B6.1 - Monitoring And Maintaining The Environment Flashcards
Sweep nets
Used to capture flying insects and others fury grass areas. A net with a large stick that you swing to catch
Pooters
A contraption, where you suck the insects in through a straw. They get trapped in a mesh, and drop into a container. Used for small insects such as ants
Kick sampling
When you face downstream holding a net. You lightly kick the water to dislodge the aquatic invertebrates from the river bed.
Ensure the strength, frequency and area of the kick is the dame
Tree beating
To collect insects which live in trees. You use a long stick which you use to hit the trees. This makes invertebrates fall out and you catch them in a large outstretched cloth
Pitfall traps
Captures small insects living on ground such as beetles, ants. Dig a hole into the ground, with a shallow slope (to make sure they don’t fall and die). Covered with a slight platform, to ensure other animals don’t see it, and to prevent rain (otherwise they drown) Leave slightly open at top to allow oxygen in for respiration.
How can u identify organisms
Use identification keys to compare
Equation for estimating population size
First sample x second sample / number of marked individuals
Capture recapture
Uses scaling up to estimate a population size
Limitations of capture recapture
Ensure you use the correct marking technique. E.g water proof mark on aquatic animals
Random sampling
Unbiased decisions about where to sample. This is more accurate
Non random sampling
E..g using a transect. Measuring at set distances
Importance of biodiversity
Needed for all organisms to survive, since all are linked and depend on each other
How can biodiversity be lost
Agriculture - intensive farming can reduce biodiversity in attempts to get high yield of good quality foods. Using pesticides and herbicides
Deforestation- removes tree which then ruins food sources, homes, shelters for animals. They are forced to move
Fishing - overfishing reduces biodiversity since not many fish survive.
Pollution - toxic for organisms and most die. Very few can remain in such conditions
Eutrophication
Surface run off or leeching through soil takes excess fertiliser into water bodies.
Fertiliser promotes growth of algae bloom, which not only block sunlight for lower plants, but also use up oxygen for respiration.
Algae at the bottom eventually dies from lack of sunlight for photosynthesis and lack of oxygen
Fish and other animals then die, due to lack of food, lack of oxygen
Algal bloom will then die, since not animals will provide CO2 for their photosyntheses
Conservation
Process of trying to protect natural habitats and environments to increase the chance of an organisms surviving
Examples of conservation
Seed banks
Selective breeding
Seed banks
Conserves plants
Seeds stored of varieties of plants, to preserve for future.
It is an example of a gene bank (storing genes)
Backup against extinction of plants
Captive breeding
Breeding animals in a human controlled environment such as a zoo or aquarium
Purpose of captive breedings
Create a stable population
Reintroducing the species to the natural habitat
Disadvantages of captive breeding
Marinating genetic diversity is hard, due to low number of individuals
Organisms born into captivity , may lose natural instinct, and hence be less likely to survive in the natural habitat - w.g. Predators not knowing how to hunt for food
Ecotourism
Allowing tourism, but in a way to ensure that the natural environment is not disturbed
How to get indication of pollution
Indicator species are organisms used to measure environmental quality . - by seeing the species that thrive in an area, you know how polluted it is.
