B6.1 - Monitering & Maintaining The Environment Flashcards
Sampling
Taking observations & measurements from a small area, representative of a larger area to estimate
Apparatus & techniques to collect living animals:
- Pooters
- Sweep nets
- kick sampling
- tree beating
- pitfall traps
Pooters
- suck on mouthpiece to draw insects into holding chamber
- filter stops organisms entering mouth
Sweep nets
sweep large net through air to catch flying insects / insects in long grass
Kick sampling
- ‘kick’ river bank/bed to disturb mud/vegetation
- hold net downstream to capture organisms released into flowing water
Tree beating
- stretch large white cloth under tree/bush
- shake/beat tree to dislodge invertebrates, will fall into cloth
Pitfall traps
- dig hole in ground
- crawling invertebrates (beetles, spiders, slugs) will fall into
- cover hole with roof so trap doesn’t fill with rain water
Types of identification keys (to identify living organisms)
- branched key: answer yes/no for each question
- numbered key: correct answer to a question tells you which question to answer next
Capture-recapture technique
- Capture organisms from sample area
- Mark individual organisms, then release back into community
- At later date, recapture organisms in original sample area
- Record number of marked & unmarked individuals
- Estimate population size
Estimated population size equation (capture-recapture technique)
Estimated population size = (first sample size x seconds sample size) / no. of recaptured marked individuals
Quadrat, how do you sample plants
Square frame divided into a grid
- place it onto ground to take sample & record type & no. of organisms within each section
- take multiple samples & calculate mean average for accurate results
Random sampling
- position of sample not pre-determined
- individuals selected by chance
- prevents bias
Eg. Number generator to give random coordinates
Non random sampling
- systematically choosing where to take a sample
- transect: samples taken along line, place quadrat at fixed positions along line
Eg. To see how plant species change as move inland from sea
Why is biodiversity important
- species interconnected, so removal of 1 species can affect others
- essential for maintaining balanced ecosystem
- humans rely on biodiversity for raw materials (food, wood, oxygen)
How is biodiversity lost
increased need for food & materials due to increased population causes:
- deforestation
- agriculture
- hunting & fishing
- pollution
Deforestation
- removing forest provides wood for building/fuel & creates space for roads/buildings/agriculture
- reduces no. of trees & no. of supported animal species as food source & home lost, can also affect predator species
Agriculture
Many intensive farming techniques(for increased population):
- remove hedgerows to use large machinery & extra land for crops: reduces no. of plant species & destroys habitat of animals (mice/hedgehogs)
- pesticides to kill pests that eat crops/live on livestock: removes food source (pests) of other organisms, can ruin food chain, killing animals not targeted
- herbicides to kill plants growing where not wanted: reduces no. of plant species present & no. of animal species present (removes food/shelter)
Fishing
- overfishing = some fish populations decrease significantly/extinct in some area
- other marine species may be caught/killed
Hunting
- decreases target species population, removes food for other species (ruins food chain)
- allow unchecked growth of some plant species, outcompete other plants
Pollution
generally, more polluted area = fewer no. of species that can survive
Techniques to prevent biodiversity loss
- conservation
- seed banks
- captive/selective breeding
Conservation techniques
- controlled grazing (only allow animals to graze land for certain period of time, plant species have time to recover)
- restricting human access (providing paths, prevent plants being trampled)
- feeding animals (ensure organisms survive to reproductive age)
- reintroduction of species (adding new individuals of species to area where numbers decreases significantly / species haven’t survived)
Captive breeding
- breeding animals in human-controlled environments (zoo/aquarium)
- animals given shelter, nutritious food, veterinary treatment, predator-free environment
- suitable breeding partners imported from other zoos
Aim of captive breeding
- create stable, healthy population of species
- gradually reintroduce species back into its natural habitat
Problems with captive breeding
- maintaining genetic diversity difficult since few breeding partners available
- organisms born in captivity not suitable to release into wild (predators may not know how to hunt, prey how to survive)
Seed banks
- way of conserving plants to prevent extinction
- seeds carefully stored so new plants may be grown in future
- gene bank (store of genetic material)
Eg. Millennium Seed Bank Project at Kew Gardens, large underground frozen vaults preserve billions of seeds
International agreements to maintain biodiversity
- IUCN
- CITES
- Rio Conventions
IUCN
= International Union for the Conservation of Nature
- publishes the ‘Red list’ which details current conservation status of threatened animals
- countries work together to conserve these species
CITES
= Convention on International Trade in Endangered Species of Wild Fauna and Flora
- regulates international trade of wild plants & animals & their products to prevent over-exploitation
- protects more than 35,000 species
Rio Conventions
- require countries to develop strategies for sustainable development
- to reduce greenhouse emissions & combat desertification
- aim to maintain biodiversity, but countries not forced to implement them
Local agreements to maintain biodiversity
Stewardship Schemes:
- farmers in England offered government payments to conserve landscape
- aim to make conservation part of normal farming practices
Ecotourism
Form of tourism that minimises the impact of visitors on he environment
Indicator species
Organisms that can be used to measure environmental quality
Their presence/absence tell biologists if an area is polluted
Sulfur dioxide
- released from combustion of some fossil fuels
- causes acid rain, can result in death of trees/fish
What indicator species is used to measure sulfur dioxide air pollution
LICHENS
- no root systems, most nutrients come from air
- rainwater contains enough nutrients to keep them alive
- acid rain can damage lichens & prevent their growth
- some species can cope with high levels of pollutions, other grow in clear air
- lack of lichens sign of high pollution
Water pollution
- caused by discharge of harmful substances into rivers, lakes, seas
- higher level pollution = lower level of dissolved oxygen
- indicator species used to indicate oxygen content in water as some enquire higher oxygen content than others
Indicator species to monitor water pollution
Unpolluted = mayfly larva
Low pollution = freshwater shrimp
High pollution = water louse
Very high pollution = sludgeworm
