4.3 - Classification Flashcards
What humans have done to reduce biodiversity and therefore why we need to conserve species
We have caused a loss in biodiversity and extinction of some species by:
- hunting/over fishing
- killing pests which threaten our food supplies pollution
- deforestation/habitat destruction for land for buildings or farming land for just one crop species
- inadvertent introduction of new predators and competitors to native species
Reasons for conservation of plant and animal species
Ecological reasons
- habitat for other organisms (plants)
- part of food chain in ecosystem
- native species
- population may be nationally significant in maintaining existence in country
- maintain biodiversity
Economic reasons
- wood used for e.g. furniture making (trees)
- could be a tourist attraction (animal or plant species)
- could be a source of medicine or scientific research (plants)
Aesthetic reasons
- people enjoy looking at them (particularly plants)
Ethical reasons
- we have a moral responsibility to protect species as they have a right to an existence
Consequences of global climate change on biodiversity
- Species with narrow gene pools e.g. selectively bred domesticated plant and animal species lack the genetic variation necessary to cope with changes in the environment e.g. increasing temperatures and rainfalls caused by climate change
- If species can’t evolve, they will need to migrate or they will become extinct
Change in patterns of agriculture
- Farmers will need to grow different crops as old crops will no longer thrive in new climatic conditions. This could mean a reduction in yield or inability to meet demands of consumers.
- Land may be lost due to rising sea levels which will mean loss in farming land
- Warmer temperatures may mean longer growing seasons which mean higher yield
- Warmer temperatures means more evaporation and so more precipitation could be good in areas which normally experience drought as it may boost crop yield but it could cause flooding a loss of yield in other areas.
- Rising carbon dioxide levels and higher temperatures could increase rate of
photosynthesis and so increased crop yields
Change in patterns of disease
- new crops being grown in new areas (due to climate change) will encounter diseases that they have never been exposed to before - they will have no resistance to them
- longer growing seasons = more time for pests to breed = lower yields
- diseases will migrate - e.g. diseases confined to warmer climates may spread to Europe e.g. Anopheles mosquito carrying malaria parasite
Benefits of maintaining biodiversity of animal and plant species for agriculture
- Source of food
- Source of genetic variation for selectively breeding domestic populations with populations which have beneficial qualities e.g. to breed in disease resistance, quicker growth
- Source of natural predators to pests (reduce need for chemical pesticides)
- Source of natural pollinators for crops e.g. bees
In situ conservation
Advantages
- Conserving species in their natural habitat
- Conditions and food etc that they require for survival already present – cheaper than ex situ
- Species are already well adapted to living in habitat
- No special provisions need to be made
- Can create protected reserves
- Can ensure sustainable use of environment including land and resources o Allows for scientific research of ecosystem etc
- Permanently protects biodiversity in area and whole ecosystems
- Creates areas of interest for eco tourists
Disadvantages
- There may be threats to the survival of the species in this area
- e.g. predation, hunting
- Human activity could threaten species in wild e.g. hunting deforestation
- Disease could threaten survival of species
- Species could be outcompeted by other species
Measures to help preserve species in wild
- Ban hunting
- Create protected reserves
- provide breeding sites
- prevent habitat destruction
- monitoring of species e.g. with tagging
- feeding programmes
- educate tourists on not feeding wild animals and not dropping litter etc
- promotion of ecotourism to generate money to help with preservation
- in case the population falls again , create sperm and egg banks
Ex situ conservation of animals
Advantages
- health of individuals can be monitored and treated for disease to ensure survival
- young can be hand reared which reduces mortality of young
- provision of mates for breeding can be manipulated
- protection from hunting and predation
- competition reduced between individuals
Disadvantages
- Expensive
- Often animals don’t breed successfully due to
- captive stress
- they experience altered breeding cycles
- don’t have a compatible mate
- Space is limited
- limiting the number of individuals kept which limits the genetic diversity o lack of genetic variation which could lead to inbreeding
- Can be difficult to reintroduce species to the wild as
- the animals may become too tame and not be afraid of humans
- may be unable to reintegrate into the wild population
- may have difficulties finding food for themselves
- may face predation
- habitats may have been destroyed
Setting up captive breeding programmes
- collect animals form several sites (and keep in several different locations)
*different geographical locations will show geographical variation – maintains this geographical variation
*increases genetic variation
*reduce risk of inbreeding
*less risk of losing all individuals due to disease - try to minimise stress during capture
- zoos have a database of related individuals
- exchange of animals between zoos or exchange sperm from sperm banks as a
source of genetic material - artificially inseminate individuals
- this increases the number of animals available to avoid inbreeding
Botanical Gardens - Importance of seed banks
- to maintain genetic diversity
- to maintain plants for future or currently unknown uses
- to counteract extinction or prevent inbreeding
Problems with seed banks
- collection of wild seeds may disturb environment
- collected samples may not be representative of genetic diversity of species
- seeds from one area may not survive in different area
- seeds stored for a long time may not stay viable
- Asexually bred plants will have no genetic variation – reducing biodiversity
Advantages of using seed bank rather than adult plants to conserve endangered plant species
- most plants produce an excess
- so can be collected from wild without damaging wild population
- take up little space
- able to store large numbers
- easy and cheap to transport
- remaining viable for long periods
- less susceptible to disease / pests
How seeds are kept viable in seed banks
- ensure that seeds are germinated from time to time
- ensure new seeds are produced
- freeze seeds
How genetic variation is ensured in seed banks
- ensure you have many seeds
- collect seeds from many areas
- ensure the seeds have a mixture of genotypes
Aims for Convention on Trade in Endangered Species (CITES)
- conservation of biodiversity
- regulate and prevent trade in endangered species
- ensure trade does not endanger wild populations
- prohibit commercial trade in wild plants
- allow trade in artificially propagated plants
- allow some trade in less endangered plants and animals
How CITES helps to save endangered species
- countries in agreement make it illegal to poach species
- place ban on trade of endangered species
- increase cooperation between countries
- increase awareness of impact of illegal trade
