4.2 Biodiversity Flashcards
What is biodiversity ?
The number of different ecosystems and habitats in an area, the number of species in those ecosystems, and the genetic variation within each species.
What is a habitat?
Where an organism lives.
What is a species ?
A group of organisms of common ancestry that can interbreed to give fertile offspring.
What is habitat biodiversity ?
Number of different habitats (Inhabited area) in an area. Includes abiotic and biotic factors.
What are some examples of abiotic factors ?
Temperature, light intensity, soil pH, humidity.
What are some examples of biotic factors?
Food webs, competition, predators.
What is species biodiversity ?
Number of different species (species richness) and abundance of each species (species evenness).
What is genetic biodiversity ?
Variation of alleles within a species or population. The greater the genetic biodiversity, allows for better adaptation and species resistance to disease.
What is sampling ?
Taking measurements of a limited number of individual organisms present in a particular area.
What must sampling be representative of ?
1) Size of area or length of transect.
2)Incorporation of repeat measurement
3) Accounting for different times of the year.
How are quadrats used to asses abundance ?
1) Species frequency is calculated as the percentage of quadrats that include each species.
2) Species density is there number of individual organisms within a quadrat.
3) Percentage cover is the percent of an area of a quadrat in which the plant or animal occurs. Good for species such as grass.
What is random sampling ?
Taken to avoid any bias in location for sampling and can be done in a number ways including dividing the area into a grid and using a random number generator to determine coordinates. Equal probability of being chosen.
What is opportunistic sampling (non-random) ?
Weakest form of sampling where the researcher makes decisions based on prior knowledge. Researcher may deliberately sample an area containing a particular species.
What is stratified sampling (non-random) ?
Where habitat is divided into 2 areas, which appear different and sampling each area separately.
What is systematic sampling (non-random) ?
Where samples are taken at fixed intervals across the habitat. Eg., using a belt transect, line transect. Used to investigate effect of a changing factor.
What is an advantage and disadvantage of random sampling ?
Advantage = reduces bias as everything has an equal probability of being chosen.
Disadvantage = Time consuming and may only cover one area.
What is an advantage and disadvantage of opportunistic sampling ?
Advantage = More chances species being present.
Disadvantage = Weakest form of sampling that is likely to be biased.
What is an advantage and disadvantage of stratified sampling ?
Advantage = Takes all areas into account of different species.
Disadvantage = Over-representative of 2 areas and leads to a biased sample.
What is an advantage and disadvantage of systematic sampling ?
Advantage = more representative of area.
Disadvantage = biased sample.
What is a beating trap ?
Large white sheet placed on ground below a tress and tree is then shaken to dislodge the animals and insects.
What is a pooter ?
Scientists use to suck a small insects into glass jar.