Biodiversity Flashcards
Biodiversity definition
It’s a measure of the variety of living organisms in a particular area.
Species biodiversity component
Species richness and species evenness
Species richness definition
Number of different species present in a particular area
Species evenness definition
A comparison of the number of individuals in each species present in a particular area
Genetic biodiversity
The variety of different genes that make up a species.
Habitat biodiversity
Number of different habitats found within an area
Random sampling
Selects individuals by chance, so that every individual has an equal chance of being chosen
Non-random sampling
- Opportunistic
- Stratified
- Systematic
Opportunistic sampling
- weakest form => biased data
- uses the conveniently available sample
Stratified sampling
- population is divided into strata based on particular characteristic (eg: gender)
- strata sampled separately in proportion to their part of the habitat as a whole
Systematic sampling
- samples are taken at fixed intervals
- line transect or belt transect can be used
Sampling animals techniques
- porter (small insects)
- sweep nets (insects in long grass)
- pitfall traps (crawling invertebrates)
- tree beating (invertebrates in trees)
- kick sampling (organisms in rivers)
Sampling plants techniques
- point quadrant
- frame quadrant
Measurements using the frame quadrant
percentage cover
density
frequency
Simpson’s Index of Diversity
D= 1-(sum(n/N)^2)
0
Abiotic factors and associated sensors
pH - pH meter light intensity - light meter temperature - thermometer oxygen content in water - dissolved oxygen probe wind speed - anemometer relative humidity - humidity sensor
Allele
Different version of the same gene
Importance of genetic biodiversity
If genetic biodiversity is high, there are more chances of survival of organisms because they are more likely to be able to adapt to changes in their environment due to the present of a higher number of different genes
Factors affecting genetic biodiversity
- mutations
- selective breeding
- interbreeding b/n different populations
- captive breeding (in zoos)
- rare breeds
- artificial cloning
- natural selection
- genetic bottlenecks (few individuals of a population survive an event or change)
- founder effect (when populations are geographically isolated)
- genetic drift (random nature of alleles being passed on from parents)
Polymorphism
proportion of polymorphic genes=number of polymorphic gene loci/total number of gene loci
Types of conservation
ex situ
in situ
Keystone species
Species that play an important role in maintaining the structure of an ecosystem
