefore on the release of mineral ions back into the soil
Wind intensity
-The whole landscape is affected by the wind. It also means that plants transpire fast.
Availiabilty of oxygen
- the availability of oxygen has a huge impact on water - living organisms with very low oxygen levels
- The proportion of oxygen in the air varies very little
Availability of carbon dioxide
-The level of carbon dioxide acts a limiting factor for photosynthesis and plant growth. It can also affect the distribution of organisms.
Light intensity
Can limit photosynthesis so affects distribution of plants and animals
Breeding cycles of many animals and plants is linked to day length and light intensity
Food availability
When there is lots of food, organisms breed more easily