Chapter 11 Biodiversity

Question 1

Definition of Biodiversity

Answer 1

the variety of living organisms present in an area. It includes plants, animals, fungi, and other living things. In fact everything from gigantic redwood trees to single-celled algae.

Question 2

The importance of biodiversity

Answer 2

it is essential in maintaining a balanced ecosystem for all organisms. All species are interconnected - they depend on one another. In regions of reduced biodiversity, dependence may not not all be present, which eventually harms all species in the ecosystem.

Question 3

Measuring biodiversity

Answer 3

Biodiversity is greatest at areas around the equator and least at north/south poles.
By measuring biodiversity you are able to judge the effects major projects.

Question 4

Habitat biodiversity

Answer 4

refers to the number of different habitats found within an area. The greater the habitat biodiversity, the greater the species biodiversity. UK has high habitat biodiversity whereas Antarctica is low.

Question 5

Species biodiversity

Answer 5

includes:
species richness - the number of different species living in a particular area,
species evenness - a comparison of the numbers of individuals of each species living in a community.

Question 6

Genetic biodiversity

Answer 6

refers to the variety of genes that make up a species.
genetic biodiversity within a species can lead to different characteristics being exhibited. Some genes are the same for the organism but some genes are different based on type of organism.
Greater genetic biodiversity within a species allows for better adaptation to a changing environment, and is more likely to result in individuals who are resistant to disease.

Question 7

Why is sampling used

Answer 7

it is impossible to count all of the organisms present in an area, so sampling techniques are used.

Question 8

What is sampling

Answer 8

sampling means taking measurements of a limited number of individual organisms present in a particular area. It can be used to estimate the number of organisms in an area without having to count them all. Sampling can be used to measure a particular characteristic.
After sampling you can use the results of a sample to make generalisations or estimates.
There is random and non-random sampling

Question 9

Random sampling

Answer 9

means selecting individuals by chance. Each individual has an equal chance of being selected. You can use a random number generator.

Question 10

Non-random sampling - 3 types

Answer 10

Opportunistic - uses organisms that are conveniently available.
Stratified - Population divided into a number of groups. Random sample then taken from each proportional to its size
Systematic - Different areas are sampled separately. Uses a line transect and belt transect can be used to do this

Question 11

Reliability

Answer 11

Sampling bias - the selection process may be biased. This may be by accident or deliberate. The effects of sampling bias can be reduced using random sampling, where humans involvement in choosing sampling is reduced.
Chance - the organisms may be selected by chance, not representative of the whole population. Chance can never be removed.

Question 12

What is a pooter

Answer 12

It is used to catch small insects. By sucking on a mouthpiece, insects are drawn into the holding chamber via the inlet tube. A filter before the mouthpiece prevents them from being sucked into the mouth.

Question 13

Sweep net

Answer 13

are used to catch insects in areas of long grass.

Question 14

Pitfall traps

Answer 14

are used to catch small, crawling invertebrates such as beetles, spiders and slugs. A hole is dug in the ground, which insects fall into. It must be deep enough that they cannot crawl out and covered with a roof-structure propped above so that the trap does not fill with rainwater. The traps are usually left overnight, so tat nocturnal species are also sampled.

Question 15

Tree beating

Answer 15

is used to take samples of invertebrates living in a tree or bush. A large hite cloth is stretched out under the tree. The tree is shaken or beaten to dislodge the invertebrates. The animals will fall onto the sheet where they can be collected and studied.

Question 16

Kick sampling

Answer 16

is used to study the organisms living in a river. The river bank and bed is kicked for a period of time to disturb the substrate. A net is held just downstream for a set period of time in order to capture any organisms released into the flowing water.

Question 17

Point quadrat

Answer 17

this is made of a frame with a horizontal bar. At set intervals along the bar, long pins can be pushed through the bar to reach the ground. Each species of plant the pin touches is recorded.

Question 18

Frame quadrat

Answer 18

this consists of a square frame divided into a grid of equal sections. The type and number of species within each section of the quadrat is recorded. To collect a representative sample of an area, quadrats should be used following a random sampling technique. To study how the presence and distribution or organisms across an area of land varies, the quadrat can be place systematically along a line or belt transect.

Question 19

Measuring species richness

Answer 19

Many sampling techniques should be used to try to identify all the species present in a habitat. A list should be compiled of each species identified. The total number of species can then be calculated.

Question 20

What are the three ways of sampling the population of plants using frame quadrats

Answer 20

Density - if individual large plants can be seen clearly, count the number of them in a 1m by 1m square quadrat. This will give you the density per square metre. This is an absolute measure, not an estimate

Frequency - this is used where individual members of a species are hard to count. You count how many of the small grids the species is in. Then you form a percentage of the grid covered by the organism.

Percentage cover - it is an estimation of the area by eye of how much is covered. it is used for speed

Question 21

How to estimate the population size of an animal

Answer 21

Capture - mark - release - recapture technique
First capture as many of the species in an area as possible. The organisms are then marked and tagged. Then release to organisms. Then after some time recapture the organisms. This time compare the number of tagged organisms to non-tagged. The greater the number of marked individuals recaptured, the smaller the population.

Question 22

Measuring abiotic factors

Answer 22

these are the non-living factors
wind speed - anemometer - m/s
light intensity - light meter - lx
relative humidity - humidity sensor - mg/dm^3
pH - pH probe - pH
temperature - themometer - C
oxygen content in water - dissolved oxygen probe - mg/dm^3

Question 23

How to calculate biodiversity

Answer 23

Simplest way - count up the number of species present - the species richness.

Simpsons Index of Diversity ( D) takes into account both species richness and species evenness.
D = 1 - Sigma(the total number of organisms of a particular species/ the total number of organisms of all species)^2.

1 represents infinite diversity, whereas 0 represents no diversity.
The higher the value the more diverse the habitat.

Question 24

The importance of genetic biodiversity

Answer 24

of some genes species have different versions called alleles. This creates genetic biodiversity within the species. The more alleles present the more genetically bio diverse the population. With greater biodiversity, species are more likely to be able to adapt to changes in their environment because there is more likelihood of organisms within the population that carry an advantageous allele which enables them to survive in altered conditions.

Question 25

How can genetic biodiversity increase

Answer 25

mutations in the DNA or an organism, creating a new allele. interbreeding between different population. Gene flow

Question 26

How can genetic biodiversity decrease

Answer 26

selective breeding - where only a few individuals within a population are selected for their advantageous characteristics and bred. Captive breeding - endangered populations are bred to increase populations Artificial cloning - a sexual reproduction, using cuttings to clone a farmed plant. Natural selection - as a result, species will have the advantageous charecteristics. This causes less and less alleles to be existant. Genetic bottlenecks - where a few individuals within a population survive an event or change - reducing the gene pool. Only the alleles of the surviving members are available. Founder effect - where a small number of individuals create a new colony. The gene pool for this new population is small. Genetic drift - due to the random natural of alleles being passed on from parents to their offspring, the frequency of occurrence of an allele will vary, potentially causing the existance of a particular allele can disappear.

Question 27

Polymorphic and monomorphic genes

Answer 27

Polymorphic genes have more than one allele for each gene whereas monomorphic genes has one allele for each gene. You can calculate the proportion of polymorphic genes using the formula number of polymorphic gene loci/ total number of loci. The loci refers to the position of the gene on a chromosome. The greater the proportion of a polymorphic gene loci, the greater the genetic biodiversity within the population.

Question 28

How does deforestation influence biodiversity

Answer 28

Deforestation can be natural through forest fires, lightning or extreme heat but is mostly caused by humans. Some is indirect e.g. acid rain caused by pollutants of humans. Deforestation reduces the number of trees if only a specific type of tree is felled, the species diversity is reduced. deforestation reduces the number of animals species present in an area as it destroys their habitat. Animals are forced to migrate to other areas to ensure their survival. This increases biodiversity of neighbouring areas to increase.

Question 29

How does agriculture influence biodiversity

Answer 29

Farmers will only grow a few different species of crop which reduces biodiversity. To make more profit farmers will: - deforestation - to increase the area of land available for growing crops or rearing animals. - removal of hedgerows - farmers removes hedges to allow large machines to help them. The destroys habitats and reduces the number of plant species in the area. Use of chemicals such as pesticides and herbicides. - Pesticides are used to kill pests that would eat the crops or live on the animals. The reduces species diversity. Herbicides - reduces plant diversity , animal diversity as well - because a food source is reduced. Monoculture - many farms produce 1 crop. This lowers biodiversity since there is only one crop.

Question 30

How does climate change influence biodiversity

Answer 30

If global warming continues biodiversity will be affected. Fo example: - the melting of the polar ice caps could lead to extinction of plants and animals in the region. - rising sea levels from melting ice caps and the thermal expansion of oceans could flood low - lying land. - higher temps and less rainfall would result in some species dying out, and xerophytes surviving.

Question 31

Aesthetic reasons for maintaining biodiversity - 3 reasons

Answer 31

- The presence of different plants and animals in our environment enriches our lives. - The natural world provides inspiration for people such as musicians and writes. - Studies have shown patients recover more rapidly from stress and injury when they are supported by plants and a relatively natural environment.

Question 32

Economics reasons for maintaining biodiversity - 6 reasons

Answer 32

- Soil erosion and desertification may occur and it will reduce the country's ability to grow crops and feed its people. - Conserving all organisms that we use to make things is essential. Once all of the raw material has been lost, it does not become economically viable to continue the industry. - Species may be lost before they are even discovered with large scale habitat losses. - Continuous monoculture results in soil depletion. - When biodiversity is not maintained, a change in a condition or a disease can destroy entire crops. - High biodiverse areas can provide tourism in the region.

Question 33

Ecological reasons for maintaining biodiversity

Answer 33

- All organisms are interdependant on eachother - the removal of one species may have a significant effect on others, for example a food source or a place to live may be lost. - some species play a key role in maintaining the structure of an ecological community. These are known as keystone species. When a keystone species is removed it has drastic impacts on the ecosystem.

Question 34

Human activity vs Biodiversity

Answer 34

Humans have created biodiversity in some areas e.g. farming, grazing, planting of hedges, meadows and forest management have changed landscapes.

Question 35

Definition of conservation

Answer 35

the preservation and careful management of the environment and of natural resources. By conserving natural habitat in an area, organisms chances of survival are maintained, allowing them to reproduce.

Question 36

Two categories of conservation

Answer 36

in situ - within the natural habitat ex situ - out of the natural habitat

Question 37

4 classifications of species

Answer 37

extinct - no organism of the species exist anywhere in the world extinct in the wild - organisms of the species only exist in captivity endangered - a species that is in dange of extinction vulnerable - a species that is considered likely to become endangered in the near future.

Question 38

Definition of sustainable development

Answer 38

economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs.

Question 39

What is in situ conservation?

Answer 39

takes place inside an organism's natural habitat. This maintains normal conditions of genetic diversity etc. It preserves interdependent relationships present in a habitat.

Question 40

Wildlife reserves

Answer 40

the is active management - controlled grazing - allowing livestock to graze a specific area - restricting human access - - controlling poaching - creating defences to prevent access. - feeding animals - ensures more organisms survive - reintroduction of species - adding species to areas that have become locally extinct - culling or removal of invasive species - halting succession - early colonising species are replaced over time until a stable mature population is achieved.

Question 41

Marine conservation zones

Answer 41

Marine reserves preserve species rich areas such as coral reefs. Marine reserves create areas of refuge where populations can build up and repopulate adjacent areas.

Question 42

What is ex situ conservation?

Answer 42

involves the removal or organisms from their natural habitat.

Question 43

Botanic gardens

Answer 43

Here plant species are actively managed to provide them with the best resources to grow, such as the provision of soil nutrients, sufficient watering, and the removal or prevention of pests. 35000 plant species are held in 1500 botanic gardens worldwide. this is only 10% of species

Question 44

Seed banks

Answer 44

It is a store of genetic material for plants. Seeds are dried and stored at -20C. This provides back up against the extinction of wild plants. The Svalbar in Norway stores seeds of 800000 species. It will eventually have 3 million different types of seeds and aims to provide a back-up against the extinction of plants in the wild. Seed banks don't work for all plants.

Question 45

Captive breeding programmes

Answer 45

These produce offspring of species in a human-controlled environment. These are often run and managed zoos and aquatic centres. e.g. The national marine aquarium in SW england does this for seahorse species. Several species are now solely represented by animals in captivity. Scientists working on these programs aim to create a stable, healthy population of a species, and then reintroduce the species back. Programs provide shleter, food, an absense of predators and veterinary treatment, partners. Mating can be organised to maintain genetic diversity.

Question 46

Why will some organisms born in captivity not be suitable for release in the wild.

Answer 46

Disease - there is a loss of resistance to local disease in captive-bred populations. Also there may be new diseaese to which resistance isn't developed. Behaviour - Some behaviours such as searching food haven't been learnt Genetic races - the genetic make up of captive animals can become so different from the original populations that the two populations cannot interbreed. Habitat - in many cases the natural habitat must first be restored to allow captive populations to be reintroduced.

Question 47

What are conservation agreements?

Answer 47

To conserve biodiversity successfully, local and international cooperation is require to ensure habitats and individual species are preserved. Animals do not respect a country's boundaries. Therefore, to increase the chances of a species survival, cross border protections should be offered.

Question 48

International union for the conservation of nature

Answer 48

IUCN assist in securing agreements between nations. They publish a red list, detailing the current conservation status of threatened animals. Countries then work together to conserve these species. IUCN was also involved in the establishment of CITES - Convention of International Trade in Endangered species. This treaty regulate the international trade of wild plant and animals specimens and their products. As the trade in wild animals and plants crosses borders, the effort to regulate requires international cooperation. 35000 species of animals and plants are protected now.

Question 49

The Rio Convention

Answer 49

In 1992, a historic meeting of 172 nations was held in Rio de Janiero, which became known as the Earth Summit. The summit resulted in some new agreements between nations in the Rio Convention: - The convention on Biological Diversity require countries to develop national strategies for sustainable development, thus ensuring the maintenance of biodiversity. - The UN framework convention on Climate Changes (UNFCCC) is an agreement between nations to take steps to stabilise greenhouse gas concentrations within the atmosphere. - The UN Convention to combat desertification (UNCCD) aims to prevent the transformation of fertile land into desert and reduce the effects of drought through programmes of international cooperation.

Question 50

Countryside Stewardship Scheme

Answer 50

Many conservation schemes were set up at a local level. An example is the countryside stewardship scheme in England. The scheme, which operated from 1991 - 2014, offered governmental payments to farmers and other land mangers to enhance and conserve the English Landscape. Its general aim was to make conservation a part of normal farming and land management practice. Specific aims of the scheme included: - sustaining the beauty and diversity of the landscape - improving, extending and creating wildlife habitats - restoring neglected land and conserving archaeological and historic features. - improving opportunities for countryside enjoyment. This schmee has now been replaced by the Environmental Stewardship Scheme, which operates similarly.