Chapter 9 - Natural ecosystems and human activities Flashcards
(122 cards)
1
Q
What is an ecosystem?
A
An ecosystem is all the living things (biotic components) together with all the non-living things (abiotic components) in an area.
2
Q
What is a population?
A
A population is all the organisms of one species living in a defined area.
3
Q
What is a community?
A
A community is a group of populations of different species that live together in an area and interact with each other.
4
Q
What is a habitat?
A
A habitat is the place within an ecosystem where an organism lives.
5
Q
What is a niche?
A
A niche is the role of a species within an ecosystem.
6
Q
What are biotic components?
A
Biotic is any living components of the environment that may affect other living things. E.g. producers, primary consumers, secondary consumers, tertiary consumers and decomposers.
7
Q
What are abiotic components?
A
Abiotic is any non-living components of the environment that may affect living things. E.g. temperature, humidity, water, oxygen, salinity, light and pH.
8
Q
What are the three biotic interactions?
A
The three biotic interactions are competition, predation and pollination.
9
Q
What is competition?
A
Competition occurs because living things need a range of resources from the environment. Many younger are produced that will survive, so there is often competition for resources. Individuals least adapted to the current conditions will die or fail to reproduce.
10
Q
What is predation?
A
Predation is when one animal eats another.
11
Q
What is pollination?
A
Pollination is the transfer of pollen grains (male gametes) from the anther to the stigma for it to fuse with the ovule (female gamete). Pollen grains can either be blown by wind or carried by insects.
12
Q
What is photosynthesis?
A
Photosynthesis is the process by which plants or plant like organisms make glucose in the form of carbohydrates from carbon dioxide and water using energy from sunlight. Carbon dioxide + water -> Glucose + oxygen. Plants trap light energy with the help of chlorophyll. It also splits water into hydrogen and oxygen.
13
Q
How plants obtain the different components required for photosynthesis?
A
Plants obtain carbon dioxide from the atmosphere through their stomata in the leaves and water from the soil through their roots.
14
Q
What is a food chain?
A
Food chain is a diagram showing the relationship between a single producer and primary, secondary and tertiary consumer. Food chains cannot have more than 4 or 5 trophic levels as there is not enough energy to pass on.
15
Q
What is a food web?
A
Food web is a diagram that shows the relationship between all or most of the producers, primary, secondary and tertiary consumers in an ecosystem.
16
Q
What is a trophic level?
A
Trophic level is a feeding level within a food chain or a food web.
17
Q
What is a pyramid of numbers?
A
Pyramid of numbers is a diagram that represents the number of organisms at each trophic level in an ecosystem by a horizontal bar whose length is proportional to the numbers at that level.
18
Q
What is a pyramid of energy?
A
Pyramid of energy shows the amount of energy at each trophic levels. It is always pyramid shaped. Only about 10% of energy is passed on to the next trophic level. The other energy is lost as heat, used for cellular respiration, growth, lost as faeces or lost by incomplete digestion by higher trophic levels.
19
Q
What is the carbon cycle?
A
The carbon cycle shows how moves between the atmosphere, soils, living creatures, the ocean, and human sources. carbon dioxide in the atmosphere, fixation by photosynthesis in plants, plants die, animals feed on plants, animals respire, animals die, carbon is present in organic chemicals in dead matter such as humus, the is fossilised to form fossil fuels, organic matter respires and decays, fossil duels are burned.
20
Q
What are seven advantages of wetlands?
A
Wetlands provide shoreline protection, maintenance of water quality, flood control, recharging of aquifers, biological productivity, provide habitats and are a source of a variety of products such as fish, fuel and fibres.
21
Q
How does the drainage of wetlands lead to habitat loss?
A
The causes of habitat loss include drainage of wetlands for agriculture, forestry, mosquito control, flood protection, use of disposal waste created by road construction, discharge of pollutants, peat removal and the removal of groundwater, intensive agricultural practices as overcultivation of soil leads to soil erosion, causing habitat loss for decomposers living in the soil and deforestation as the clearance of climax communities that would otherwise provide habitat for a wide range of tree and ground dwelling species.
22
Q
What are climax communities?
A
Climax communities are ecological communities in which populations of plants or animals remain stable and exist in balance with each other and their environment.
23
Q
How does habitat loss lead to extinction?
A
Impacts of habitat loss include extinction which is the process by which a species or other name group ceases to exist on earth or another named area, loss of biodiversity which occurs when various species die or relocate when their habitat is destroyed, genetic depletion which is the loss of species containing potentially useful genes.
24
Q
What are four causes of deforestation?
A
Causes of deforestation include timber extraction and logging for a range of luxury products or a source of energy, subsistence and commercial farming, roads and settlements and rock and mineral extraction.
25
What are five impacts of deforestation?
Impacts of deforestation include
habitat loss as biodiversity is lost when habitats are lost, soil erosion and desertification as forests reduce the impact of heavy rainfall on the ground which reduces soil erosion. Tree roots bind the soil in place and the layer of fallen leaves and branches protects the soil, overtime after deforestation the area that has once supported luxuriant growth may because a desert because of desertification, climate change as the permanent removal of trees leads to large quantities of carbon dioxide when burnt or decomposed and loss of biodiversity and genetic depletion as various species die or relocate when their habitat is destroyed leading to the loss of species containing potentially useful genes.
26
What are carbon sinks?
Carbon sinks are vegetated areas where the intake of carbon dioxide from the atmosphere in photosynthesis exceeds the output from respiration, so the net flow of carbon is from the atmosphere into plants. An example of these are growing forests.
27
What are carbon stores?
Carbon stores are mature vegetated areas where the intake of carbon dioxide from the atmosphere by photosynthesis equals its output from respiration so the mature plant stores carbon. An example of this is a mature forest.
28
What is the role of forests in the water cycle?
Role in the water cycle as forests add water to the atmosphere during transpiration, leading to the formation of clouds, eventually releasing it by precipitation. During deforestation, this process is reduced, and local droughts are caused in the area. Forest generate moisture in the atmosphere that can affect rainfall around the world.
29
What is the role of forests in preventing soil erosion?
Prevention of soil erosion as trees intercept rain, reducing heavy rainfall on the flood, debris such as tree leaves on the floor of the forest slows run off, roots of trees hold the soil in place and forests on the coast reduce soil erosion by absorbing energy from storms.
30
What is the role of forests for ecotourism?
Ecotourism is the responsible travel to a natural area that promotes conservation of the environment. Visitors travel with the main aim of appreciating its beauty. Ecotourism is both a reason to manage forests sustainably and a method by which this can be achieved, it may be mainly economic in focus, with success measured by income or focused on sustainability, with success measured by a limit on the number of visitors.
31
What is the role of forests for biodiversity as a genetic resource?
Biodiversity as a genetic resource as forests are vital for the lives of many animals, plants and other organisms because of the habitats they provide. These organisms in return represent a huge genetic resource as well as a source of food, medicine and raw materials for industry.
32
What are four ways to measure biodiversity in an ecosystem?
Pitfall traps, pooters, quadrats and transects
33
What are pitfall traps?
Pitfall traps are used to sample non-sedentary organisms such as insects. It consists of a jar sunk up to its rim in the soil, the jar may or may not be covered depending on the predicted likelihood of rainfall, traps should be inspected and emptied regularly, it can be used randomly or systematically, a drawback is that is measures the activity and number of the species.
34
What are pooters?
Pooters are sued to sample non-sedentary organisms such as insects. Insects in short vegetation or on trees are usually trapped in this net. For example, a pooter is used to transport the organisms from the nets or traps to a laboratory.
35
What are quadrats?
Quadrat is a frame of the known area placed on a part of the site to be samples. It is used to sample sedentary organisms such as plants. The number of organisms of the species is then counted, sometimes the percentage of the organisms in the quadrat is calculated.
36
What are transects?
Transect is a sampling method in which sampling devices are laid out along a line already placed across an area. It is used for sampling sedentary organisms such as plants and is an example of systematic sampling.
37
What are three advantages of quadrats?
Quick, inexpensive and portable
38
What are two disadvantages of quadrats?
Not always very accurate, unless many quadrats are placed the sample can be unintentionally biased
39
What are three advantages of transects?
Quick, inexpensive and portable
40
What is a disadvantage of transects?
Often used in inappropriate situations
41
What are two advantages of pitfall traps?
Inexpensive, easy set up and use
42
What are two disadvantages of pitfall traps?
Often kill the organism captured, may over sample or under sample
43
What is random sampling?
Random sampling is a sampling method in which the sampling device is placed using random tables or a dice role. It is used when two areas need to be compared.
44
What is systemic sampling?
Systematic sampling is a sampling method in which the sampling device is placed along a line or a predetermined pattern, usually a transect. It is used to check how the species change along a gradient in the environment.
45
What are twelve ways to manage biodiversity in an ecosystem?
Sustainable harvesting of wild plants and animal species, sustainably forestry, agroforestry, alley cropping, national parks, wildlife and ecological reserves, wildlife corridors, extractive reserves, world biosphere reserves, seed banks, zoos and captive breeding, and sustainable tourism and ecotourism.
46
What is sustainable harvesting of wild plant and animal species and how does it help to manage biodiversity in an ecosystem?
Sustainable harvesting of wild plant and animal species means to meet the needs of the present without denying the needs of future generations. Many plants have medicinal properties because of the secondary metabolites they produce which are organic compounds produced by bacteria, fungi or plants that are not directly involved in the normal growth, development or reproduction of the organisms. Wild plants are the preferred source as cultivated varieties only produce small or none of the chemicals used. Management plans to control the harvesting of wild-grown medicinal plants include assessing the abundance of the plant, investigating species growth rates, reproductive biology, impact of harvesting, assessing the yield that the wild population can sustain and details of how the harvesting should be monitored.
47
What is sustainable forestry and how does it help to manage biodiversity in an ecosystem?
Sustainably forestry is the removal of only mature trees of species that are valuable. Other species and immature trees of value species are left, allowing the forest to repair over. Non valued trees still provide habitat for many species and immature valued trees can be used years later.
48
What is agroforestry and how does it help to manage biodiversity in an ecosystem?
Agroforestry is a land management system in which crops are grown around trees. Trees enrich the soil when the leaves fall and provide food for animals, firewood for people and sometimes medicine. Tree roots bind the soil together and, in some cases, fix nitrogen, further enriching the soil. Farmer obtain food and milk from the farm, and their animals enrich the soil with manure.
49
What is alley cropping and how does it help to manage biodiversity in an ecosystem?
Alley cropping includes planting rows of trees at wide spacings with a companion crop grown in the alleyways between the rows. Trees are pruned, and the pruning’s are used to improve the soil and provide minerals to the crop, mineral recycling and the suppression of weeds by trees are combined with cropping on the same land, thereby allowing the long-term survival of farmland.
50
What are national parks and how does it help to manage biodiversity in an ecosystem?
National parks are areas of land protected by the government to preserve entire ecosystems. They have laws that ban or limit activities such as hunting, logging and collection of wildflowers, enforcement requires regular inspection and threat of hefty fines or imprisonment for breaking the law, extensive tourist facilities are provided, including roadways, carparks and natural trails, an entry fee is charged for conservation work, a guidebook or leaflet includes information on the dos and don’ts and the importance of the conservation of wild nature
51
What are wildlife and ecological reserves and how does it help to manage biodiversity in an ecosystem?
Wildlife and ecological reserves include the practice of protecting wild plant and animal species and their habitat that plays an important role in balancing the ecosystems and different natural processes.
52
What are wildlife corridors and how does it help to manage biodiversity in an ecosystem?
Wildlife corridors are links of wildlife habitats, generally native vegetation, which joins two or more larger areas of similar wildlife habitat. Corridors are critical for the maintenance of ecological processes including allowing for the movement of animals and the continuation of viable populations.
53
What are extractive reserves and how does it help to manage biodiversity in an ecosystem?
Extractive reserves is an area of land, generally state owned, where access and use rights, including natural resource extraction, are allocated to local groups or communities.
54
What are world biosphere reserves and how does it help to manage biodiversity in an ecosystem?
World biosphere reserves are ecosystems with plants and animals of unusual scientific and natural interest. The plan is to promote management, research and education in ecosystem conservation. The advantages include being recognised internationally and it attracts funding and support of experts in the conservation community, improving the success of the reserve.
55
What are seed banks and how does it help to manage biodiversity in an ecosystem?
Seed banks store seeds to preserve genetic diversity when it’s not possible to protect the area where the endangered plant lives. Wild plants carry genes that could be used in crop plants to confer resistance to pests and diseases, seeds occupy less space than plants thus more species can be held, collecting small samples of seeds is unlikely to damage the wild population as most plants produce a large number of seeds, seeds are dominant and need mineral care thus easier to store than living plants.
56
What are zoos and captive breeding programs and how does it help to manage biodiversity in an ecosystem?
Role of zoos and captive breeding provide education about the illegal trade in animals and products, and the need to maintain biodiversity. It is involved in scientific research on the control of diseases, animal behaviour and techniques to improve breeding success. Captive-breeding programs increase species numbers, thus reducing the risk of extinction, they aim to release captive-bred animals into the wild when habitats have been restored, they try to maintain the genetic biodiversity of a species, as interbreeding leads to a reduction in diversity and therefore reduces adaptability when the species is placed back in the wild.
57
What is sustainable tourism and ecotourism and how does it help to manage biodiversity in an ecosystem?
Sustainable tourism and ecotourism is the management of tourism in a sustainable way to prevent damage to habitat and provide what people want. The key to successful sustainable ecotourism is realising that the growth of the tourist industry depends on maintaining the environment. Measures are taken to safeguard wildlife, and the resources are used sustainably.
58
State why trees are a carbon sink (1)
trees take in / absorb carbon dioxide
59
Explain the benefits to tigers of connecting the two ecological reserves by a corridor (3)
Increased access to prey / water ;
free movement of prey ;
finding a mate / reproducing ;
reduced chance of extinction ;
maintain genetic diversity in the population / reduces inbreeding ;
reduced disturbance by humans / larger habitat / territory ;
gives a suitable habitat in the case of wildfires ;
60
Ecotourists visit the reserves to see the tigers. The ecotourists stay in houses in villages in the corridor. Suggest reasons why this type of ecotourism is a sustainable activity (2)
tourists have to live the same as local people / no hotels / accommodation built ;
limited damage to environment / small scale ;
local people can make money (so likely to help protect habitat/tigers) / helps fund conservation project ;
can go on for a long time / future generations can still do it ;
61
This diagram shows part of the carbon cycle. State the processes at A, B and C (3)
A – combustion:
B – respiration;
C – photosynthesis;
62
Explain how extractive reserves and seed banks reduce the threat of extinction (4)
Extractive reserves:
prevents development in the area;
only locals permitted to harvest in the area;
harvesting / use of trees is sustainable;
investment to maintain the security of the forest;
Seed Banks:
(wide range of) genetic material held;
stored until suitable conditions are available;
can be used in future plant breeding / increase genetic diversity;
safe storage in case wild population destroyed;
63
Describe the process of pollination (2)
the movement of pollen from an anther to a stigma ;
animal / insect / named insect pollination / wind pollination ;
64
Explain why algae are producers (2)
they produce their own glucose;
use process of photosynthesis / trap sunlight / convert light energy;
first trophic level;
65
Explain the difference between a food chain and a food web (1)
food chain only shows one feeding relationship / food webs show alternative sources of food for organisms or
consumers / food web is more than one food chain;
66
Describe how the scientist can randomly sample the Aral Sea (2)
use of, coordinates / grid (on a map);
(random) number generator (to identify sampling point);
67
Suggest two benefits of repeat sampling (2)
idea of impact of different, times / seasons / weather / climate;
results can be compared / identify a trend;
identifies, anomalous results or outliers;
improves, reliability / validity;
68
Explain how biosphere reserves conserve biodiversity (3)
prevent or limits hunting or poaching;
prevents or limits, mineral extraction / mining;
zoned / access restricted / controlled environment / protected area;
monitoring / allows for research / idea of scientists allowed in some areas;
raises awareness / education (of public);
treatment of diseases / medical support;
(eco)tourism / minimises impact of tourism;
69
State two processes in the carbon cycle that release carbon dioxide (2)
respiration;
combustion;
70
Explain why it is important for ecosystems to be managed sustainably (3)
available for future generations;
prevents extinction / preserves biodiversity / prevents genetic depletion;
prevents disruption of, food webs / chains;
prevents loss of habitats or stated example of habitat destruction e.g. deforestation / soil erosion;
reduce risk of relevant natural disaster e.g. flooding or mass movement or land slides / reduce impact of drought or crop diseases;
71
A scientist investigates the population of Spodoptera moths in a 1000m2 field of maize
using a random sampling technique.
Describe how the scientist:
* uses random sampling
* uses a quadrat
* records the data collected
* obtains an estimate for the population of Spodoptera moths in the field (4)
uses random sampling
grid the field / use GPS coordinates ;
use a stated method to randomly choose quadrat sites e.g. random number generator ;
uses a quadrat
count the number of moths in the quadrat ;
records the data collected
use of table / tally system ;
obtains an estimate
number of moths in a quadrat by area of field ;
72
Suggest two limitations of sampling Spodoptera moths using a quadrat (2)
fly or move ;
could be counted more than once ;
camouflaged / difficult to identify or see ;
hide during the day / only be active at night / nocturnal ;
only be present certain times of year / may migrate ;
73
State three processes that add carbon to the atmosphere (3)
respiration;
combustion / burning (fossil fuels/trees);
decomposition;
74
State the source of energy for a producer (1)
the sun
75
Suggest three reasons for removing trees from an area of land (3)
farming / agriculture / grazing / crop land / production of food;
mining / mineral extraction;
timber extraction / logging / paper / furniture;
roads / infrastructure;
settlements / urbanisation / industrialisation / building materials;
dams / reservoirs / HEP;
fuel;
76
Explain the impacts of deforestation (7)
habitat loss; food sources depleted / disruption to food chain;
loss of biodiversity / migration of species / extinction; genetic depletion;
soil erosion; no roots to bind soil;
soil washed away / water erosion; soil blown away / wind erosion;
decreased soil fertility / loss of nutrients / reduced organic material; desertification / land degradation;
lower crop yields; trees act as wind breaks;
(river) flooding; lack of interception;
increased surface runoff / reduced infiltration rates; more sediment carried by rivers;
Drought / decreased rainfall; lower (evapo)transpiration rates;
climate change / global warming / enhanced greenhouse effect; less photosynthesis;
less carbon dioxide removed from atmosphere / more carbon dioxide in atmosphere;
less carbon sinks / stores;
(Human impact) relocation of indigenous people; removal of livelihood / reduction of tourism;
77
State two reasons, other than soil erosion, why forests need to be conserved (2)
as a carbon, sink / store;
maintain biodiversity;
plants may be source of medicinal drugs / eq ;
for sustainability of supply of forest products / food;
78
Describe how trees reduce soil erosion (2)
interception of rain (reduces force of rain on the ground);
roots, hold soil / improve drainage / bind soil;
stabilise slopes;
reduce the force of winds / act as wind breaks;
less run off;
79
The effectiveness of national parks as a method for conserving biodiversity depends on the
interactions shown in the diagram. Suggest reasons why (5)
all three interactions required for success;
tourists need to respect, wildlife / habitats / ecosystem;
employees / rangers / guides, needed to work in park;
residents need to manage resources sustainably;
visitors provide money for national park activities;
government(s) needed for, legislation / laws / regulations;
wildlife need to, live / breed / feed, in habitats;
people need to deal with invasive species;
reintroduce species from captive breeding;
control populations to protect habitats of different species;
habitats provide place for wildlife and people to live in;
habitats provide resources for people;
managed timber extraction;
medicinal plants;
genetic resources / gene bank;
80
Explain how trees help to reduce carbon emissions (2)
(trees) absorb carbon dioxide;
store the carbon;
due to photosynthesis;
6CO2 + 6H2O → C6H12O6 + 6O2 /
carbon dioxide + water → glucose + oxygen;
81
Suggest four benefits of asking local people to complete bat population surveys (4)
local knowledge of, where bats are / when bats active;
many people can help;
low cost;
large amount of data can be collected;
data can be collected quickly;
raises awareness of the animal;
82
State two ways pollination can occur (2)
wind;
insects;
birds;
self-pollination;
83
State why a pilot questionnaire is carried out before the main questionnaire (1)
test whether questions are, suitable / clear;
test whether sampling methods are suitable;
identify any problems with the questions;
check that answers can be easily analysed;
84
Suggest reasons why Halley scientific research station in Antarctica is built on giant metal skis, with legs that can be adjusted (4)
easily moved;
height above ice can be increased;
legs can be removed / stops it getting buried / stops legs getting stuck / reduces land pollution;
increases surface area / stops sinking;
idea of durability or strength of metal;
85
The accommodation is built using insulating material that is very good at reducing heat
loss. Suggest two reasons why this is important at Halley scientific research station in Antarctica (2)
cold temperatures / keep people warm;
reducing energy use or energy resources / increased efficiency ;
all energy resources must be brought in;
(in cold) machinery stops working;
86
The waste management policy at Halley is to:
* minimise the quantity of waste produced
* reuse and recycle
* remove all waste from Antarctica, apart from sewage and food waste. Suggest reasons why it is important to minimise the quantity of waste produced at Halley scientific research station in Antarctica (2)
costly to remove;
difficult to store / reduces quantity to store;
difficult to transport;
less energy needed to remove the waste;
prevents, visual /smell / water / atmospheric pollution;
87
Suggest why sewage and food waste are not removed from Antarctica (1)
large amounts / difficult to transport / long distance to transport;
idea that transportation increases risk of disease or water pollution;
smell;
88
State three abiotic components in an ecosystem (3)
temperature;
humidity / water;
oxygen;
salinity;
light;
pH;
89
Suggest three reasons why the number of questionnaires returned was fewer than the
number of farmers selected for survey (3)
did not grow crops / were not arable farmers;
declined the survey / did not want to do it;
unavailable / too busy working / lack of time;
unwell / had died;
did not speak the same language (as the questionnaire);
illiterate / could not read;
questionnaires lost (in post);
stopped being farmers;
90
Suggest a method the student can use to select the nine trees at random (2)
identifying trees: give a number or letter to each tree;
random selection method: number generator / numbers out of a bag / phone book / number table;
91
Describe how timber extraction can be done to maintain biodiversity (2)
selective logging / sustainable harvesting;
species, not made extinct / can recover;
replant native species;
protected zones in the forest;
92
Describe how the student can use a quadrat to record the number of different plant species (5)
max two from quadrats:
quadrat of stated dimensions, e.g. 1
m2;
quadrat placed at, regular intervals / stated intervals;
sample all (three) transects;
counting:
count the number of species (in the quadrat);
description of how to deal with plants partially in an quadrat;
recording:
record number in a table;
repeating:
repeat same investigation;
repeating on different days;
93
Explain why plants are called producers (2)
photosynthesis;
chlorophyll absorbs light energy;
reactants: carbon dioxide and water;
products: glucose and oxygen;
light energy to chemical energy;
94
Explain the flow of energy through this food web (3)
energy transfers when organisms eaten / stated example of feeding from food web e.g. plant eaten by rabbit;
lost as heat;
idea of only 10% of energy passed between levels / 90% is lost;
lost through:
respiration;
digestion;
(excreted) waste (products);
movement;
death / decomposition;
maintaining body temperature / thermoregulation;
feeding / consumers do not consume the whole organism;
reproduction;
95
Explain how seed banks and zoos can help to maintain biodiversity (6)
(both) prevents extinction / protects endangered species;
seeds / animals can be reintroduced into wild;
max five seed banks:
maintains genetic record / source of genes;
development of new plants, e.g. drought-resistant wheat;
development of medicines;
max five zoos:
allows (captive) breeding;
reduces impact of, predation / hunting / poaching;
prevents inbreeding / international cooperation;
education / awareness;
96
Describe one way the fish farmer can select a representative sample of local people to
answer the questionnaire (2)
random: number generator / names in hat
systematic: every nth person;
97
State three abiotic factors that affect the growth of farmed fish (3)
temperature;
water;
oxygen (level);
salinity;
light (intensity);
pH (water);
98
Suggest three ways the student can confirm the results of the investigation (3)
same experiment;
greater number of trees / more than 5 trees;
different tree species;
different, soils / locations;
continue over longer time period / carry on over more years;
99
Explain why the energy in the body of the flamingo is dependent on chlorophyll (4)
(chlorophyll) in, producer / phytoplankton;
needed for photosynthesis;
uses carbon dioxide and water;
uses (Sun) light (energy);
to produce, glucose / sugar / (store) chemical energy;
energy moves (along food chain);
100
Suggest strategies to protect the Caribbean flamingos on Inagua Island (4)
preserve habitat;
introduce:
national parks;
captive breeding / zoos ;
wildlife, wardens / guides;
laws to give them protected status;
control:
disturbance by people / limit numbers of tourists;
predators e.g. vultures;
shrimp fishing;
hunting / fines for illegal poaching;
101
Describe a method for estimating the population of Caribbean flamingos on Inagua Island (5)
described method of dividing island or lake;
random / systematic sampling or method described;
count the number of flamingos;
at a set time or date;
record results, in a table / using a tally system;
idea of scaling up to whole area;
repeat and average;
102
Suggest how air temperature can affect the salinity of the lake (2)
the higher the temperature, the greater the evaporation of water;
(as water evaporates) the salinity or concentration increases;
103
Suggest three ways that the survey can be improved (3)
more questions;
ask open questions;
larger sample size / ask more people / make sample more representative;
ensure participants are residents / make sure tourists are not surveyed;
survey equal numbers of, different age groups / males and females;
repeat on different days;
repeat in different locations;
104
Explain two other strategies the government can use to manage the harvest of spiny lobsters (4)
any two strategies:
limit size of lobster you can harvest / only catch larger lobsters;
protect female lobsters (with eggs);
quotas;
closed seasons;
protected areas and reserves;
conservation laws, e.g. licences for harvesting;
monitor and enforce;
any two explanations that fit the strategies:
allows immature lobster to reach breeding age;
females produce massive amounts of eggs / one male can fertilise eggs from many females;
prevents overfishing;
allows lobster to breed;
allows larvae to spread from protected area;
limits the number of, fishermen / fishing days / boats;
ensure people are following the rules;
105
Describe the benefits and limitations of training sharks to pray on lionfish for controlling the population of lionfish (5)
benefits:
biological control;
sharks prey regularly on lionfish / no further training needed;
only lionfish killed / no bycatch;
job / income, opportunity;
limitations:
requires divers to train sharks;
could be dangerous for the diver;
training sharks is difficult;
expensive;
labour intensive / time-consuming;
population of lionfish is too high / lionfish can reproduce too quickly;
lionfish spread over too large of an area;
106
Define the term seed bank (1)
a store for seeds / a gene bank (for plants using their seeds);
107
Explain why scientists are concerned about the impact of lionfish on the ecosystem of the area (4)
lionfish are inedible;
therefore nothing will feed on them (no predators);
eat large quantities;
impact on food web;
decrease in populations of small fish;
introduced/invasive species (to the Atlantic Ocean);
means competition to other (native) organisms;
lay large quantities of eggs;
large population increase;
108
Suggest reasons why people have cleared forests in Ethiopia (3)
use of land for agriculture;
use of wood for fuel / construction / furniture / logging;
to clear land for mineral extraction / mining;
use of land for towns / urbanisation / roads / industry;
use of land for reservoirs / dams;
109
Suggest reasons why some of the trees planted may fail to grow (4)
lack of water / drought;
waterlogging;
lack of soil nutrients / poor soil;
pest problem / grazing livestock;
disease problem;
vandalism / human damage;
soil pollution;
110
Suggest reasons why people are not allowed to walk on the sand dunes (2)
trampling / dunes could collapse ;
kills or disturbs, plants / animals;
loss of habitat(s) ;
loss of some species / extinctions;
may drop litter;
introduces invasive species;
111
The company sends the questionnaire to every woman within 100km of the planned
factory location. Describe the limitations of this method (2)
only women questioned / not a representative sample ;
leads to biased results;
too much data;
will be expensive to conduct / analyse;
112
Explain why yes or no answers are used on questionnaires (1)
easier / quicker, to collect or analyse or process answers;
consistency of answer;
limits possible answers;
113
Describe a method the scientist can use to determine the number of plant species along
the 10-metre transect line in the sand dune reserve (4)
use of transect and quadrat:
divide the transect, systematically / in equal distances / stated distances;
defined size of quadrat, e.g. 25 cm x 25 cm, 50 cm x 50 cm, 1 m x 1 m;
count the number of plant species, every stated distance / in quadrat;
recording and processing data:
record the results, in a table / using a tally;
use a book to identify species;
repeat and take a mean;
114
Suggest reasons why using the data in the table is likely to give an underestimate of the total number of species in the 10km2 sand dune reserve (3)
the method only covers five (small) areas;
five transects are not representative;
lot of sand dune not sampled;
plants not evenly distributed;
longer transect needed (across whole area);
115
Explain the impacts of deforestation on the carbon cycle (4)
reduction in photosynthesis;
(trees act as) carbon sink or store;
fewer young or growing trees to remove / fewer mature trees store so more CO2 or carbon ;
change in decomposition (of leaves);
change in carbon added to the ground;
(deforestation leads to) increased carbon dioxide in atmosphere ;
imbalance between respiration and photosynthesis;
116
Describe how captive breeding programmes can increase the number of European brown bears (2)
young less likely to die from disease / access to vaccination;
other stated medical support;
breeding support / increased gene pool;
no threat from predators / hunting / poaching ;
not released into the wild until mature / strong;
no lack food / good food supply;
117
Suggest ways that extractive reserves benefit local tribes and communities (3)
right to follow traditional practices / way of life;
continue fishing / hunting / gathering / farming;
preserve their culture and way of life;
prevent destruction of their environment / area e.g. deforestation;
can live where ancestors lived ;
reduce risk of infection from outside contact;
118
Explain the functions of the three main zones of a biosphere reserve (3)
Core area: monitoring / research activities / no settlements / protect the ecosystem;
Buffer zone: controlled / limited access for people / eco-tourism / recreation / research, / education and training / some
limited settlements / local tribes / communities ;
Transition area: research / tourism / recreation / greater settlements / controlled human activities e.g. sustainable farming;
119
Describe how the pitfall trap shown in the diagram is used to sample organisms (3)
glass jar buried in soil;
organisms, walk / fall / captured into trap;
tall/ smooth sides prevent organisms escaping;
cover prevents rain filling it up with water / excess heat / gives shade;
number of, organisms / species, counted / classified;
periodic sampling;
120
Suggest two limitations of using this pitfall trap to sample organisms (2)
can only catch organisms that crawl / move on surface;
some might fly out;
can only catch small organisms (less than 10cm);
organisms in the trap might eat each other;
glass jar does not allow water to drain out;
not representative of the whole population;
121
Explain ways tourism can be made a sustainable activity (4)
developing sewage treatment;
offsetting carbon emissions;
encouraging ecotourism;
using renewable energy resources;
recycling waste caused by tourism, e.g. plastic bottles / litter collection;
educating, local people / tourists;
employing environmental guides / wardens;
funding to maintain natural beauty areas, e.g. forest, beaches;
(create a) national park / nature reserve / eq;
AVP; e.g. bikes / electric cars / laws against littering / prevent hunting;
122
Discuss whether tourism contributes to climate change (5)
Yes:
transport, e.g. planes and cars;
(combustion of fossil fuel) produces CO2 / GHG’s;
construction of materials for hotels, e.g. cement;
more energy / electricity (used on luxury items, e.g. swimming pools, saunas);
land is cleared for buildings;
fewer, trees / plants;
so less photosynthesis / eq; e.g. less carbon dioxide absorbed
destruction of carbon stores / sinks;
(intensive) farming practices to supply food for tourists;
increased methane from cattle;
AVP; e.g. burning more fossil fuels
No:
tourists would release similar amounts of C in their own country;
if they have enough money they will consume goods that may have contributed to climate change in their manufacture
anyway;
AVP;
