chapter 11: Biodiversity Flashcards
what are the 3 ways of measuring biodiversity
habitat diversity
species diversity
genetic diversity
define habitat diversity
the number of different habitats in an area
eg. could include dunes, woodlands and streams
define species diversity
the number of species in an area (species richness)
the abundance of each species in an area (species evenness)
define genetic variation
the variation of alleles within a species (or population)
what are the ways of random sampling
random sampling - using quadrats, point quadrats, pitfall trap, kite net, pooter, tullgren funnel
what are the non-random ways of sampling
systematic, opportunistic, stratified
define species richness
the number of species found in a habitat
the more species present the richer the habitat
a simple count is not quantitative enough to give a measure of diversity as it does not count the number of individuals of each species
define species evenness
counts relative numbers of abundance
numbers of species per unit area (frequency)
what does simpsons diversity index measure
measures the diversity of a habitat, taking into account species richness and evenness
the higher the number the more diverse a habitat
a low value indicates low diversity - dominated by few species
define gene
a section of DNA that codes for a protein
define allele
an alternative version of a gene
define gene locus
the place on a chromosome where a gene is found
define monomorphic
only one version of a gene
define polymorphic
two or more versions of a gene (alleles)
how do you calculate the proportion of polymorphic gene loci
number of polymorphic gene loci /
total number of gene loci
what factors affect biodiversity
human population growth
agriculture (monoculture)
climate change
what are some reasons for maintaining biodiversity
ecological - protecting keystone species and maintaining genetic resources
economic - including soil depletion (continuous monoculture)
aesthetic - including protecting landscapes
define in situ conservation
attempting to conserve species in its natural environment
eg. protected areas such as national parks and nature reserves
define ex situ conservation
conserving species outside its normal environment
relocating to a safer place
eg. botanic gardens and breeding in captivity
what are the advantages and disadvantages of in situ conservation
advantages - maintains natural ecosystems and evolutionary processes
allows you to protect multiply species at once
cheaper / more cost effective
allows the animals to remain in their natural habitat
disadvantages - still vulnerable to habitat destruction and external threats - cannot be fully safe
what are the advantages and disadvantages of ex situ conservation
advantages - offers high level of protection from immediate threats
allows for research and breeding programmes
disadvantages - can be expensive to set up and maintain
may not replicate natural habitats well
animals may not adapt well to new environment
can only be suitable for small populations of species eg. zoos and seed banks
what is the convention on International Trade in Endangered Species (CITES)
regulate and monitor international trade
ensures international trade does not endanger the survival of wild populations
ensure that trade in wild plants is prohibited for commercial purposes
what is the Rio Convention on Biological Diversity
signed in 1992 by 150 countries
promotes sustainable development
what is the countryside stewardship scheme
local conservation agreement
introduced in 1991
paid land owners to manage land for biodiversity
eg. regenerate hedgerows
leave grassy margins for wildflowers
graze upland areas to reduce bracken
