Human Impact on Biodiversity

Question 1

What does biodiversity reflect?

Answer 1

The number of species in an area and how evenly distributed the numbers of living org are spread across the range of species present

Question 2

What is the effect of agricultural intensification?

Answer 2

Large reduction in biodiversity

Question 3

What are the disadv of monoculture?

Answer 3

Reduced biodiv
Build up of pest spec to crop being grown
Growing same crop yr after yr on same land can lead to red of particular minerals in the soil b/c each successive crop has had the same mineral ion req
Crop is harv b4 decay/ decomposition can take place and return minerals to the soil

Question 4

What are the disadv of nutr enrichment of soils:

Answer 4

High levels of nitrate encourage fast growth of particular crop, is harmful to biodiversity, it allows the target crop to outcompete and eliminate many other slower growing species
Can also lead to loss of soil crumb str, which can lead to increases soil erosion

Question 5

What are the disav of the loss of hedgerows?

Answer 5

Leads to loss of biodiversity- through loss of habitat and food for many hedgerow species. This impacts on other species higher up the food chain
Loss of wildlife corridors. Hedgerows act as wildlife corridors linking areas of woodland or other species-rich habitats. Animals such as small mammals, birds, insects i.e butterflies use these for movement from place to place
Soil erosion can take place due to land being more exposed to wind and rain and the reduction of the soil binding role of tree and shrub roots

Question 6

What is a pest?

Answer 6

Is a species that damages a valuable/ commercial crop species causing economic damage

Question 7

Descr affect of broad spectrum pesticides:

Answer 7

(Insecticides) can reduce biodiversity by killing organisms of species other than the intended target. Kill soil organisms that are involved in decomp and improving soil str

Question 8

What can pesticides do in terms of predators?

Answer 8

Can eliminate natural predators of the main pest and cause pest resurgence allowing the pest to return in greater numbers

Question 9

How do herbicides reduce biodiversity?

Answer 9

This type of pesticide used to kill weeds/ competitor plant species) reduces biodiversity (kills non-crop species) and reduces the variety of food avail to a variety of animal species

Question 10

What happens when species become resistant to pesticides?

Answer 10

There can be issues with bioaccumulation (build up of conc in the tissues of organisms at higher trophic levels)

Question 11

What is polyculture?

Answer 11

Growing of a range of different crops at the one time or sequentially in the one place

Question 12

What are the adv of polyculture?

Answer 12

Wider range of food sources and habitats for wildlife, leading to more/ complex food webs
Crop rotation is the planting of different crops in the same field over a period of yrs. This helps conserve soil fertility as the different crops make different demands on soil nutrients
Crop rotation can improve soil fertility when N-fixing crops (peas, beans, clover) are part of the cycle
Crop rotation reduces the likelihood of a build-up of pests specific to one in an area

Question 13

What are the adv of increased use of organic fertilisers?

Answer 13

Helps preserve soil crumb str as the humus in the farmyard manure holds the crumb str together
Farmyard manure releases nutrients at a slower rate with less mineral loss due to leaching, as the plant can make better use of the more slowly released nutrient

Question 14

What are the disadv of increased use of organic fertilisers?

Answer 14

More difficult to spread and store
Nutrient content is more variable

Question 15

How does biodiversity friendly hedgerow trimming will further increase biodiversity?

Answer 15

Allowing hedgerows trees to grow to maturity at intervals in the hedge
Only trimming on a 2-3 yr rotation. This allows shrubs to flower and produce berries (providing food for birds over the winter months)
Trimming during late winter ( Jan-Feb) to avoid the destr of birds nests during the spring and summer and allowing berries to dev in the autumn
Maintaining a range of hedge heights and widths by staggering trimming regimes. Different bird species have different pref for hedgerow heights and widths.
Hedges cut in a A shape as opposed to a box shape can be particularly diverse as this allows more light, to penetrate to the ground level

Question 16

How does protecting newly planted hedge/ repairing an existing one increase biodiversity?

Answer 16

A double fence can be placed around the hedge, this both protects the young hedge and forms an effective boundary in the interim. Once the hedge is established/ repaired the fence is removed

Question 17

How does integrated pest management and biological control increase biodiversity?

Answer 17

May kill target pests but also eliminate the natural predators of the pest and kill soil organisms important in the decomp of organic matter and the maintenance of soil fertility

Question 18

How do narrow spectrum pesticides increase biodiversity?

Answer 18

Only affect the target pest species have now ben introduced

Question 19

How does crop rotation increase biodiversity?

Answer 19

Helps prevent the build-up of large pest populations as the absence of a specific crop for a few yrs may prevent the pest being able to complete its life cycle.

Question 20

Biological Control

Answer 20

Involves deliberately introducing predator species that target the pest. This is an alternative to using chemical pesticides.

Question 21

What are the adv of effective biological control?

Answer 21

No chem damage to the env/ bioaccumulation in the food chain
Biological control targets only the pest species
The dev of res by the pest is unlikely
Pest resurgence unlikely
Needs little additional action and saves money on the continued use of pesticides

Question 22

What are the limitations of biological control?

Answer 22

Pest will not be totally eliminated- its density is reduced (to below the level for economic damage)
Biological control will only work if the biological control species can adapt and thrive in the ecosystem into which it is introduced

Question 23

How do predator strips increase biodiversity?

Answer 23

Small areas of rough grass left undistributed at field hedges will encourage the increase in numbers of many crop pests natural predators on the farmland- ladybirds can thrive in relatively species-rich predator strips- undisturbed thru the absence of fertiliser or pesticides) and feed on the harmful aphids that damage the crops

Question 24

What are the main ways that waterways are polluted?

Answer 24

Urbanisation
Industrial Waste
Poor Sanitation Levels
Agriculture

Question 25

State the process of organic pollution:

Answer 25

1: Organic Pollution provides a rich source of nutrients
2: Aerobic bact inv in the decay process uses these nutrients as a food source
3: This causes a population explosion of the aerobic bacteria
4: The bacteria uses up the O2 in the water due to aerobic resp

Question 26

How do bact have a high BOD?

Answer 26

High BOD leads to a decrease in the O2 level in the water. BOD is an ind of water qual.
A high BOD indicates pollution, a low BOD indicates no pollution.
High BOD reduces diversity as few org can live in low O2 levels

Question 27

What is eutrophication?

Answer 27

Gradual long-term nutrient ( Inorganic) enrichment of water ways, in particularly nitrates and phosphates

Question 28

Where does nutrient enrichment come from?

Answer 28

Comes from the use of artifical fertilisers. If too much applied/ applied on slopping ground close to rivers/ wet cond then eut will occur.

Question 29

State the 7 steps of eutrophication:

Answer 29

1: Nitrates and phosphates leach thru the soils into the water
2: Increased nitrates and phosphates in the water lead to an increase in algal growth (algal blooms)
3: Algal blooms prevent light penetrating thru the water
4: The plants at lower levels die due to a shortage of light
5: Dead plants are decomposed, by aerobic bacteria (Increasing BOD)
6: The bact uses up all the O2 in aerobic resp
7: The shortage of O2 results in the death of many species of invertebrates and fish. This reduces biodiversity.

Question 30

State 6 strategies to reduce eutrophication:

Answer 30

1: Testing the ion content of soil and ensure that only the correct conc of req ions are added so that supply does not exceed demand in the target crop
2: Only apply artificial fertiliser immediately prior to or during periods of plant growth
3: Do not apply a.f when heavy rain is forecast
4: Do not apply a.f close to water bodies
5: Ensure there are adequate storage facilities
6: Follow governmental guidelines :
DARD NI code of Good Agricultural Practice for the prev of pollution of water
European Nitrates Directive Action Programme

Question 31

Descr ASSI

Answer 31

Ecological imp areas that have high conservation value. These are managed in coop with landowner in a way to promote biodiv

Question 32

Descr SACs

Answer 32

These areas have a special protective status, to conserve threatened species and habitat

Question 33

Descr Biodiverisity Action Plan:

Answer 33

Inv policies and activities organized at a local council level. They inc local initiatives, activities ( e.g promoting hedgerows), making leaflets promoting biodiversity along with other conservation groups

Question 34

Descr DAERA

Answer 34

Provides financial and other support to farmers, with the aim to promote biodiversity, conservation of rare habitats, improve water quality and removal of harmful weeds and invasive plants

Question 35

Descr NI priority habitat and species list:

Answer 35

Id habitats and species for conserv and protection of species. List can be used by council planning offices. Habitats on the list may include blanket bogs and estuaries. Species on the list inc the corncrake and frog orchid

Question 36

How does increased comb of ff
and deforestation contrib to cc and global warming?

Answer 36

1: Increased comb of ff has added CO2 to the atmosphere
2: Deforestation: reduced the amount of phs and conseq less CO2 is removed from the atmosphere

Question 37

How does CO2 and other gh gases cause global warming?

Answer 37

Form a layer in the atmosphere that traps heat. Shorter wave radiation can reach the Earth’s surface. However, some of the longer wave radiation from the Earth’s surface cannot pass thru the atmosphere and is trapped and reflected and retained in the atmosphere. This is reflected and retained heat results in atmsop temp rising.

Question 38

Descr melting of ice caps

Answer 38

Rate of shrinking of ice caps is increasing as the ice is getting thinner. This melting causes water to be released into the oceans.

Question 39

Descr and explain what melting of ice caps causes:

Answer 39

Raising sea levels: impact lowland countries and some Pacific islands and habitats lost
Disruption of ocean currents: Britain would be adversely effected if the Gulf Stream bringing warmer water across the Atlantic was pushed north. Higher global temp will also make the oceans expand further increasing sea levels

Question 40

Descr and explain changing climates:

Answer 40

Summers in Britain become wetter, Warmer ocean hurricanes occur more frequently and become stronger

Question 41

How could distrib of many plants and animal species change as temp changes?

Answer 41

Loss of some species and introd of others e.g introd of hear requiring mosquito and malaria parasite

Question 42

How does climate change effect biodiversity?

Answer 42

G.W can lead to desertification in warmer areas. Deserts have low biodiversity b/c few org can tol extreme env. Flooded area, less biod and food web effected- reduces species biodiversity if one species in food web extinct. Warmer climates also increase the rate of disease spread