Ecology
What is a population?
Total number of a species in a habitat
If prey numbers fall, what would you predict to happen to predator numbers?
Also fall due to lack of prey (food)
Two different species competing is called?
Inter-specific competition
What instrument is used to measure light intensity?
Light meter
What apparatus is used to sample plants?
quadrats
What is biodiversity?
The variety and abundance of organisms in an ecosystem
What is a producer?
An organism that produces its own food (typically a plant)
Two of the same species competing is called?
Intra-specific competition
Give an example of 2 abiotic factors
temperature, light intensity, pH, moisture
What sampling techniques can be used to sample small invertebrates
pitfall trap or tree beating
Organisms that can reproduce to produce fertile offspring
What do the arrows in a food chain show?
The flow of energy
When does competition occur?
When resources are in short supply
Give a biotic factor
grazing, disease, predation, competition, food availability
Why should several quadrats be used rather than one?
To increase the reliability of the results
What is a community?
All the living organisms that live within a habitat
What is meant by an organisms niche?
The role of the organism in the community (it includes its interactions with other organisms and the conditions that it needs to survive)
Name two resources plants may compete for
light, water/moisture, nutrients, space
lichen, mayfly nymph, water louse, ....
What is an error that can occur with pitfall traps and how can you overcome this?
level to the ground, cover, check regularly, holes in the bottom
What is an ecosystem?
The community of organisms living in a habitat and the non-living components with which they interact
Give 2 things that could part of an organisms niche?
food/resources required, predation, competition, light availability, nutrients, temperature
Which type of competition is more intense and why?
Intra-specific competition because they occupy the same niche
What is an indicator species?
A species whose presence of absence indicates pollution/environmental quality
What is a possible source of error for tree beating?
Animals fly away, may still be on the branch, sample may not be representative