Topic 1
Identify the core values of anthropocentrism.
Using laws and regulation, taxation and subsidies to help manage the environment.
Define the terms species and population.
A species is a group of organisms that share common characteristics and that interbreed to produce fertile offspring.
A population is a group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.
Define evolution.
Evolution is a gradual change in the genetic character of populations over many generations, achieved largely through the mechanism of natural selection.
List an example of an aquatic food chain.
phytoplankton → krill → squid → sperm whale
Define cash cropping.
Cash cropping is growing a crop which has a high value on the (usually) export market and often replaces land that would be used otherwise to grow crops for local consumption. This is often driven by demand from markets in more economically developed countries. Examples include, cotton, chocolate, coffee, roses, bananas, oranges and vegetables for export such as green beans.
Describe open, closed, and isolated systems.
Open: Energy and matter can enter and leave the system.
Closed: Energy can enter and leave the system but all the matter stays in the system.
Isolated: Energy and matter are within the system and do not cross the system boundary.
Outline how photosynthesis and cellular respiration are linked.
Photosynthesis is an anabolic reaction, building glucose from the inputs of carbon dioxide and water using solar energy in chloroplasts while cellular respiration is a catabolic reaction, breaking down glucose using oxygen in mitochondria and releasing carbon dioxide and water.
List four reasons biodiversity is important.
Biodiversity is important for aesthetic, ecological, economic, ethical and social reasons.
Aesthetic: We should preserve it because it gives us pleasure to look upon a beautiful scene.
Ecological: Biodiversity is important to environmental systems (e.g. biogeochemical cycling) on which all life on earth depends. The higher the biodiversity the greater the stability of a system. Some systems have resilience to disturbance due to this high biodiversity.
Economic: Plant and animal resources provide the basis for human life
Genetic variation in plant and animal species provides the means for sustaining and improving farm production, forestry, animal husbandry and fisheries.
There are many species which have yet to have their commercial value discovered or exploited;
Many organisms contain chemicals which may be of medical or commercial value.
Ethical and Social: Some societies ascribe value to the local biodiversity and they have the right to have it protected.
Explain the term “water scarcity”.
Water means that there is a shortage of water for people in a given region. Water scarcity can be physical or economic. Physical water scarcity means the climate in that region is dry and/or the water is being over-extracted for human use, either for domestic, agricultural or industrial use. Economic water scarcity is when the physical infrastructure is not in place to ensure that clean safe water is available to the population.
Outline how monocultures reduce soil fertility.
Growing the same crop over large areas of land for repeated years means that the same minerals are always being taken from the soil. Farmers try to replace these using inorganic fertilisers.
Define tipping point and describe what often characterises a tipping point.
A tipping point is when a system has changed so much that it can no longer return to the equilibrium and it enters a new alternative stable state. The bleaching of coral is an example of this when the temperature change in the water means that the coral expels the symbiotic algae which no longer can re-enter the coral after a while and the coral dies.
Define and give an example of succession.
Succession is the process of change over time in an ecosystem involving pioneer, intermediate and climax communities. This results in changes to the structure and species composition of the communities present. These changes are brought about by the communities themselves. It is temporal in nature.
Primary succession examples include the formation of sand dunes, communities forming after a glacier retreats and communities forming following a volcanic eruption.
Secondary succession examples occur when soil is already developed, e.g. the growth of a forest following abandonment of a farmed field, regrowth following a wildfire.
List the factors used to determine the conservation status of a species.
Numbers
Distribution and Geographic Range
Habitat Fragmentation and Quality of Habitat
Degree of Specialisation
Reproductive Potential and Behaviour
Behaviour
Trophic Level
Probability of Extinction
Outline technologies that have made fishing more efficient, and consequently less sustainable.
Bottom trawling / dredging is particularly destructive to the sea bed and associated with the food trend of scallops. It is very unsustainable. Gill nets are dangerous to marine mammals, long lines can be 150 km long and catch non-target organisms (by-catch) such as sharks and turtles and purse seine nets can catch entire shoals of fish such as anchovies and herring. The use of technology such as spotter planes and radar mean that whole populations of organism can be caught, leaving nothing to chance.
Compare and contrast the reasons for food waste in MEDCs and LEDCs.
The amount of food waste generated in MEDCs and LEDCs is approximately one third of all the food produced. In developing countries the problem is chiefly one of inadequate harvest techniques, poor post-harvest management and logistics, lack of suitable infrastructure, processing and packaging, and lack of marketing information which would allow production to better match demand whereas in developing countries 40 percent of losses occur at post-harvest and processing levels while in industrialized countries more than 40 percent of losses happen at retail and consumer levels. Food losses during harvest and in storage translate into lost income for small farmers and into higher prices for poor consumers, the report noted. Reducing losses could therefore have an "immediate and significant" impact on their livelihoods and food security.
Explain the relationship between natural capital, natural income, and sustainability.
Natural capital are natural resources that can supply a natural income of goods or services. Natural income is the yield (amount/volume) obtained from natural resources without depleting the natural capital. Sustainability can only be achieved if the natural income allows for full replacement of the natural capital.
Explain how human activities can affect the carbon cycle.
Burning of fossil fuels, deforestation, urbanization and agriculture all impact the carbon cycle.
Burning fossil fuels directly adds carbon dioxide to the atmospheric store.
Deforestation removes the store of carbon labelled as plants. It can also release carbon from the soil store if the trees are burned and this adds carbon to the atmospheric store.
Urbanization reduces the land cover of plants reducing their potential to capture and store carbon.
Agriculture also changes land use, reducing the carbon stored by plants. The use of heavy machinery in intensive farming and the appication of inorganic fertilisers adds carbon to the atmospheric store.
Outline what makes an organisation an IGO, a GO, or an NGO.
An IGO - intergovernmental organisation - is an organisation sponsored by and working for a group of countries that set out its aims, e.g. IUCN or UNEP
A GO - a governmental organisation - is funded by a government and follows the political guidelines of that government. It may be politically aligned or not, depending upon the foundations of that country, e.g. The EPA in the USA
NGO - a non-governmental organisation - is funded by voluntary donations and sponsorship and is not usually politically affiliated, e.g. WWF or the Orangutan Foundation
Explain how temperature, salinity, and density drive ocean circulation.
Oceans are heated most at the equator, this causes temperature gradients which then lead to surface currents and movement of energy and matter away from the equator. As water reaches the most northerly and southerly locations on the Earth, the water has evaporated and leaves more saline water. This water is more dense and so sinks to the bottom of the ocean and moves by deep water currents in the thermo-saline ocean conveyor belt.
Explain how soil can be viewed as an ecosystem.
An ecosystem is a community and the physical environment with which it interacts. In soil there are many populations of organisms that live in the soil, like large organisms like moles or badgers to smaller invertebrates such as earthworms and beetle larvae and microorganims like bacteria and archaebacteria. Their physical environment consists of decomposing organic matter, inorganic rock particles (minerals), water and air.
Explain how DDT exemplifies a conflict between the utility of a pollutant and its effect on the environment.
In 2012 there were 207 million cases of malaria reported worldwide[1]. in 2015-6 Zika started emerging widely in Brazil with cases of microcephaly in newborns. DDT has been used successfully to reduce mosquito levels and thus reduce mosquito-transmitted diseases. DDT is a persistent organic pollutant and is prone to biomagnification through food chains. Rachel Carson won a great battle with the banning of DDT but some argue these costs are worth it in order to fight mosquito-transmitted diseases.
Evaluate the use of “Simpsons Diversity Index” in the measurement of biodiversity.
Similar habitats can be compared using D; a lower value in one habitat may indicate human impact. Low values of D in the Arctic tundra, however, may represent stable and ancient sites.
Evaluate the impact of human activity on the biodiversity of tropical biomes.
Tropical biomes are the most biodiverse areas on the planet. Humans are increasingly threatening these areas and drastically reducing their biodiversity. Activities include deforestation, conversion to plantations, exploitation for oil and mining of minerals such as gold.
There are conservation and rewilding efforts taking place in tropical areas but these are not keeping up with the detrimental activities.
Explain the process and impacts of eutrophication.
Eutrophication is the natural or artificial enrichment of a body of water, particularly with respect to nitrates and phosphates that results in depletion of the oxygen content of the water. Eutrophication is accelerated by human activities that add detergents, sewage or agricultural fertilizers to bodies of water.
The nutrient enrichment leads to algal blooms which can block light penetrating the water. As the algae use up the nutrients they start to die and fall to the bottom of the water body. Decomposition results in the oxygen being used up in the water and hence anoxic conditions. This leads to the death of organisms in the water and dead zones.
Evaluate the soil management strategies of a given commercial farming system and of a given subsistence farming system.
Iowa intensive corn production does not have grear soil management strategies. The soil is left exposed after harvesting for long periods of time, there are heavy inputs of inorganic fertilers, pesticides and genetically modifed seeds are used. There are no wind breaks or buffer zones.
The Zai technique used in Burkina Faso involves digging pits, filling them with dead plant material and animal manure and planting in these pits. The pits increase water infiltration and water holding capacity of the soil. They also encourage termites to visit the pits which increases the soil fertility and structure of the soil.