5.1 Flashcards
What is the part of the atmosphere inhabited by living organisms called
The biosphere
Define abiotic factor
Physical and chemical factors e.g. Light intensity
Define biotic factor
Factors determined by other organisms such as predation and competition
Define habitat
Place with a distinct set of conditions were an organism lived
Define population
A group of individuals of the same species found in an area
Define community
Made up of populations sharing a habitat or ecosystem
Define producer
An organism that is able to synthesise complex organic molecules from simple inorganic molecules through photosynthesis or chemosynthesis
Define consumer
An organism that obtains food from feeding on other organic matter
Define ecosystem
An ecological unit that consists of the living organisms and the abiotic factors that influence them
Define niche
The role of an organism within its habitat
Define succession
The way a community changes overtime and the variety of species that change in a community is known as succession
What is primary succession
Starts in newly formed habitats where there had never been a community before
What is the process of succession
1) first organisms to colonise an area are known as pioneer species
2) they change the environment making it suitable for other organisms
3) as more organic matter is deposited in the soil, the soil can hold more water which allows rooted plants to establish
4) larger plants compete with current organisms, replacing the current community
5) eventually a community dominated by trees develop, forming a stable climax community
How do pioneer species work and give an example
They have characteristics that allow them to survive with limited nutrients and water
They grow then die back, depositing organic matter and nutrients into the soil
What is secondary succession
Occurs on bare soil where an existing community has been cleared
If undisturbed, it would lead to the establishment of a forest climax community in the uk
What is deflected succession
A community that only exists and remains stable due to human activity which prevents succession
Define gross primary productivity
The rate at which energy is incorporated into organic molecules
Define net primary productivity
Rate at which energy is transferred into new plant biomes per m per year
What is the equation and units for NPP
NPP = GPP - R
KJ / m / year
