M4, C11 Biodiversity Flashcards
define biodiversity
a measure of the variety of different organisms in a specific area
what are the measures of sampling
number of organisms
distribution of organisms
measurable characteristics
what are the 3 non random techniques of sampling
opportunistic - sample that is most conveniently available
stratified - put organisms into subgroups and random sample taken from each
systematic - identify different areas then sample separately
what is the difference between line and belt transects
line transect is one line with quadrats placed at intervals whereas belt transects are two parallel lines and you take an area between the two line
what are the similarities between line and belt transects
see the distribution of organisms over a period time
quadrats placed at regular intervals
what are point quadrats
frame containing horizontal bar
at set intervals along the bar, long pins can be pushed into the ground
each species the pin touches is recorded
what are frame quadrats
square frame divided into a grid of equal sections
the type and number of species within each section is recorded
why is biodiversity important
maintains a balanced ecosystem
needed for food, oxygen, materials
every species relies on one another
what are the different levels of biodiversity
habitat - number of different habitats in an area
species - richness and evenness
genetic - the variety of genes that makes up a species
what are the two components of species biodiversity
species richness - number of different species in an area
species evenness - comparison of the numbers of individuals of each species living in a community
what is genetic biodiversity
variety of genes that makes up a species
eg. humans have around 25,000 genes but some plants have 400,000
what type of sampling is line and belt transects
systematic sampling
why is sampling not always reliable
could be bias because you chose the area with the most flowers or it looks interesting
by chance the area you picked might not be representative of the whole population
what are some ways to sample animals
pooter - catches small insects by sucking on a tube which brings smaller insects into a container
sweep nets - insects in long grass
pitfall traps - small crawling invertebrates captured in a hole in the ground which has a roof so it doesn’t fill with rainwater
tree beating - invertebrates living in trees captured in a white cloth a the bottom of the tree that is shaken or beaten
kick sampling - organisms in a river, substrate is disturbed and a net captures organisms which move into the flowing water
what are the 3 ways of using quadrats
density of plants - used for large plants so you count the actual number in a quadrat
frequency - used for species that are hard to count, like grass so you count how many squares the species is in to get a percentage
percentage cover - estimate by eye - quick and gives an estimate of abundance
define species richness
measure of the number of different species living in a specific area
define species evenness
how close in numbers the populations of each species in an environment are
how do you estimate animal population size
capture-mark-release-recapture technique
the greater the number of marked individuals recaptured, the smaller the population
what are abiotic factors
non-living conditions in a habitat
they have a direct effect on organisms
eg. light and water
for each abiotic factor, give the sensor used and the unit
a) wind speed
b) light intensity
c) relative humidity
d) pH
e) temperature
f) oxygen content in water
wind speed - anemometer, ms^-1
light intensity - light meter, lx
relative humidity - humidity sensor, mgdm^-3
pH - pH probe, pH
temp - temperature probe, degrees C
O2 content in water - dissolved oxygen probe, mgdm^-3
what are the advantages of using sensors when measuring abiotic factors
rapid changes can be detected
human error reduced
high degree of precision can be achieved
data can be stored and tracked on a computer
what area would be considered less diverse
an area that is dominated by only one or two species
what is simpson’s diversity index
what’s the calculation
calculates biodiversity
D = 1 - E(n/N)^2
D = simpsons diversity index n = total number of organisms in 1 species N = total number of all organisms E = the sum of (couldn't put in correct symbol)
what do the results of the simpsons diversity index show
0 = no diversity 1 = infinite diversity
how does the number of successful species differ in a low biodiversity and a high biodiversity
there are relatively few successful species in a low biodiversity
there are large number of successful species in a high biodiversity
how does the nature of the environment differ in a low or high biodiversity
low biodiversity - extreme conditions with relatively few ecological niches
high biodiversity - not stressful with more ecological niches
how does the adaptation of species differ in a low and high biodiversity
low biodiversity - relatively few species often with very specific adaptations
high biodiversity - many species with few specific adaptations
how do the type of food webs differ in a low and high biodiversity
low - simple food webs
high - complex food webs
how does the effect of a change in environment differ between low and high biodiversity
low - major effects on ecosystem
high - often a relatively small effect
what are alleles
what do more alleles mean
different versions of genes
the more alleles present in a population means the more biodiverse it is
why is genetic biodiversity useful
give an example
useful for the survival of the species
the more diverse means the higher the likelihood that some members will be able to survive new selection pressures
eg. the peppered moth
what factors increase genetic biodiversity
mutations - new alleles caused
interbreeding between populations/ gene flow - new alleles from other populations
what factors decrease genetic biodiversity
selective breeding captive breeding programmes rare breeds artificial cloning natural selection genetic bottlenecks founder effect genetic drift
how do you quantify genetic biodiversity
measure polymorphism
a polymorphic gene has more than one allele
a monomorphic gene has a single allele
the higher the proportion of polymorphic gene loci, the higher the genetic biodiversity of a population
what is locus or loci
the position of a gene on the chromosome
there are 10 loci in total and 4 were polymorphic
what is the proportion of polymorphic gene loci
4/10 X 100
= 40%
how do you calculate the proportion of polymorphic gene loci
Number of polymorphic genes / total number of loci
what are gel electrophoresis
what does it mean if you have a smaller fragment
if the loci has one band what does it mean
Restriction Enzymes cut DNA into smaller pieces
The pieces are placed into a gel
Positive and Negative electrodes are placed on either end of the gel
The negatively charged DNA travels toward the positive electrode
The smaller the fragment, the further it travels across the gel
A banding pattern is produced, which can be used to compare different loci between individuals
If a loci has one band it is monomorphic, if it has more it is polymorphic
why has the human population increased so quickly
improvements in medicine, hygiene, housing and infrastructure
so people live longer
what are the affects of an increasing population
more space is needed for housing, industry and farming
humans are disrupting the ecology of many areas
more deforestation, agriculture and climate change
how could deforestation naturally occur
forest fires caused by lightning or extreme heat and dry weather
acid rain also but that is caused by humans through pollutants
how does deforestation affect biodiversity in animals
destroys habitats
destroys food sources for animals
so number of animals decrease
animals could also be forced to migrate to other areas so biodiversity increases in a certain area
how does deforestation affect biodiversity in plants
directly reduces the number of trees
if only one tree is destroyed, species diversity is reduced
eg. rosewood is often cut down but this reduces useable trees
how does agriculture reduce biodiversity in animals
deforestation and removal of hedgerows creates land to cultivate but this reduces habitats for animals and destroys their food source
pesticides kills insects or animals that eat the crops but this directly kills a species and destroys a food source
herbicides also directly destroy the food source of weeds
monoculture - only one crop is grown and lots of species can’t live amongst only one plant
how does agriculture reduce biodiversity in plants
deforestation to get land directly removes trees
removal of hedgerows destroys plant species
herbicides kills weeds - plant diversity directly reduces
monoculture - only one plant grown
what were some key findings in the 2007 IPCC about climate change
The warming trend over the past 50 yrs is twice of that of the last 100 yrs
Water vapour in the atmosphere has increased
The ocean has absorbed 80% more heat causing the sea level to rise
The arctic temps have doubled in the last 100 years
Long-term upward trend of precipitation
why do some people not think climate change is caused by humans
the earth’s climate has shown fluctuations throughout history
how does co2 lead to climate change
traps thermal energy in the atmosphere
how does global warming/ climate change affect biodiversity
melting of ice caps leads to extinction of species. animals have to migrate to find habitats so more diversity in the north
rising sea levels flood low-lying land which destroys species. saltwater also flows further up rivers reducing fresh water for plants and animals
Higher temps and less rainfall mean species can’t survive meaning xerophytes become more dominant. this means food sources are lost
insect life cycles will change as they do things according to climate, which means some plants could be left out in pollination
tropical diseases could spread more easily killing off species
what are the aesthetic reasons to maintain biodiversity
presence of different plants and animals enriches our lives
natural world provides inspiration for musicians and writers
studies show patients recover quicker from stress or injury in a natural environment around plants
what are the economic reasons to maintain biodiversity - 8 reasons
- deforestation can cause soil erosion meaning we can’t grow crops so rely on other nations
- if resources are removed then industry could collapse
- biodiversity loss means that species can become extinct before they are discovered which could have been important for medicines
- monoculture leads to soil depletion which reduces soil nutrients and makes ecosystem more fragile so farmers will rely on expensive fertilisers to maintain productivity
- biodiversity provides protection against extreme weather and diseases so if we don’t maintain it then disease could wipe out crops eg. Irish potato famine
- areas with biodiversity attract tourists
- greater the biodiversity, the higher the potential to make products in the future
- more species means more cross breeding in plants which could lead to more resources
what are the ecological reasons to maintain biodiversity
- if you remove a species, a food source could be lost, food chains are destroyed
- eg. if bee numbers lower, less plants are pollinated meaning biodiversity decreases
- keystone species are essential for ecosystems because they have disproportionately large effect on their environment relative to their abundance
- maintain genetic resources so we can get food, drink, clothing, drugs and fuels
explain how sea stars, alligators and prairie dogs are keystone species
sea stars - they limit the population of urchins and mussels by eating them. it means there isn’t a domination of one species in the ecosystem so biodiversity remains high
alligators - make burrows for nesting. when they abandon it, it fills with fresh water which other animals use for breeding and drinking
prairie dogs - extensive tunnelling system which other animals can use. they are also a food source. soil remains healthy from the tunnelling which spreads nutrients which keeps plant life biodiverse
define conservation
the preservation and careful management of the environment and of natural resources
species and genetic diversity can be safeguarded
what are the two main categories of conservation and define them
in situ conservation - within the natural habitat
ex situ conservation - out of the natural habitat
in conservation how are species classified
extinct
extinct in the wild
endangered
vulnerable
what is sustainable development
economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs
in wildlife reserves, what are active management techniques
- controlled grazing
- restricting human access
- controlling poaching eg. removing rhino horns
- feeding animals
- reintroduction of species
- culling or removing invasive species
- halting succession (so habitats don’t turn back to woodland or become overgrown)
define succession
a natural process in which early colonising species are replaced overtime until a stable mature population is achieved
what is the purpose of marine conservation zones
to create areas of refuge within which populations can build up and repopulate adjacent areas
they prevent fishermen visiting because non-sustainable fishing methods can be devastating
what are the advantages of in situ conservation
species and habitats are conserved species have resources its adapted to species continue to evolve more space bigger breeding population cheaper than ex situ
what are the disadvantages of in situ conservation
difficult to control illegal exploitation eg. poaching :(
difficult to control environment and predators
how do botanical gardens maintain biodiversity
what are their limitations
plants are managed and provided with the correct nutrients, water and pests are removed
90% of plants aren’t conserved and these could be potential sources of genes which are resistant to disease or pests
what is a seed bank
what is its limitation
seeds are dried and stored at temps of -20 degrees to maintain their viability
provides a back up against the extinction of plants
some seeds die when they’re dried which is mainly tropical rainforest trees
what are captive breeding programmes
produce offspring of species in a human-controlld environment
often run and managed in zoos or aquatic centres
their aim is to create a stable, healthy population of a species and gradually introduce the species into the wild
maintaining genetic diversity is difficult
why can’t some organisms born in captivity be released in the wild? (4)
- they might have lost resistance to local diseases
- some of their behaviour is natural but some they are taught in the wild eg. they can’t learn to hunt as well in captivity
- the genetic make up of captive animals can become different from the original population meaning they can’t interbreed
- there might not be a big enough habitat for them to fit into, if there are already too many animals in one place it will cause tension and stress
what is the international union for the conservation of nature (IUCN)
it secures agreements between nations
once a year they publish a list of the conservation status of species which countries can then work together for
they also established CITES which regulates trade of plant and animal specimens
what is the rio convention
1992 - meeting between 172 nations
aka the earth summit
Agreements made were:
-countries had to develop national strategies for sustainable development
-take steps to stabilise greenhouse gas concentrations
-prevent the transformation of fertile land into desert and reduce effects of drought
what is the countryside stewardship scheme
offered government payments to farmers and land managers to enhance and conserve English landscape
aims were:
-sustain beauty and diversity
-improve, extend and create wildlife habitats
-restore neglected land
improve opportunities for countryside enjoyments
now been replaced by Environmental Stewardship Scheme
What are the pros of ex situ conservation
Controlled environment (predation easily managed)
Reintroduction of species
What are the disadvantages of ex situ conservation
Only small number of organisms cared for
Difficult and expensive to create right environment
Difficult in adopting to new location/environment
Captivity breeding isn’t very successful
