Environmental systems and societies ch. 3 & 4

Define the terms biodiversity, genetic diversity, species diversity and habitat diversity.

- Biodiverstity: the amount of biological or living diversity per unit area, includes species diversity, habitat diversity and genetic diversity. The conservation of biodiversity usually leads to the conservation of species and genetic diversity - Species diversity: the amount of species in an area - Genetic diversity: gene pool within a species (species with low genetic diversity are prone to extinction) - Habitat diversity: range of habitats in a area A way of measuring diversity: Simpsons diversity index D= [N(N-1)]/ [sigma n(n-1)] D= diversity index N= total number of organisms n= number of individuals of a particular species sigma = Sum of

Describe the nature and explain the implications of exponential growth in human populations.

- Exponential growth = refers to the growth rate which is increasingly rapid IMPLICATIONS OF EXPONENTIAL GROWTH OF HUMANS: . Huge amounts of extra resources are needed to feed, house and clothe and look after the increasing number of people. It can be argues that more developed countries (MEDCs) consume a lot more than less developed countries (LEDCs) . The main problem is that life expectancy is increasing, as are the number of elderly people, but social security systems are not. This is predicted in most countries apart from North & Latin America.

Outline soil conservation measures

1. mechanical methods to reduce water flow: - Include binding, terracing and contour ploughing. The key is to prevent or slow down the movement of rain water down a slope. - Land around gullies can be fenced off or dams can be built to reduce water flow 2. Cropping soil husbandry methods against water and wind damage - Planting on top of soil as a layer of protection 3. Management of salt affected soils - Flush water on it - Apply chemicals

Define the term non‑renewable natural capital.

A non-renewable resource = a resource which cannot be replenished within a timescale of the same order as that at which they are taken from the environment. Non-renewable (except on a geological timescale) forms of natural capital, such as fossil fuel and minerals, are analogous to inventories: any use implies liquidating part of the stock.

Define the term renewable

A renewable resource Is a natural resource that can be replaces by natural productivity as soon as they have been used up. Renewable natural capital, such as living species and ecosystems, is self-producing and self-maintaining and uses solar energy and photosynthesis. This natural capital can yield marketable goods such as wood fibre, but may also provide unaccounted essential services when left in place, for example, climate regulation.

Describe the Earth's water budget

Almost all water is saltwater (97.5%), and very little is freshwater (2.5%). OF the freshwater, 68% is glaciers and permanent snow: the rest is lakes, rivers and ground water Turnover time = the time it takes for the water to replace itself.

State the arguments for preserving species and habitats.

Arguments for preserving species and habitats: FOREST CONSERVATION: - Produces sustainable resources - reduces drainage - Maintains oxygen/carbon (both balances and reduces it), and therefore reduces global warming - Maintain biodiversity (habitat complexity, niche availability, number of species) Economic values of biodiversity: 1. Natural product (Timber, medicine) 2. Food Non-economic values of biodiversity: 1. Ecosystems productivity (pollination, decomposers e.g. worms fungi) 2. Scientific reasons - can not explore knowledge about plants if there are none 3. Education - part of programmes 4. Genetic diversity - potential sources 5. Recreation and ecotourism 6. Aesthetic values (i.e. it's pretty) 7. Human rights - indigenous people can continue to live in them Ethical values - each species on earth has the right to exists

Describe and explain the relationship between population, resource consumption and technological development, and their influence on carrying capacity and material economic growth.

Because technology plays such a large role in human life, many economists argue that human carrying capacity can be expanded continuously through technological innovation. For example, if we learn to use energy and material twice as efficiently, we can double the population or the use of energy without necessarily increasing the impact (load) imposed on the environment. However, to compensate for foreseeable population growth and the economic growth that is deemed necessary, especially in developing countries, it is suggested that efficiency would have to be raised by a factor of 4 to 10 to remain within global carrying capacity.

Explain the difficulties in applying the concept of carrying capacity to local human populations.

By examining carefully the requirements of a given species and the resources available, it might be possible to estimate the carrying capacity of that environment for the species. This is problematic in the case of human populations for a number of reasons. The range of resources used by humans is usually much greater than for any other species. Furthermore, when one resource becomes limiting, humans show great ingenuity in substituting one resource for another. Resource requirements vary according to lifestyles, which differ from time to time and from population to population. Technological developments give rise to continual changes in the resources required and available for consumption. Human populations also regularly import resources from outside their immediate environment, which enables them to grow beyond the boundaries set by their local resources and increases their carrying capacity. While importing resources in this way increases the carrying capacity for the local population, it has no influence on global carrying capacity. All these variables make it practically impossible to make reliable estimates of carrying capacities for human populations.

Describe the case histories of three different species: one that has become extinct, another that is critically endangered, and a third species whose conservation status has been improved by intervention

CASE HISTORY - one that has become extinct 1. Falkland island wolf - Found on: Falkland island - Ecological role: lived in borrows, are birds - Pressures: Island settler considered the wolf to be a threat to their sheep, shot them all. - Consequences: affected food chain CASE HISTORY - is critically endangered 2. Iberian lynx (Lynx pardinus) - Description: predator, eats rabbits - Reason for endangered status: they need a big hunting area, but their habitat is being destroyed - Ecological role: Ate rabbits, kill other carnivores - Pressures: to specialized diet, destroyed hunting area and shot. - Method for restoration: Protection under law in spain & portugal, educational programmes CASE HISTORY - species whose conservation status has been improved by intervention 3. American bald eagle (Haliaeetus leucocephulus) - Description: One of the largest birds in north america. - Ecological role: Live near large bodies of open water, feed on fish and small animals - Reason for endangered status: due to DDT - Method for restoration: Under law restrictions & ban on DDT

Describe the case history of a natural area of biological significance that is threatened by human activities.

CASE HISTORY- Natural area The great barrier reef - was threatened by human activities - ruined by tourists - ruined by oil spills - By global warming: say that the oceans are getting warmer, therefore the habitat is changing and may hurt the animals within it. - Natural threats: the starfish that kills the coral reefs, and that have increased due to human activity. Coral reefs are able to withstand some threats, but the current combined effect of human and naturals processes can lead to the irreversible damage to the reef, and the species that depend on is in turn, these effects can lead of the breakdown of the reef ecosystem. The problems may well become irreversible and the ecosystem will not recover even if the threats stop. Loss of biodiversity and the valuable role that the ecosystem provides will inevitably lead to a reduction in its value as an economic resource.

Evaluate soil management strategies in a named commercial farming system and in a named subsistence farming system.

CASE STUDIES: 1. Commercial farming (Big farming for profit) Soil conservation on the great planes of the USA. There was a period of time where there was high water erosion and demand for food at the same time (1930) How they fixed this: Contour ploughing, shallow ploughing, temporary plants were grown - increase mineral conservation Later in: Fertilizers and herbisides were used EVALUATION: +reduced soil salinity and annual weeds + greater conservation of organic matter - others weeds become different to control - Fertiliser placement is difficult 2. Subsistence farming (small farm to feed family) Mexican Indians practice agricultural farming. They plant many different crops that benefited from each other. E.g. Mays ( which extracts minerals) and beans (which returns minerals) This creates high NPP, and therefore the Indians were able to maintain soil quality by working with nature EVALUATION: + Maintain soil weel - Would not have been good for larger areas

Evaluate the success of a named protected area.

CASE STUDY: Danum valley conservation area, Malasyian Borneo The granting of protected status to a species or ecosystem is no guarantee of protection without community support, adequate funding and proper research. In north-eastern Borneo, the third largest island in the world, a large area of commercial forest owned by a foundation, is a model of how effective conservation can be matched with economic needs.

Explain how absolute reductions in energy and material use, reuse and recycling can affect human carrying capacity.

Carrying capacity can be changed by: - Recycling: the processing of industrial household waste so that materials can be reused - Re-use: multiple use of a product Human carrying capacity is determined by the rate of energy and material consumption, the level of pollution and the extent of human interference in global life-support systems. While reuse and recycling reduce these impacts, they can also increase human carrying capacity. This can increase our carrying capacity as they reduce the impacts of pollution, energy and material consumption consumption and human interference in global life support systems which determine the human carrying capacity.

Calculate and explain, from given data, the values of crude birth rate, crude death rate, fertility, doubling time and natural increase rate.

Crude birth rate: CBR = (total number of births/ total population) * 100 Age specific birth rate = (total number of births/1000 women of any specified year group) What may affect this: Social factors, e.g. the general level of education and economic factors, e.g. economic prosperity = people have a lot of kids so as to have people who can pay and work for them when they get older. Crude death rate CDR = (total number of births/ total population) * 100 Infant mortality rate is the total number of children aged under 1 per 1000 live births. Neither include age of specific population or sex structure What may affect this: health care, sanitation, availability of fresh water, malnutrition and prevalence of diseases Doubling time: DT (years) = 70 / %growth rate Natural increase rate: NIR = CBR - CDR

Explain the relationships among ecosystem stability, diversity, succession and habitat.

Definitions: - Succession: the orderly process of change in a community over time. - Stable ecosystem: is an ecosystem that does not change it's composition of species and habitat (desert) - Unstable habitat: is an ecosystem that is changing in its composition of species, variety of genes and niches. - Sere: A sere is the set of communities that succeed one another over the course of succession at a given location Organisms can colonize isolated land using several mechanisms: air (flying/passive transportation), sea (swimming /flaoting) and Animal (attached to the animal). They can also access lang through different types of dispersal: 1. Jump dispersal (long-distance dispersal to remote areas of one of few individuals) 2. Diffusion (populations slowly spread of species at the edge of their ranges into new areas) 3. Secular migration (dispersal over geological timescales) HOWEVER; Diversity changes through succession. Greater habitat diversity leads to greater species diversity. A complex and ecosystem with its variety of nutrients and energy pathways provides stability. Human activities often simplify ecosystems, rednf them unstable, for examples: North america wheat farms versus tall grass prairie. An ecosystems capacity to survive change may depend on: 1. diversity - the number of species present 2. Resilience - ability of a system to recover after a disturbance 3. Interia - the number of species present and their populations

State and explain the criteria used to design protected areas.

Designers have been using ideas to ensure maximum preservation of species within conservation areas: - Better to choose a big area, rather than a small (more niches etc. in the same region) a single big area is better rather than many smaller (despite them being the same size) - Area: there are many different area sizes (?) the bigger the better - Edge effect: change in abiotic factors at the end of the protected area may attract species that don't exist in the protected area and ruin it. - Shape: Better with a big circle because too many edges give the edge effect. - Corridors: are preferable to no corridors because animals can migrate Buffer zone - making no 'sharp edges' to the protected area, there are areas which will help protect the protected area around them. Successful protected areas include: - Fundings by the government - Involvement with government agencies - Educational programmes - Local support - Management programmes - High profile animals to attract visitors (e.g. elephants) - Scientific research programmes Buffer zones: and area outside a conservation area,contain habitats. These areas minimize disturbance from outside influences such as people, agriculture or invasion by diseases. Make the conservation area more successful

Calculate from appropriate data the ecological footprint of a given population, stating the approximations and assumptions involved.

EF (per capita land requirement for food production) = (per capita food consumptions) / (mean food production of local arable land) per capita land requirement for absorbing waste CO2 from fossil fuels (ha) = (per capita carbon dioxide emmission) /(net carbon fixation per hectareof local natural vegetation) The total land requirement (ecological footprint)can then be calculated as the sum of these two per capita requirements, multiplied by the total population. Although the accurate calculation of an ecological footprint might be very complex, an approximation can be achieved. This calculation clearly ignores the land or water required to provide any aquatic and atmospheric resources, assimilate wastes other than carbon dioxide (CO2), produce the energy and material subsidies imported to the arable land for increasing yields, replace loss of productive land through urbanization, and so on.

Explain the concept of resources in terms of natural income.

Economists describe resources as "natural capital". This is because, if properly managed, renewable and replentishable resources are forms of wealth that can produce income indefinitely in the form of valuable goods and services. This income may consist of marketable commodities such as timber and grain (goods) or may be in the form of ecological services such as the flood and erosion protection provided by forests (services). Similarly, non-renewable resources can be considered in parallel to those forms of economic capital that cannot generate wealth without liquidation of the estate.

Describe and explain the factors that may make species more or less prone to extinction.

Factors that make species more or less prone to extinction: 1. Small population size: if they live on small islands or have low genetic diversity 2. Limited distribution: if they all live in one place and all the species die there, there are more more anywhere else. 3. Low reproductive rate; species that live a long time had a low reproductive rate and less offspring 4. Non-competitive behavior: some species are helpless under the pressure of hunting and predation, they are sitting targets if they have poor defensive instincts. 5. Large mammals: a significant source of meat, vulnerable to over hunting (especially by humans). Also, it may be difficult for them to find places to live. 6. Valuable products: they are at risk as humans desire them

Describe and evaluate the sustainability of freshwater resource usage with reference to a case study.

Human populations require water for home use, agriculture, industry and hydroelectric power. Given the scarcity of freshwater, the pressure on this resource is great and likely to increase, particularly in certain parts of the world. Without sustainable use, humans are likely to face many problems - there are already a billion people living without clean water. In combination with climate change and disrupted rainfall patterns, this is not good. The demand for water has continued to grow throughout the idustrial period, and is still expanding in both MEDCs (we wash more frequently, water gardens and wash cars) and LEDCs (because they are an expanding population and are changing agricultural practice). water resources can be managed sustainably if individuals and communities make changes locally, and this is supported by the government. Sustainable use in cities and populated areas could be reached by: - making new buildings more water-efficient - offsetting new demand by fitting homes and other buildings with more water-efficient appliances (e.g. toilets) - expanding metering to encourage households to use water more efficiently If we do not make changes, there will not be enough of this non-renewable resource to go around for anybody. CASE STUDY: Water shortage in the middle east The middle east has little fresh-water and high population, this meant that there was an increased excess demand for water. When there was a drought in Israel, this meant that they had to find new ways to find water, but the drought severely affected agriculture, quality of life and population growth and the drought made it even worse. This could lead to conflicts between the countries that shared the water supply.

Describe and explain the differences between the ecological footprints of two human populations, one from an LEDC and one from an MEDC.

In MEDCs, about twice as much energy in the diet is provided by animal products than in LEDCs. Grain production will be higher with intensive farming strategies. Populations more dependent on fossil fuels will have higher CO2 emissions. Fixation of CO2 is clearly dependent on climatic region and vegetation type. These and other factors will often explain the differences in the ecological footprints of populations in LEDCs and MEDCs. (Data for food consumption are often given in grain equivalents, so that a population with a meat‑rich diet would tend to consume a higher grain equivalent than a population that feeds directly on grain)

Discuss the view that the environment can have its own intrinsic value.

Intrinsic value = a value in its own right, irrespective of economic value. Aspects within the environment may not have an economic value (has no price or is maybe no useful) but has its own worth as a living factor on the planet. It can have a: - Ecological value: they are essential for human existence - Atheistic value: Visually attractive but have not price (e.g sunset) - Intrinsic value Organisms or ecosystems that are valued on aesthetic or intrinsic grounds may not provide commodities identifiable as either goods or services, and so remain unpriced or undervalued from an economic viewpoint. Organisms or ecosystems regarded as having intrinsic value, for instance from an ethical, spiritual or philosophical perspective, are valued regardless of their potential use to humans. Therefore, diverse perspectives may underlie the evaluation of natural capital. Attempts are being made to acknowledge diverse valuations of nature (for example, biodiversity, rate of depletion of natural resources) so that they may be weighed more rigorously against more common economic values (for example, gross national product (GNP)). However, some argue that these valuations are impossible to quantify and price realistically. Not surprisingly, much of the sustainability debate centers on the problem of how to weigh conflicting values in our treatment of natural capital.

State that isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring.

Isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring. Isolation is the process by which two populations become separated by geographical, behavioral, genetic or reproductive factors. If gene slow between the two sub-populations is prevented, new species may evolve. Geographical variance may occur in rivers and mountains, but geographical dispersal occurs as a result of emigration

Discuss the use of models in predicting the growth of human populations.

It is very difficult to predict the growth of human populations as their are many factors influencing birth and death rates. Factors influencing birth rates are e.g: - population age & stucture - status in women - education in society - availability of contraceptives Factors influencing death rates are e.g: - Age and structure of populations - availability of clean water - provision of health care. To predict how these factors will change is very difficult and thus makes it difficult to predict how populations will change over time. An example of how difficult it can be to predict the growth of human populations are, an example is Thomas Maltus predicted in the late 1700 that there wouldn't be enough found for people by the middle of the 1900

Outline the issues involved in the imbalance in global food supply.

LEDCs: - suffer from undernourishment and malnutrition - 3/4 of the worlds population in innadequately fed - Growing populations - more people to feed in the world today - MEDCs have protectionist measures that lead to an even larger imbalance of food supply - Global warming/ climate change has also affected food supply, as well as technology

Discuss how national and international development policies and cultural influences can affect human population dynamics and growth.

Many policy factors influence human population growth. Domestic and international development policies (which target the death rate through agricultural development, improved public health and sanitation, and better service infrastructure) may stimulate rapid population growth by lowering mortality without significantly affecting fertility. Some analysts believe that birth rates will come down by themselves as economic welfare improves and that the population problem is therefore better solved through policies to stimulate economic growth. Education about birth control encourages family planning. Parents may be dependent on their children for support in their later years and this may create an incentive to have many children. Urbanization may also be a factor in reducing crude birth rates. Policies directed towards the education of women, enabling women to have greater personal and economic independence, may be the most effective method for reducing population pressure.

Compare and contrast the role and activities of intergovernmental and non‑governmental organizations in preserving and restoring ecosystems and biodiversity.

NON-GOVERNMENT ORGANISATIONS (NGO): - Are not run by, funded by, or influenced by governments e.g. Greenpeace - Tend to be more radical (and often have to be so as to get their message across heard) - They tend to be field-based, gathering information to back up their arguments. Use of media: Advertise on popular cahnels & leaflets Speed of response:Can be rapid and regular Diplomatic constraints: Are not run by, funded by, or influenced by governments Political influences: No direct political influence Enforceability: rely on public pressure rather than legal power to influence governments: no power to change laws INTERGOVERNMENTAL ORGANISATIONS - (UNEP) are bodies established through international agreements to protect the environment and bring together governments to work together on an international scale They tend to be more conservative (less controversial) They tend to gather information from scientific research which they pay for Use of media: professional media liaisons Speed of response: Fairly slow, must meet legal requierements Diplomatic constraints: Cannot give opinion without consulting lawyers and other countries because they represent many nations Political influences: Great - direct acces to governemnts of many countries Enforceability: Through international agreements and laws

Define the term replenishable

Replenishable resource = a non-living resource which are continuously resorted by natural processes as soon as they are used up. Replenishable natural capital, such as groundwater and the ozone layer, is nonliving but is also often dependent on the solar "engine" for renewal.

Outline the mechanism of natural selection as a possible driving force for speciation.

Natural selection => Evolution Charles Darwin came up with the theory of evolution 1806 Visited the Galapagos islands, which were volcanic islands He observed the birds on the different islands, and found that they were different due to different island conditions - they had adapted. Came up with "survival of the fittest" = the fittests, or the best adapted organisms, survive. The survivors reproduce and pass on their adaptive genes to the next generation. Over time, the populations gene pool changes and new species emerge. Speciation occurs as a result of the isolation (geographical or reproductive) of populations.

Outline the range of energy resources available to society.

Oil Coal gas nuclear biomass hydro solar energy wind geothermal bio-fuels Societies adapt resources depending on what is available, this may not always be an ecofriendly choice

Explain how plate activity has influenced evolution and biodiversity.

Plate tectonics = the movement of the 8 major and minor internally rigid plates of the earths lithosphere in relation to each other and the partially mobile asthenosphere below. The movement of these plates create earthquakes, mountains and volcanoes. Geographical isolation has lead to changes on earth, e.g. movement of countries. There are organisms that have ended up being on the other continent, which has lead to them evolving differently. Isolated gene pools cannot interbreed, and after long periods of time the different organisms adapt to local surroundings until the different populations become genetically distinct, forming new species. Thus, plate tectonics can affect biodiversity and evolution.

Analyse age/sex pyramids and diagrams showing demographic transition models.

Popolation pyramids tell us a great deal of information about age and the sex-structure os a population: - wide base= high birth rate - Narrowing base = suggests falling birth rate - Near or straight vertical sides = falling birth rate - Concave slopes characterize high death rates While many of the more economically developed countries (MEDCs) have a declining population size, that of many of the less economically developed countries (LEDCs) is rising rapidly. The position of various countries on the demographic transition model reflects their development stages.

Outline the factors used to determine a species' Red List conservation status.

Red list= an inventory of all threatened species A range of factors sed to determine a species' Red List conservation status include: 1. Population size 2. reduction of population size 3. number of mature individuals 4. geographical range 5. Quality of habitat 6. Area of occupation 7. Probability of extinction

Compare and contrast the structure and properties of sand, clay and loam soils, including their effect on primary productivity.

SAND: - high drainage - low primary productivity - high mineral content - Bad water holding capacity - High air spaces - No life in sand CLAY - High mineral content - Low drainage - Holds water well - No air spaces - Some primary production SILT - Quite high mineral content - Medium drainage capacity - Some water holding capacity - Enough air space for primary productivity

Outline the processes and consequences of soil degradation.

SOIL DEGRADATION: the decrease in quality or quantity of soil due to: - Wind erosion - Water erosion - Eutrophication - Acidification - Climatic change (see below) - Human activity HOW CLIMATIC CHANGE AFFECTS SOIL 1. Higher temperatures cause higher decomposition rates of organic matter 2. More precipitation and flooding cause more erosion 3. More droughts cause wind erosion HOW HUMAN ACTIVITY AFFECTS SOIL 1. Overgrazing of animals reduces vegetation cover and leaves the surface vulnerable 2. Cultivation leads to the exposure of bare soil surface before planting and harvesting. Generates runoff and creates rills and gullies. Irrigation in hot areas can lead to salinization. 3. Deforestation - leads to erotion - roots died, soil is exposed to wind and water

Outline how soil systems integrate aspects of living systems.

Soil is a major component of the worlds ecosystem and they form the outermost layers of the earths surface. Interfaces are formed at the earths atmosphere, lithosphere (rocks), biosphere (living matter) and hydrosphere (water). Soils are a vital resource for humans but they take a long time to develop - are therefore considered to be a non-renewable resource. SOIL PROFILES (image of the different horizons of soil in the earth, i.e. the different distinguishable layers) O - Organic horizon - undecomposed litter, well-decomposed humus A - A mixed mineral - organic horizon (humus) E - Eluvial or leached horizon - strongly leached B - Illuvial or deposited horizon - contains minerals that were in E C - Bedrock - rock or unconsolidated loose deposists

Discuss and evaluate the strengths and weaknesses of the speciesbased approach to conservation.

Species-based approach to conservation CITES -Conservation -International -Trade in -Endangered -Species Limitations: - Voluntary (will not attract those who do not already agree, easy to sign if you are not affected) - Penalties may not match the gravity of the crime. Role of Zoo in conservation: How to select: -Level of threat -Focus -Financially - long term -Location - developing countries -Ex situ (in unnatural habitat e.g. zoo) - in situ (conservation in local habitat) 5 freedoms animals should get in a zoo: 1. Hunger, thirst, malnutrition 2. freedom from thermical and physical stress 3. Pain, injury, disease 4. to express normal behaviour 5. from fear and distress

Explain the concept of sustainability in terms of natural capital and natural income.

Sustainability= the use of global resources at a rate that allows future generations to use is as well, and that minimize damage to the environment. Any society that supports itself in part by depleting essential forms of natural capital is unsustainable. If human well-being is dependent on the goods and services provided by certain forms of natural capital, then longterm harvest (or pollution) rates should not exceed rates of capital renewal. Sustainability means living, within the means of nature, on the "interest" or sustainable income generated by natural capital.

Calculate and explain sustainable yield from given data.

Sustainable yield (SY) may be calculated as the rate of increase in natural capital, that is, that which can be exploited without depleting the original stock or its potential for replenishment. For example, the annual sustainable yield for a given crop may be estimated simply as the annual gain in biomass or energy through growth and recruitment. SY= [total biomes at t+1/ total energy] - [total biomes at t/ total energy] t+1= the time of the original capital + yeild or SY= (annual growth and recruitment) - (annual death and emigration)

Compare and contrast the inputs and outputs of materials and energy (energy efficiency), the system characteristics, and evaluate the relative environmental impacts for two named food production systems.

Terrestrial farming systems can be divided into several types: 1) commercial farming (for profit) 2) Subsitence farming (for families) These can both be 1) Intensive farms = small with high output or... 2) Extensive farms = larger, with more money put into them Inputs and outputs: - Fuel = pollutants - Labour = food - Fertilizer = crops Commercial farming case study: 1) Commercial salmon farming exists in Norway and Scotland involves the feeding of bred or wild fish in open nets commercial 2. rice‑fish farming in Thailand. Factors to be considered should include: • inputs—for example, fertilizers (artificial and natural), irrigation water, pesticides, fossil fuels, food distribution, human labour, seed, breeding stock • system characteristics—for example, selective breeding, genetically engineered organisms, monoculture versus polyculture, sustainability • environmental impact—for example, pollution, habitat loss, reduction in biodiversity, soil erosion • outputs—for example, food quality and quantity, pollutants, soil erosion.

Compare and contrast the efficiency of terrestrial and aquatic food production systems.

Terrestrial systems: - most food is harvested from lower trophic levels - Systems that produce crops are more energy efficient that those that produce livestock - however livestock is still produced due to taste: Aquatic systems: - Most food is harvested from higher food chains and higher trophic levels. This makes it less efficient that terrestrial crops - However, less energy is lost in higher food chains levels - But this does not make much different as organisms already have little absorption of energy due to the reflection of sunlight

Explain the concept of an ecological footprint as a model for assessing the demands that human populations make on their environment.

The ecological footprint of a population is the area of land, in the same vicinity as the population, that would be required to provide all the population's resources and assimilate all its wastes. As a model, it is able to provide a quantitative estimate of human carrying capacity. It is, in fact, the inverse of carrying capacity. It refers to the area required to sustainably support a given population rather than the population that a given area can sustainably support.

Discuss current estimates of numbers of species and past and present rates of species extinction.

The fossil records show that there have been 5 extinction periods in the past, and approximately 100 million years between them. This is not actually knows, but are guesses. Our phase is phase 6 and it can be divided into 2 discrete phases: 1) When humans started to disperse 2) When humans turned to agriculture Scientists believe that, unlike previous abiotic extinctions, the six phase is a biotic (human made) extinction. Now with pollution, we are changing even faster. Past extinctions occurred suddenly over a relatively short time period, caused by environmental catastrophes. Animals and plants died from both the initial event and the short-term environmental turmoil that followed (e.g. climate change). The current mass extinction is happening at an even faster rate, which does not give species time to adapt to changing conditions. Some scientists say that 50% of species will be extinct by the end of the 21st century.

Discuss the concept of sustainable development.

The term "sustainable development" was first used in 1987 in Our Common Future (The Brundtland Report) and was defined as "development that meets current needs without compromising the ability of future generations to meet their own needs." The value of this approach is a matter of considerable debate and there is now no single definition for sustainable development. For example, some economists may view sustainable development as a stable annual return on investment regardless of the environmental impact, whereas some environmentalists may view it as a stable return without environmental degradation.

Explain the dynamic nature of the concept of a resource.

The value of the resource changes over the years due to how humans view it: it's status changes. A human advance culturally and technologically so does the value of resources, e.g. flint was important before to hunt but not anymore . - For example, uranium, due to the development of nuclear technology, has only recently become a valuable resource.

Identify factors that lead to loss of diversity.

These include: • natural hazard events (for example, volcanoes, drought, ice age, meteor impact) • habitat degradation, fragmentation and loss • agricultural practices (for example, monoculture, use of pesticides, use of genetically modified species) • introduction and/or escape of non-native species • pollution • hunting, collecting and harvesting. Rate of loss of biodiversity may vary from country to country depending on the ecosystems present, protection policies and monitoring, environmental viewpoints and stage of economic development.

Discuss the links that exist between social systems and food production systems.

This could be illustrated through the use of examples, such as: • the way in which the low population densities and belief systems of shifting cultivators links with the ecosystem of "slash and burn" agriculture= small parts of forests are cut down and burnt. The ash fertilizes the soil, which then enables new crops to grow. Then when the soil has been used the farmer moves to a new area. do this continuously, and then eventually come back to first area. • the link between the political economy of modern urban society, corporate capitalism and agro-ecosystems: cultivation has today become more commercial throughout the years - people try to maximize profit by mass-production - this ensured profit instead of meeting needs,

Discuss the perceived vulnerability of tropical rainforests and their relative value in contributing to global biodiversity.

Tropical rainforests: Close to the equator, wet seasons and high temperatures make the productive, high in biodiversity (house many species), very complex, 5.9% of the lands surface and include many niches. MUCH more vulnerable than timber forests. If the rainforest is destroyed and cut down, then the soil in the rainforest will contain less and less nutrients; meaning that new plants can't grow there. Erosion will occur and sweep away the thin lair of nutrients on the top of the soil, and then no new seeds will be able to grow, and thus no new vegetation. It is very difficult to restore such complex systems, especially when the soil quality is low. If ruined, a huge amount of the earths biodiversity will be gone as it houses so many species. GREEN POLITICS: is a political ideology which places an importance on ecological and environmental goals, and on achieving these goals through broad-based, grassroots participatory democracy. It was created in part by the threats to the rainforests and focuses on the way in which people are destroying nature for personal gain.

Evaluate the advantages and disadvantages of two contrasting energy sources.

WIND POWER: ADVANTAGES + environmentally friendly + different sizes + efficient + all countries have a windy area + can be placed in water + does not take up much space WIND POWER: DISADVANTAGES - Only work when there is wind - they are noisy - may be considered ugly - need many to produce enough energy - production of wind turbines pollute the environment NUCLEAR: ADVANTAGES + produce a lot of energy +does not produce carbon dioxide + reliable + do not take up much space NUCLEAR: DISADVANTAGES - produces nuclear (radioactive waste) - Huge accidents can occur - They are expensive and take a long time to build - Dangerous