4.2)Biodiversity Flashcards
(79 cards)
what is biodiversity?
measure of all the diff plant, animal, fungus nd microorganism species, the genes they contain nd ecosystem that they form
What is a species?
A grp of organisms that can interbreed nd produce FERTILE offspring
What is habitat biodiversity?
The range of habitats in which diff species can live
What are the common habitats found in the UK?
Sand dunes
Woodland
Meadows
Streams
How do you tell that one habitat is more diverse than the other when they have the same number of species?
NOT DIVERSE - contain 25 plant species but 1/2 dominate the whole area
DIVERSE - contain 25 plant species dotted fairly evenly in an area
What is {species richness} nd {species evenness}?
Richness - number of species
Evenness - degree to which they are represented
Why is it unrealistic to try and observe + count all species in a habitat?
Estimate suggests that there are billions of single-celled organisms per square meter of soil nd thousands of mites per square meter
What is one way to practically estimate the number of microorganisms in a habitat?
Culture some microorganisms on a nutrient medium in lab nd let them grow
How do you practically sample a habitat?
Select small portion of a habitat
Multiply number of individuals of species found
=
estimate number of individuals of species in entire habitat
What are the 5 types of sampling strategies?
Random (sample site is randomly selected e.g on map)
Non R- opportunistic (researcher samples area that they have prior knowledge on e.g knows that the site contains particular species)
Non R- stratified (dividing habitat into areas that look diff nd sampling them separately)
Non R -systematic (samples taken at fixed intervals across a habitat)
What are the adv & disadv of RANDOM SAMPLING?
✅
-ensures data is NOT biased
👎
-may not cover all areas of habitat equally = species w low presence overlooked = underestimate of biodiversity
What are the adv & disadv of NON-R OPPORTUNISTIC SAMPLING?
✅
-easier nd quicker than random
👎
-data may be biased
-presence of large/colourful species = researches include in sampling data = overestimate biodiversity of that habitat
What are the adv & disadv of NON-R STRATIFIED SAMPLING?
✅
-ensures all areas of habitat is sampled = no under-representation
👎
-e.g disproportionate number of samples in one area = researcher may increase number of samples in lower areas = over estimation
What are the adv & disadv of NON-R SYSTEMATIC SAMPLING?
✅
-shows clear link between the number of individuals of a species nd a environmental factor
e.g further away from pond = drier plants
👎
-only the species within the line/belt can be recorded = other species missed = underestimate biodiversity
what is a sample?
smaller proportion of the target population
what preparation is needed when sampling a habitat?
-suitable clothing + footwear
-apparatus
-appropriate keys to identify plants
-consider the # of samples
-results table
when do you calculate the value of percentage?
when the plants are too small or too many
what is a quadrat?
square frame
how is random sampling completed?
-generate random coordinates
-place quadrat on coordinates
-identify the plants found
-calculate percentage coverage
what is the equation for population size?
of organisms in quadrat X total size of area (sample area) / total area of quadrats
what is a transect used for?
effect of a change in a habitat on biodiversity
what are the 2 types of transects?
-line
-belt
how is a line transect used?
-line drawn through area
-record species touching the line
-fixed intervals
what is an advantage of using a line transect?
able to see the effect of a change
