chapter 11- biodiversity Flashcards
definition of biodiversity
biological variety of living organisms in an area at a particular time.
biodiversity changes over time
biodiversity is a measure of….
variation at the genetics, species and habitat level
define habitat biodiversity
the number of different habitats found in a particular area
usually the greater HB the greater the SB in that area
Define the term “species biodiversity”.
the number of species and their evenness/abundance in a particular area or ecosystem
differences in species, this can be structural and functional
Define the term “genetic biodiversity”
the diversity of alleles and number of genes in the genome/genetic material of species or a population of species
the greater the GB the greater chance of adapting….
to selection pressures and survival of a species
without genetic diversity organisms wont be able to …… and give egs
adapt to changes/threats in their habitat
eg climate change
pollution
disease
pest
What three human activities are the main factors currently affecting biodiversity?
climate change
agriculture
population growth
What are the three main reasons for maintaining biodiversity?
aesthetic
economical
ecological
where is biodiversity
usually greater
it is greater nearer the equator which is the result of the warm climate and high primary productivity
terrestrial means
on earth
what is a community
all the populations living in a particular geographical area at the same time
what is a population
the number of all the organisms of the same species who live in a particular geographical area at the same time
what is a habitat
the environment in which a particular organism/species lives
organisms can adapt to their habitat depending on
biotic and abiotic factors
what is the ecological importance of maintaining biodiversity
it maintains a balanced ecosystem by providing energy and nutrient cycles
what is the economical importance for maintaining biodiversity
potential useful species eg medicine, food, clothing, foods and agricultural
what is the ethical importance for maintaining biodiversity
potential medicines available
what are the two methods for measuring species diversity
species richness
species evenness
what is species richness
the number of different species in an area
what is species evenness
a comparison of the size of each population in an area
the greater the species richness and evenness in an area the
higher the biodiversity
the bigger the sample the more
accurate the estimate
quadrats usually have 100 squares, what is rhe area of the quadrat
0.25m2
limitations of using a quadrat (2/3)
limited the low/flat surfaces
limited to plants and animals can run away
limitations of using a pit fall trap (2/3)
small invertebrates only
you need to be away of seasons and the time of day (hibernation and nocternal)
limitations of using the longworth mammal trap (2)
SIZE of animal
can only catch one at a timel
limitations of using sweep nets (2)
cant really be used randomly
skill is required with the net to be effective
limitation of dip net (1)
difficult to sample aquatic plants
limitations of pooters (3)
the diameter of the opening limits the size of the insect you can catch
limited by the height of the tree/ is it really random
insect could run away
limitations of remote cameras (1)
difficult to identify individuals/you dont know if youve seen them before
the animals are illusive