Biodiversity Flashcards
Biodiversity ?
Variety of living organisms in an area
Species ?
Group of similar organisms able to reproduce to give fertile offspring
Habitat?
Area inhabited by a species
- include abiotic and biotic factors
What levels can biodiversity be assessed ?
Habitat diversity - number of different habitats in area (sand dunes,woodland,meadows and streams)
Species diversity - no. Different species/abundacne of each species in area
Genetic diversity- variation of alleles within a species ( different breeds within species etc )
How can a sample to measure biodiversity be taken?
Choose area to sample
Count no. Individuals of each species
Repeat/take many samples for more REPRESENTATIVE RESULTS
Equipment used to take samples for different organisms?
PITFALL TRAP/POOTER - catch ground insects
TULLGREN FUNNEL- leaf litter/soil placed in funnel and light forces organisms to fall out funnel/be collected
KICK SAMPLING - kick bottom of the stream/use a net to collect organisms that have been disturbed
SWEEP NET - sweep net back and fry along grass to catch insects in grass
3 types of non random sample?
Systematic : samples taken at fixed intervals, often along a line (e.g quadrants placed at reg intervals, placed along transect )
Opportunistic: sample chosen by investigator
Stratified: different areas of habitat identified /sampled separately in proportion to their part of the habitat
What is species richness and species evenness ?
SPECIES RICHNESS : numbe of different species in an area
SPECIES EVENNESS : Measure of relative abundance of each species in an area
What is the Simpson’s Index of diversity ? Formula?
Takes into account SPECIES RICHNESS AND EVENNESS
- measures diversity
- closer to 1 the index is, the more diverse habitat is
D= 1 - (sum of (n/N)2 )
N= total no. Organisms of all species n= total number of individuals of one species
Importance of genetic diversity of a population?
- increased variation means :
more likely to have an adaptation that allows survival to environment changes
What is polymorphism ? How can we use genetic polymorphism to measure genetic diversity ?
Polymorphism - locus that has 2 or more alleles
Proportion of polymorphic gene loci = no. Polymorphic gene loci / total no. Loci
Factors effecting global biodiversity?
- Human population growth
- Increased use of monoculture in agriculture
- Climate change
How does human population growth affect biodiversity?
Habitat loss- decreases habitat diversity
Over exploitation - greater demand for resources means resources used up —> decrease genetic diversity /species diversity (from extinction e.g from overfishing)
Urbanisation- road development/cities isolate species , so populations can’t INTERBREED/genetic diversity is decreased
Pollution - pollutants kill species/destroy habitats
How does the increased use of monoculture affected biodiversity ?
Monoculture - growing of a single variety of crop
Due to this :
Loss of habitat - to clear land - reduce HABITAT DIVERSITY
Local/natural plants and animals destroyed with PESTICIDES/HERBICIDES —> reduce species diversity
Traditional crops lost - don’t make enough money so not planted anymore —> reduce species diversity
How has climate change affected biodiversity ?
- areas get colder/hotter/wetter or drier
Causes change in :
Species distribution - species may have to migrate (reduce biodiversity in place they came from)
Extinction - if species can’t migrate/nowhere to migrate /change is to fast , causes EXTINCTION
Disease - conditions are warmer, tropical disease can spread
Rising sea levels - more frequent floods- destory habitats on low lying land
Ecological reasons for maintaining biodiversity?
1. Protect species /KEYSTONE SPECIES
- organisms in ecosystem are interdependent so removal of one species DISRUPTS FOOD CHAINS /NUTRIENT CYCLES
KEYSTONE SPECIES - other species in ecosystem depend on keystone species - ecosystem change dramatically if not there e.g PREDATORS/MODIFIERS/HOSTS
Have significant effect on ecosystem
2. Maintain genetic resources
- materials from plants,animals, microoorganism that contain genes, that are valuable
Used for : food/drink, clothing, drugs, fuels, industrial materials
- genetic resources allow us to adapt to changes in environment - can use genes from plant to make drought resistant plants
Economic reason for maintaining biodiversity?
To reduce soil depletion
- caused by continuous monoculture - planting same crop in same field without interruption
Soil depletion causes INCREASED SPENDING ON FERTILISERS/DECREASE YEILDS - economic costs
Aesthetic reasons for maintain biodiversity?
- attractive landscapes due to biodiversity
- more tourism
What is In Situ conservation and methods of this?
On site conservation - conservation of species in their NATURAL HABITAT
Methods:
National parks/wildlife reserves - restricts urban/industrial development
Control/prevention** of species that threatens local biodiversity
**Protect habitats*
Promote particular species (by preaching food sources etc)
Legal protection to endangered species - illegal to kill them
Advantages/disadvantages of in situ conservation ?
Ad : Both species/habitat conserved
Larger populations protected
Less disruptive
Population recovery chances are higher
Dis : difficult to control some factors that are a threat to a species
What is ex situ conservation ? And methods to do this?
Off site conservation - move species from threatened habitat to new place
Methods :
Relocating to safer area
Breeding programs in captivity then put into wild when ready
Botanic gardens - controlled environs to grow rare plants for conservation/research
Seed banks - seeds frozen/stored in seed banks without losing fertility
- source of seeds if natural reserve destroyed
Advantages/disadvantages of ex situ conservation?
AD: - protect individual animals in controlled environments - predation/hunting controlled
- Can be used to Reintroduce a species that have left an area
DIS : used for small no. Induviduals
- difficult /expensive to sustain right environment
- less successful than IN SITU - species can’t breed in captivity /don’t adapt to new environment
Eg of international cooperations involved in species conservation?
RIO CONVENTION ON BIOLOGICAL DIVERSITY (CBD)
- aims to develop international strategies on conservation of biodiversity / use animal/plant resources in a sustainable way
- provide guidance to governments/made it a international law to conserve biodiversity
CITES agreement
- agreement to increase international cooperation in regulating trade in wild animals/plant specimens
- made it illegal to kill endangered species
- limits trade through licensing/illegal to trade products from endangered animals
Example of a Local conservation agreement?
Countryside stewardship scheme (CSS)
- to conserve wildlife /biodiversity and improve/extend wildlife habitats by promoting managment techniques to landowners
Offered 10 yr agreement to pay landowners who followed management techniques (e.g refer as hedgerows /leave grassy margins)
