Biodiversity

Front 1

What is biodiversity?

Back 1

A measure of the variation found in the living world.

Front 2

What is habitat diversity?

Back 2

The range of habitats in which different species live.

Front 3

What's the difference between species richness and species evenness?

Back 3

Species richness is the no. of species whereas species evenness is the degree to which the species are represented.

Front 4

What is genetic diversity?

Back 4

Variation between individuals in the same species.

Front 5

What does sampling a habitat involve and how can this represent an entire population?

Back 5

You select a small portion and study it carefully. You then multiply up the numbers of individuals of each species in order to estimate the number in the whole habitat.

Front 6

Advantages and disadvantages of random sampling?

Back 6

It ensures that data isn't biased. However, it may not cover all areas equally and some species with a low presence may be missed.

Front 7

What is opportunistic sampling?

Back 7

It's when sampling decisions are made based on prior knowledge or during data collection. May deliberately sample an area that he knows contains a particular species.

Front 8

Advantages and disadvantages of opportunistic sampling?

Back 8

It's quick and easy. However, it may lead to bias as the researcher is drawn to a particular species and so could lead to an overestimate.

Front 9

What is stratified sampling?

Back 9

Dividing a habitat into its different areas and sampling this separately.

Front 10

Advantages and disadvantages of stratified sampling?

Back 10

Ensures all different areas are sampled and species aren't under represented. However, could lead to an over representation of some areas in the sample.

Front 11

What is systematic sampling?

Back 11

Sampling a habitat at fixed intervals across the habitat e.g. line and belt transects.

Front 12

Advantages and disadvantages of systematic sampling?

Back 12

This is useful when the habitat shows a clear gradient in an environmental factor e.g. getting drier. Only records species on the line and so some could be missed and this could lead to an under estimate of the biodiversity.

Front 13

Preparation for sampling a habitat is key- what kind of things need to be considered?

Back 13

Suitable clothing and footwear, apparatus needed for sampling, pens and paper, appropriate keys to identify plants and a camera to record specimens and grid location.

Front 14

What to consider when at the site?

Back 14

Important to realise that a range of sampling techniques can be used e.g. combining random and systematic sampling. Also consider the effect you will have on the habitat.

Front 15

Ways of working out percentage confer when using random quadrats?

Back 15

Estimate percentage cover, some quadrate have a grid so it's divided into smaller squares. Measure percentage cover with a point frame. A frame has a number of needles, lower it onto the quadrate and record the plants touching the needles.

Front 16

Difference between a continuous and interrupted belt transect?

Back 16

Interrupted is when you use a quadrat at set intervals along the line. Continuous is when you place the quadrat beside the line and move it alone the line to study a belt in detail.

Front 17

How has DNA sequencing been used by scientists to sample animals?

Back 17

DNA sequencing can be used to distinguish between droppings from different individuals, providing a more accurate way to calculate the population size.

Front 18

How does a pitfall trap work?

Back 18

The trap is a small container buried in soil so that its rim is below the surface. Animals moving along will fall into the container. Trap should contain some water or scrunched paper to prevent animals crawling out.

Front 19

How does a Tullgren funnel work?

Back 19

Place leaf litter in a funnel, a light above the funnel drives the animals downwards. They fall through a mesh screen and are collected in a jar underneath.

Front 20

How does a light trap work?

Back 20

Used to collect flying insects at night- Uv light attracts insects and they fall into a collecting vessel containing alcohol.

Front 21

Other methods to trap insects?

Back 21

A sweeping net to collect animals in low vegetation where it's not too woody. To collect from trees, spread a white sheet under the branch and knock it with a stout stick.

Front 22

Outline method for mark and recapture?

Back 22

1. Capture a sample of animals.

2. Mark each individual, no. captured is C1.

3. Release marked animals and leave traps.

4. No. captured on second occasion is C2 and the no. of already marked animals re-captured is C3.

total population=(c1 x c2)/c3

Front 23

Trap used to trap small mammals?

Back 23

Longworth trap

Front 24

What effect has human population growth had?

Back 24

Learnt to use the environment to our advantage, altered ecosystems to provide our food, destroy and fragment habitats, use the earth's resources and pollute the atmosphere.

Front 25

What affect does agriculture have on the environment?

Back 25

Clearing natural vegetation reduces the size of habitats and population size of wild species. This reduces genetic diversity so that the species is less able to adapt to changes and the population can become isolated and fragmented.

Front 26

What is a monoculture and what affect does this have?

Back 26

A monoculture is a crop consisting of one strain of one species. It limits the genetic diversity, a process known as genetic erosion.

Front 27

What factors affect biodiversity?

Back 27

Human population growth, agriculture, extinction and climate change.

Front 28

What happens as the climate changes?

Back 28

Species are less able to adapt to changes in the environment as they've lost their genetic diversity and so show less variation between individuals. This leads to migration.

Front 29

What obstructs migration?

Back 29

Human developments, agricultural land, large bodies of water and mountain ranges.

Front 30

What is a keystone species?

Back 30

One that has a disproportionate effect upon its environment relative to its abundance.

Front 31

What processes do natural ecosystems perform that are valuable to humans?

(economic reasons to maintain biodiversity)

Back 31

Regulation of atmosphere and climate, purification of fresh water, formation and fertilisation of soil, recycling of nutrients and waste, crop pollination, growth of timber, food and duel and discovery of molecules with potential as medicine.

Front 32

Aesthetic reasons to maintain biodiversity?

Back 32

Pleasing natural environments cause patients to recover more rapidly from stress and injury. Diverse tropical forests protect the soil from climatic factors. Woodland acts as a reservoir when it rains.

Front 33

Ecological reasons to maintain biodiversity?

Back 33

Organisms in a habitat are linked via a food chain. When one species is affected, this affects another. Habitats with higher species diversity are more stable. Helps maintain natural solutions to some of our problems e.g. wild animals and plants hold the answers to problems caused by climate change.