4.2.1 - biodiversity 🌲 Flashcards
biodiversity
the variety of living organisms present in an area
habitat biodiversity
the number of different habitats found within an area
species richness
the number of different species living in a particular area
species evenness
comparisom of the number of individuals of each species living in a community
genetic biodiversity
refers to the variety of genes that make up a species.
importance of biodiversity
essential for the processes that support all life on Earth
impact of genetic biodiversity
csn lead to quite different characteristics being exhibited, e.g dog breeds
more genetic biodiversity allows for better adaptation to a changing environment
sampling
taking measurements of a limited number of individual organisms present in a particular area
abundance
number of species in a specific area at any time
random sampling
sample that fairly represents a population because each member has an equal chance of inclusion, selecting individuals by chance
random sampling steps
mark out a grid on the grass using two tape measures
use random numbers to determine coordinates
take a sample at each of the coordinate pairs
opportunistic non random sampling
uses organisms that are conveniently available - not representative of the population
stratified non random sampling
some populations can be divided into a number of groups based on a particular characteristic and then a random sample is taken
line transect
a line is marked along the ground and samples are taken at specified points
sampling bias
selection process might be biased. this can be reduced by using random sampling
chance reducing reliability
organisms selected may not be representative of the whole population
pooter
used to catch small insects. by sucking on a mouthpiece insects are drawn into the holding chamber via the inlet tube
sweep nets
used to catch insects in areas of long grass
pitfall traps
used to catch small crawling invertebrates
hole dug into ground which insects falls into
must be deep enough
trap covered so it does not fill up with rainwater
tree beating
used to take samples of the invertebrates living in a tree/bush
large white cloth stretched out under the tree
tree is shaken
animals will fall on to the shet
quadrats
square frames used in estimating abundance in plants or slow mothing animals
capture-mark-recapture
ecological surverying technique used to measure animal populations, in which individual animals are captured, marked and released, after a time the populatiom is re sampled and the number of marked animals caught gives an indication of population size
anemometer
instrument used to measure wind speed
advantages of abiotic factor sensors
- rapid changes can be detected
- human error is reduced
- high degree of precision can be achieved
- data can be stored and tracked on a computer
simpson’s diversity index
= 1 - ( sum of (n/N)^2)
importance of genetic biodiversity
species that have a greater genetic biodiversity are more likely to be able to adapt to changes in their environment and less likely to become exinct
factors that increase genetic biodiversity
- mutations in DNA of organism, creating new alleles
- interbreeding between different populations, causing alleles to be transferred
selective breeding
process of selecting a few organisms with desired traits to serve as parents of the next generation, decreasing genetic biodiversity
captive breeding programmes
raising and breeding organisms in controlled conditions, such as zoos or aqauariums, decreasing genetic biodiversity
deforestation affecting biodiversity
directly reduces the number of trees present in an area
species diversity may be reduced
reduces animal species as destroys their habitat
agriculture affecting biodiversity
deforestation
removal of hedgerows
use of chemicals such as pesticides
herbicides
monoculture
climate change affecting biodiversity
melting of the polar ice caps could lead to the extinction of the species living in these regions
aesthetic reasons for maintaining biodiversity
enriching lives, inspiration for artists, recovery from stress or injury
economic reasons for maintaining biodiversity
medical uses
soil erosion and desertification due to deforestation
tourism
cross breeding
ecological reasons for maintaining biodiversity
interdependence of species, keystone sprecies, maintaining genetic resources
conservation
protecting and preserving natural resourcesand the environment
in situ conservation
conservation methods wuthin the natural habitat
ex situ conservation
conservation methods within the natural habitat
wildlife reserve
an area of land where wild animals live and are protected
controlled grazing
only allowing animals to graze land for a certain periof of time, giving species time to recover
seed banks
institutions that preserve seed types as a kind of living museum of genetic diversity
reasons why organisms in captivity cannot be released
- diseases
- behaviour
- genetic races
- habitat
how might genetic biodiversity be affected by a seed bank
- small sample sizes may reduce genetic biodiversity
- reduce size of gene pool
- removed natural interbreeding
- surviving population more vulnerable to disease
