BIODIVERSITY Flashcards
biodiversity
variety of organisms living in an area
species
group of similar organisms able to reproduce and give fertile offspring
habitat
an area inhabited by a species
includes abiotic factors- soil and temperature
biotic factors- food availability and presence of predators
habitat diversity
number of different habitats in an area
species diversity
number of different species in an area
genetic diversity
variation of alleles within a species
sampling techniques
plants- quadrant
flying insects- sweep net
ground insects- pitfall trap
aquatic- net
non random sampling
systematic- samples taken at fixed intervals along a transect
opportunistic- samples chosen by investigator
stratified- different areas are identified and sampled separately in proportion to their part of the habitat as a whole
species richness
number of different species in an area
species evenness
measure of relative abundance of each species in an area
allele
different versions of a gene
genetic polymorphism
polymorphism- a locus that has 2 or more alleles
alleles of the same gene are found at the same locus on a chromosome
working out the proportion of polymorphic gene loci in an organism gives a measure for genetic diversity
proportion of polymorphic gene loci
number of polymorphic gene loci
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total number of loci
human population growth
habitat loss
over exploitation- greater demand for resources resulting in resources being replenished
urbanisation- sprawling cities and major city developments can isolate species meaning they can’t interbreed which lowers genetic diversity
pollution- kills species and destroys habitats
increased use of monoculture in agriculture
habitats lost and land is cleared
local and naturally occurring plants killed with pesticides and herbicides
heritage varieties of crops are lost because they don’t make enough money and so aren’t planted
climate change
areas become inhabitable/habitable
increase/decrease in range of some species
some migrate- changes species distribution
can’t migrate fast enough leads to extinction
protect keystone species
if one species is lost it causes a disruption in the food chains and disruption of nutrient cycles
keystone species- species that other species depends upon
maintain genetic resources
food, clothing, drugs, fuels
important to the global economy
allows us to adapt to changes in the environment
economic reasons for maintaining biodiversity
reduce soil depletion
monoculture- growing a single variety of a single crop will result in soil depletion
increased spending on fertilisers and decreased yields
aesthetic reasons for maintaining biodiversity
attractive landscapes are protected
more aesthetic- more visitors- more economical advantages
in situ conservation
on site conservation
involves protecting species in their natural habitat
ensures survival of endangered species
methods of in-situ conservation
establishing areas as national parks and wildlife reserves which restrict urban development, industrial development and farming
controlling or preventing the introduction of a species that threatens local biodiversity
protecting habitats
promoting particular species
giving legal protection to endangered species
advantages of in-situ conservation
both species and their habitats are conserved
larger populations can be protected and it’s less disruptive than removing organisms from their habitat
chances of population recovering are greater than with ex situ methods
disadvantage of in-situ conservation
difficult to control some factors that are threatening a species e.g poaching, predators, disease and climate change