Tundra

• Permafrost/glaciers in tundra provide important storage in hydrological cycle 1 mark
• Ice in tundra provides reflective surface/increases planetary albedo, thus moderating global temperatures 1 mark

Wetlands

• Decomposers/high productivity in swamps/wetlands provides filtration of inorganic nutrients / water purification 1 mark
• Storage of water in wetlands prevents flooding / provides ideal resting grounds for migratory birds 1 mark

Tropical rainforests

• High biodiversity in tropical rainforests promotes ecotourism/recreation 1 mark
• High rate of photosynthesis in tropical rainforests maintains balance of O2/CO2 in atmosphere 1 mark

Boreal/temperate forests

• Tree populations in boreal/temperate forests prevent soil erosion on mountainsides 1 mark
• Forest canopies in forests provide shade/shelter/habitat for diversity of species 1 mark

Be careful only to credit "services" (maintenance/establishment of favourable conditions) and not "goods" (consumable/harvestable/physical products).

Award [2 max] if no biome is identified. If more than one biome is given, credit only highest scoring biome addressed.

Causes 3 max

• Habitat loss / deforestation
• Habitat degradation / pollution
• Narrowly distributed / endemic
• Poaching / overhunting
• Illegal trafficking of species
• Disease
• Small population size/gene pool / inbreeding
• Specialised niche
• Slow reproduction rate / specialised reproductive behaviour
• High trophic level/top predator
• Low/negative cultural value
• Influence/competition/predation from invasive species

Consequences 3 max

• Loss of an aesthetically attractive organism
• Loss of ethically significant life / breach of biorights
• Loss of biodiversity
• Increase in organisms upon which the species fed or competed with
• Decline in other organisms due to loss of food source
• If keystone species, widespread impacts/cascade effects on food chains/ecosystem
• Economic costs from loss of ecosystem services provided by the species
• Economic costs from loss of tourism opportunities
• Social impacts on local culture as important/significant cultural loss

Max. 4 marks without explaination

Answers may include:

• Habitat conservation aims to protect entire ecosystems and the various species within them, while a species-based approach focuses on specific threatened species.
• Protects multiple species and their interactions within an ecosystem
• Addresses root causes of biodiversity loss like habitat destruction and fragmentation
• Maintains ecosystem services like water purification, nutrient cycling, and climate regulation
• Examples: Establishing protected areas, restoring degraded habitats, sustainable forestry practices
• Targets critically endangered species at high risk of extinction
• Allows for focused efforts on specific species' needs and threats
• Examples: Captive breeding programs, reintroduction efforts, anti-poaching measures

Marks	Level descriptor
0	The response does not reach a standard described by the descriptors below and is not relevant to the question.
1–3	The response contains:• minimal evidence of knowledge and understanding of ESS issues or concepts • fragmented knowledge statements poorly linked to the context of the question • some appropriate use of ESS terminology • no examples where required, or examples with insufficient explanation/relevance • superficial analysis that amounts to no more than a list of facts/ideas • judgments/conclusions that are vague or not supported by evidence/argument.
4–6	The response contains: • some evidence of sound knowledge and understanding of ESS issues and concepts • knowledge statements effectively linked to the context of the question • largely appropriate use of ESS terminology • some use of relevant examples where required, but with limited explanation • clear analysis that shows a degree of balance • some clear judgments/conclusions, supported by limited evidence/arguments.
7–9	The response contains: • substantial evidence of sound knowledge and understanding of ESS issues and concepts • a wide breadth of knowledge statements effectively linked with each other, and to the context of the question • consistently appropriate and precise use of ESS terminology • effective use of pertinent, well-explained examples, where required, showing some originality • thorough, well-balanced, insightful analysis • explicit judgments/conclusions that are well-supported by evidence/arguments and that include some critical reflection.