Ecology: sampling the environment Flashcards
Biodiversity
A measure of the range of different species of organism living in an area
Community
The relationship between all the living species in an area
Ecosystem
The relationship between the living species and their habitat
Habitat
The place where an organism lives and breeds
Population
The number of organisms of a single species in a given habitat
Studying the environment using the apparatus to measure biotic(living) data
Distribution of plant or animal species
The study of environment to investigate the changes of distribution
From a hedge grow into the centre of a field and also indicate levels of biodiversity
Pitfall trap
A hole is dug to accommodate a container and a raised lid is placed on top to prevent entry of rain. The trap is then left fora period of time (24 hours). Useful for collecting small ground living animals like beetles.
Quadrat
This is a square frame that can be placed at a series of randomly chosen coordinates. The abundance of plant species is often measured in this way- if individual plants cannot be identified (grass) then percentage cover can be used. It can also be used for non mobile animal species like barnacles.
Pooter
A pooter allows small animals to be sucked into an observation chamber so that they can be easily identified.
Sweep net
Often used in long vegetation or in streams and rivers to catch small organisms for the purposes of identification
How to measure abiotic (non living) factors in the environment?
Light intensity: light meter Temperature: thermometer Wind speed: anemometer Water availability: moisture sensor pH: pH meter
How to avoid bias results when using quadrats
If choosen site is bias it would reduce the viability of the results obtained.
To avoid this the area is divided into a grid and random coordinates on the grid are generated( coordinates represent sampling points).
Belt transect
This technique is used when we can see a change in environment (sea to land).
It involves quadrats being laid end to end in a line(100m)
We would expect the change in environment to be reflected in the types of species recorded along the transect
Factors that will affect the numbers of organisms living in an area
- extent of cultivation( if ground is manages there are likely to be fewer species present/less biodiversity)
- space
- shelter
- presence of individuals to mate with
- predators
- mineral availability for plants
