Biodiversity Module 4 Flashcards
What’s biodiversity?
The variety of living organisms in an area
What’s a species?
A group of similar organisms that are able to reproduce to give fertile offspring
What’s a habitat?
The area inhabited by a species, it includes physical factors and biotic factors
What’s habitat diversity?
The number of different habitats in an area
What’s species diversity?
The number of different species (species richness), and the abundance of each species (species evenness) in an area)
What’s genetic diversity?
The variation of alleles within a species
Generic formula for samipling to measure biodiversity?
Choose an area to study
Count the number of individuals of each species
Repeat
Use the result to estimate the total number of individuals, or the total number of species
What sampling technique would you use for plants, fly insects, ground insects, aquatic animals?
Plants = quadrats
Flying insects = sweep net
Ground insects = pitfall trap
Aquatic animals = net
How can you make your sample random?
Choose where to sample within the area, by dividing the area into a grid and using a random number generator to choose the coordinates
What are the 3 types of non-random sample?
Systematic
Opportunistic
Stratified
Describe systematic sampling?
When samples are taken at fixed intervals along a transect (line)
Describe opportunistic sampling?
When the samples are chosen by the investigator
Describe stratified sampling?
When different areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole
The greater the species richness and species evenness, in an area, the higher the?
Biodiversity
What’s species richness?
The number of different species in an area
What’s species evenness?
A measure of the relative abundance of each species in an area, the more similar the population size of each species, the greater the species eveness
Formula for Biodiversity?
D = 1 - (Sum of all the different species (Total number of individuals of that species/total number of organisms of all species)^2)
So will be adding up a value from each species
What range of values can the biodiversity be and what does this mean in terms of species richness and eveness?
Will be a value between 0 and 1, the closer to 1 the value is the more biodiverse it is, and therefore has higher species richness and eveness
What can low genetic diversity mean for a species?
The might not be able to adapt to a change in the environment, causing the whole population to be wiped out by a single event
Which type of populations may have low genetic diversity?
Isolated populations eg. animals in captivity
What are alleles?
Different versions of genes
Where are alleles of the same gene found?
At the same point (locus), on a chromosome
What does polymorphism describe?
A locus that has 2 or more alleles
Formula for giving a measure of genetic diversity?
Proportion of polymorphic gene loci = (Number of polymorphic gene loci / total number of loci) x 100 for a %
So you get the percentage of genes in the sample that have alleles
4 ways human population growth is reducing biodiversity?
Habitat loss
Over exploitation of resources
Urbanisation
Pollution
3 ways how the increased use of monoculture in agriculture is decreasing biodiversity?
Habitats are lost as land is cleared for farming
Local and naturally occurring plants and animals are seen as weeds and pests and so are killed
Very few types of crops are planted
How does climate change affect biodiversity?
Change in climate may mean a previous inhabitable area becomes habitable, or vice versa, so could increase or decrease the biodiversity
Can cause migration so biodiversity decreases in the place they leave, and increases in the place they migrate to
There may be nowhere for a species to migrate to, can cause extinction, decrease in biodiversity
What’s a keystone species, and why do we need to protect them and other species for biodiversity?
Keystone species, are species that the ecosystem depends on, and without them the ecyosystem would change dramatically (predators, modifiers, hosts)
Disruption of food chains, or nutrient cycles
Need to protect other species to maintain genetic resources, eg. new medicines
Why does continuous monoculture cause soil depletion?
Monoculture = growing a single variety of a single crop
So continuous monoculture invloves planting the same crop over and over again, so all the nutrients required for that plant are used up
Apart from ecological and economic reasons, why else should we maintain biodiversity?
Aesthetic reasons
What’s in situ conservation?
On site conservation, so protecting species in their natural habitat
Advantages and disadvantages of in situ conservation?
Both the species and the habitat is conserved
Larger populations can be protected, and and it’s less disruptive than Ex situ
Can be difficult to control some of the factors that are threatening a species
What is ex situ conservation?
Off site conservation, involves protecting a species, by removing part of the population from a threatened habitat and placing it in a new location
Advantages and disadvantages of ex situ conservation?
Can protect individual animals in a controlled environment, can be used to reintroduce species
Only a small amount of individuals can be cared for, expensive to recreate habitat, many species can’t breed in the conditions
What does the Rio convention on biological diversity aim to do?
Develop international strategies on the conservation of biodiversity, and how to use animal and plant resources in a sustainable way
Made it international law that conserving bio diversity is everyone’s responsibility
Provides guidance to governments on how to conserve biodiversity
What are the aims of the CITES (convention on international trade in endangered species?
Regulates international trade on wild animals
Made it illegal to kill endangered animals
Helps to conserve species by limiting trade through licensing, and making it illegal to trade in products from endangered animals
Raises awareness of threats to biodiversity through education
What does the countryside stewardship scheme aim to do?
Conserve wild life and biodiversity by improving habitats
Would pay landowners to follow their management techniques on how to manage land in the best way for habitats
