18- biodiversity Flashcards
biological species concept
organisms within species are able to reproduce+produce fertile offspring
- reproductively isolated from other species
morphological
physical features in species
ecological species concept
defines species by ecological niche- way interacts with environment
living in same area at same time
suggest when the morphological species concept is more useful than the biological
- extinct organisms- can’t analyse DNA
- for organisms breeding asexually
- when morphological diffs are easier to determine- it’s often difficult to observe reproductive behaviour
phylogenetic group
organisms in a group due to their evolutionary history/relationships OR due to their common ancestors
how to classify viruses
[What disease caused]
Type of nucleic acid(RNA/DNA)
Whether genetic material is single/double stranded
biodiversity
variety of ecosystems+species in area+genetic diversity within each species
ecosystem
relatively self-contained, interacting community of organisms+biotic/abiotic factors, and the environment in which they live
linked by food webs
interdependence between organisms+environments
community
all living organisms of species found in ecosystems at particular time
niche
role of organisms+how it fits in an ecosystem
includes: habitat, how it obtains energy
species diversity (includes diff species+numbers)
number of species and the number of individuals in each species(evenness of abundance)
species richness
total number of different species in a habitat.
quantified by taking random samples and counting the species present.
higher species richness indicates greater diversity
species evenness
comparison of the numbers of individuals of each species in a community.
measured by taking samples and counting individuals of each species.
More even abundances mean higher species evenness and diversity
genetic diversity
diversity of alleles+genes in genome of species
3 levels of biodiversity
- ecosystems/habitat variation
- number of diff species + relative abundance
- genetic variation within each species
how does ecosystem variation contribute to biodiversity
- more differing species
- diff habitats
- diff niches
- diff selection pressures
- genetic diversity
- diff climate
- adaptation
random sampling
involves quadrats (calc species density/frequency, percentage cover)
- Choose an area.
- Randomly generate coordinates across the area - prevents sampling bias by removing human involvement in choosing samples.
- Collect samples from random coordinates - This gives us samples that are representative of the population.
- Repeat this several times - This gives us a large sample size and minimises the effects of chance.
- Analyse the data collected - identify any relationships
Simpson’s diversity index
- total number of organisms of particular species
- total number of organisms from ALL species
sampling biodiversity
- Choose an appropriate method (e.g. quadrats, pooters, etc.) depending on the habitat.
- Estimate the number of individuals of each species in a sample.
- Repeat sampling across habitat and take multiple samples for reliability.
- Estimate total number of individuals or species in the area.
systematic- when change in physical conditions
involves line/belt transects
positions of the sampling points are chosen by the person carrying out sampling
possibility that person choosing could show bias towards or against certain areas
Individuals may deliberately place the quadrats in areas with the fewest species as these will be
easier and quicker to count
- unrepresentative of the whole area
line transect (organism species)
lay measuring tape in straight line across sample area
at equal distances along the tape record the identity of the organisms that touch the line. e.g. every 2m
qualitative data produced
belt transect (abundance)
Place quadrats at regular intervals along the tape and record the abundance of each species within each quadrat
produces quantitative data
method to estimate pop size of mobile animal
mark-release-recapture
capture sample+count(humane traps)
mark without adversely affecting rats(tagging/using dyes)
return to where they were caught
allow time to mix with pop
capture second sample
count number caught+number marked
pop size estimate=number in 1st sample x number in second sample / number in second sample marked
repeat
measuring abiotic factors
Light, humidity, and temperature (using sensors).
pH and wind speed (using probes).
Dissolved oxygen (using specialised probes
