3.1 The living environment
The emphasis should be placed on the interaction of living organisms with each other and their abiotic environment, and how an understanding of this can inform decisions that lead to sustainable human activities. Students must apply their understanding of these interactions in a wide range of contexts throughout this area.
Conditions for life on Earth
How the main conditions, which allowed early life to develop and survive on planet Earth, came about
Students should understand how the conditions of planet Earth allowed early life to develop and survive.
|
Content |
Additional information |
|---|---|
|
Atmosphere |
The mass of Earth and force of gravity retained an atmosphere. The atmosphere provided gaseous resources: carbon dioxide, methane, nitrogen. Atmospheric pressure and temperature maintained liquid water. |
|
Insolation |
A suitable temperature range was controlled by incoming insolation and its behaviour in the atmosphere. This was controlled by the surface albedo, absorption of infrared energy and the presence of the atmosphere. |
|
Position in the solar system |
Suitable temperatures were maintained by the distance from the Sun. |
|
Orbital behaviour |
The rotation and tilt of the Earth on its axis and its orbit around the Sun, controlled daily and seasonal variations in insolation and temperatures. |
|
Magnetosphere |
The magnetosphere provides protection from radiation: the Earth’s molten core produced a magnetic field (magnetosphere) that deflects solar radiation. |
How the presence of life on Earth has brought about environmental change
How biota have helped to maintain stability
|
Content |
Additional information |
|---|---|
| Oxygen production |
Oxygen was first produced by photosynthetic bacteria, then by algae and plants. |
| Ozone layer |
Ozone was produced by chemical reactions involving oxygen and ultraviolet light in the stratosphere. |
| Carbon sequestration |
Atmospheric carbon dioxide concentrations were reduced by photoautotrophs. |
| Biogeochemical cycles |
The processes of biogeochemical cycles are linked by living organisms, preventing the build-up of waste products or shortages of resources. |
How historical conditions for life were monitored in the past and how these methods have been developed over time
Students should understand how changes in monitoring methods have allowed more accurate estimation of past conditions on Earth.
|
Content |
Additional information |
|---|---|
|
Limitations of early methods. |
|
|
Improved methods. |
(See Research methods) |
Conservation of biodiversity
The importance of the conservation of biodiversity
Resources and how sustainable habitat management strategies can be used to secure future supplies
|
Content |
Additional information |
|---|---|
| Wood |
Timber for structural uses. |
| Fibres |
Plant and animal fibres. |
| Oils |
Uses of vegetable oils. |
| Fuels |
Biofuels. |
| New foods |
Many plant species have the potential for commercial cultivation. |
Knowledge and how decisions over habitat conservation can be made to protect those species that have not yet been investigated
|
Content |
Additional information |
|---|---|
| Biomimetics |
Students should understand that features of living organisms can be copied in the development of new structures and materials, eg:
|
| New medicines |
New medicines can be developed from the chemicals produced by plants and animals. |
| Physiological research |
Animal species may be more useful or practical than humans for physiological research. |
| Wildlife species as pest control agents |
Many wildlife species can be used to control agricultural pests. They may be predators, herbivores, parasites orpathogens. |
| Genetic resources |
New genes to improve crop genetic characteristics may be found in the wild relatives of the cultivated crops. The importance of Centres of Diversity/Vavilov centres for crop wild relatives (CWRs). |
Ecosystem services and their interaction with each other
Content | Additional information |
|---|---|
| Atmospheric composition | The role of living organisms in the regulation of the composition of the atmosphere: O2, CO2, water vapour. |
| Biogeochemical cycles | The importance of living organisms in biogeochemical cycles. |
| Interspecies relationships | Living organisms often provide services that aid the survival of other species, eg pollination, seed dispersal and habitat provision. |
| Soil maintenance | Living organisims are important in soil formation and erosion control, eg plants, detritivores, decomposers. |
How humans influence biodiversity, with examples in a range of different context
|
Content |
Additional information |
|---|---|
| Direct exploitation |
Populations of many species have been reduced by over-exploitation for resources or deliberate eradication, eg:
|
| Deliberate eradication | Eradication of predators and competitors. |
| Changes in abiotic factors |
Human activities may change the abiotic features of a habitat, making it more or less suitable for the survival of wildlife.
|
| Changes in biotic factors |
Changing the population size of one species often has an impact on the population size of other species.
|
| Habitat destruction |
Many human activities remove the natural communities of species:
|
Methods of conserving biodiversity
Setting conservation priorities
|
Content |
Additional information |
|---|---|
|
Students should understand that the conservation of biodiversity requires setting priorities about which species and communities are to be conserved. |
|
| International Union for Conservation of Nature (IUCN) criteria |
The roles of the IUCN:
Students should have knowledge of the criteria used by the IUCN to identify the species that should be prioritized for conservation. These are developed further elsewhere in the specification:
|
| Evolutionary uniqueness |
EDGE species (Evolutionary Distinct and Globally Endangered) are threatened by extinction and diverged from other taxa long ago so they have greater genetic differences. |
| Endemic species | Species found within a single area, especially if the population is small. |
| Keystone species |
Species whose survival is important for the survival of many other species. |
Legislation/protocols
|
Content |
Additional information |
|---|---|
|
How legislation and protocols protect species and habitats by establishing restrictions and management agreements. |
|
| Protection of habitats and species |
The key features of the Wildlife and Countryside Act (1981). Students should understand the different ways in which designated areas protect species and habitats by restricting activities and establishing management plans. Designated protected areas in the UK, eg:
|
| Trade Controls | How the Convention on International Trade in Endangered Species
(CITES) protects selected species:
|
| Regulation of sustainable exploitation |
Organisations that aim to exploit living resources sustainably:
|
Captive breeding and release programmes (CBR)
|
Content |
Additional information |
|---|---|
|
Ex-situ conservation is needed when conservation of species in their natural habitat is impossible or insufficient to protect the species. |
Reasons why keeping species in captivity may be difficult. |
| Methods of increasing breeding success |
|
| Soft and hard release programmes |
The selection of suitable release sites: Soft release. Hard release. Post-release monitoring. |
Habitat conservation
Content | Additional information |
|---|---|
In-situ conservation protects communities of species not just individual selected species. | |
| Habitat creation | New habitats may be created as a consequence of other human activities. New habitats may be created when wildlife conservation is the main aim.
Structural features of habitats may affect the success of conservation programmes:
|
| Management and conservation of habitats | Students should use a range of ecosystems and habitat areas to analyse their similarities and differences, especially the controlling ecological features and how this can inform conservation strategies. The importance of conservation should be related to the threats from human activities. |
Temperate broadleaf woodland Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
| |
Tropical rainforest Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
| |
Tropical coral reefs Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
| |
Deep-water coral reefs. Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
| |
Oceanic islands Features:
| |
Importance: endemic species. | |
Threats:
| |
Conservation efforts:
| |
Mangroves Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
| |
Antarctica Features:
| |
Importance:
| |
Threats:
| |
Conservation efforts:
|
The importance of ecological monitoring in conservation planning
|
Content |
Additional information |
|---|---|
|
It is important to identify the species present and features of their populations in planning conservation strategies. |
Population dynamics:
|
The development of new technologies for ecological monitoring
Students should understand how new technologies improve the validity of ecological research by allowing the collection of more representative data and new information.
|
Content |
Additional information |
|---|---|
|
New technologies used in ecological research |
(See Research methods) |
Life processes in the biosphere and conservation planning
How adaptation to the environment affects species’ habitat requirements and influences conservation decision-making
Students should be able to use examples of habitat management which benefit species that are adapted to particular abiotic and biotic factors. The deliberate provision of these conditions may increase species’ survival.
|
Content |
Additional information |
|---|---|
Abiotic factors:
|
|
Biotic factors:
|
Terminology to describe the roles of living organisms in their habitats and their interactions with the physical environment
Students should be able to use appropriate terminology to describe the roles of living organisms in their habitats and their interactions with the physical environment.
|
Content |
Additional information |
|---|---|
|
Ecological terminology |
|
The control of ecological succession in conserving plagioclimax habitats
Students should understand that many wildlife communities have developed in plagioclimax habitats maintained by long-term human activities. They should understand the processes in ecological succession that can inform conservation strategies.
|
Content |
Additional information |
|---|---|
|
Ecological succession |
|
|
Methods of maintaining plagioclimax communities:
|
How population control and the management of desired and undesired species affects the conservation of biodiversity
Students should understand the concept of carrying capacity and the influence of density and density-independent factors on regulating populations.
|
Content |
Additional information |
|---|---|
Management of desirable species:
|
|
| Control of undesirable species: culling/eradication. | |
|
r- and k- selection strategies and how they affect the ease with which species can be over-exploited. |
Opportunities for skills development and independent thinking
| Mathematical skill number | Opportunities for skills development and independent thinking |
|---|---|
| MS 0.2 | Students could use an appropriate number of decimal places in calculations, eg calculating mean population density from multiple sample sites in a habitat. |
| MS 0.3 | Students could calculate and compare percentage loss, eg of rain forests over a given time period of declining populations of endangered species. |
| MS 0.5 | Students should demonstrate their ability to interpret population growth curves. |
| MS 1.1 | Students could report calculations to an appropriate number of significant figures given raw data quoted to varying numbers of significant figures, eg in calculating indices of biodiversity. |
| MS 1.2 | Students could calculate mean population density from multiple quadrats. |
| MS 1.5 |
Students could compare and analyse data collected by random sampling and systematic, eg use Simpson’s index of diversity to compare the biodiversity of habitats with different management regimes. |
| MS 1.9 | Students could use Spearman's Rank Correlation Coefficient to analyse changes in abiotic and biotic factors with distance into a habitat, eg woodland. |
| MS 1.10 | Students should demonstrate their understanding of standard deviation as a useful measure of dispersion for a given set of data, eg for comparison with other data sets with different means such as populations of endangered species under different management regimes. |
| MS 1.11 | Students could calculate percentage error where there are uncertainties in measurement, eg estimating total population using sub-samples in a preliminary study. |
| MS 2.1 | Students could use = < << >> > when estimating maximum sustainable yield. |
| MS 2.3 | Students could use Simpson’s index of diversity to assess the impact of a new habitat management regime. |
| MS 3.1 | Students could construct a kite diagram of the change in population density of species along a transect. |
| MS 3.3 | Students could plot changes in species abundance with changes in abiotic factors eg temperature, water, pH. |
| MS 3.7 | Students could measure the gradient of a point on a curve, eg rate of population growth. |
| MS 4.1 | Students could calculate the circumference and area of nature reserves to assess the impact of the edge effect on wildlife conservation programmes. |
Working scientifically
Students could plan activities to investigate environmental issues which they could carry out eg:- population surveys in a habitat to be visited
- measurement of abiotic factors in a habitat to be visited.
- monitoring the impact of invasive species on indigenous species
- monitoring the impact of the local extinction of forest elephants on plant species with animal-dispersed seeds
- monitoring changes in population size, age structure and diversity after an area gains protected status, eg new MCZs
- monitoring the survival and dispersal of animals in captive breeding programmes after release
- estimating increases in biomass of tropical forests in response to increases in CO2 levels
- monitoring changes in water turbidity on coral reefs caused by land use changes, eg deforestation
- monitoring changes in penguin populations in Antarctica using satellite imagery
- monitoring the impact of fishing controls by the EU CFP on fish populations
- monitoring colonisation and changes in community composition in a recently created habitat.
| Practical skill number | Opportunities for skills development and independent thinking |
|---|---|
| PS 1.1 |
Students could assess the knowledge required to solve an environmental problem, eg:
|
| PS 1.2 |
Students could analyse existing knowledge and data eg:
|
| PS 1.3 |
Students could evaluate and explain the contribution that the results of the planned study would make to solving the problem eg:
|
| PS 1.4 | Students could plan studies to gain representative, reliable data, using the selected methodologies and sampling techniques below. |
| PS 2.1 | Students could evaluate the methods of previous studies and analyse the reliability of the data produced. |
| PS 2.2 |
Students could analyse their method and the results produced to identify limitations in the method and any inaccuracies in results eg:
|
| PS 2.3 |
Students could identify the other variables that could also affect their results eg: in a study of the effect of light levels on ground flora: soil pH, temperature, humidity, wind velocity. In a study of increased forest biomass caused by rising CO2 levels: changes in water availability, temperature and forest management. |
| PS 2.4 |
Students could use a variety of methods to present data:
|
| PS 3.1 | Students could construct line graphs to show changes in data over time or correlations between variables. |
| PS 3.2 | Students could use data on species richness and abundance to calculate Simpson’s Index of diversity. |
| PS 3.3 | Students could compare estimates of population size for the same habitat produced by different groups to consider possible causes of the variation. |
| PS 4.1 | The practical skills of using equipment within scientific environmental studies are expanded in the selected methodologies and sampling techniques below. |
Opportunities to investigate the required methodologies of which students must have first hand experience. Further details can be found in Appendix A: Working scientifically
| Methodology skill number | Opportunities for skills development and independent thinking |
|---|---|
| Me 1 |
Students could plan the collection of samples using random sampling. Eg: Ground flora in woodland or grasslands. |
| Me 2 |
Students could plan the collection of samples using systematic sampling eg:
|
| Me 3 |
Students could carry out a preliminary study and analyse the results to assess the smallest number of samples that produce reliable results eg: Using increasing numbers of quadrats to estimate the total population. Eg estimating total population using mean values from 5, 10, 25, 50, 100 etc quadrats. The reduction in fluctuations in overall mean values will enable students to select an appropriate sample number for further studies. |
| Me 4 |
Students could carry out a preliminary study and analyse the results to assess the smallest sample size that produces reliable results. eg: estimating lichen percentage cover on bark using increasing sizes of sample area. The minimum size is that where using larger areas does not cause the value to change significantly and reliability to increase. |
| Me 5 |
Students could identify appropriate timings for surveys to be carried out eg:
|
| Me 6 |
Students could carry out statistical tests to assess the significance of the data eg: Spearman’s Rank Correlation Coefficient for abundance of a species and an abiotic factor along a transect. |
Opportunities to investigate the required sampling techniques of which students must have first hand experience. Further details can be found in Appendix A: Working scientifically
| Sampling technique skill number | Opportunities for skills development and independent thinking |
|---|---|
| ST 1 |
Students could analyse the effect of wind velocity or temperature on the activity of bats or moths to consider the possible impacts of climate change. |
| ST 2 | Students could compare plant biodiversity in grasslands with different mowing regimes. |
| ST 5 | Students could use a Tüllgren funnel to compare the invertebrates in the leaf litter of two different woodlands. |
| ST 6 | Students could use kick sampling to compare invertebrate diversity in different streams or areas of the same stream with different substrates. |
