• Biodiversity includes the diversity of species, habitat, and genes:
  • Species diversity involves both the variety/number of species (richness) and their relative proportions (evenness) 1 mark
  • Habitat diversity refers to the range of different habitats in an ecosystem or biome, which may vary due to environmental gradients/changing abiotic conditions/altitude/latitude/major disturbances (volcanic activity/landslides, etc.) 1 mark
  • Habitat/niche diversification promotes species diversity 1 mark
  • Genetic diversity refers to the range of genetic material/genes in a population/species, influenced by mutation/sexual reproduction/natural selection/speciation 1 mark
• Succession promotes greater biodiversity by increasing length/branching of food chains / because it leads to improved abiotic conditions

Credit can be gained through description of particular ecosystems e.g. climax communities; hotspots; but the specific factors must be identified to gain credit.
Do not credit human impacts or any factor reducing biodiversity.

Ecological techniques to study human impact on biodiversity

• Quadrat/transect sampling 1 mark

  • Used to estimate population size/density of species
  • Compare disturbed vs undisturbed areas to assess impact

• Species richness indices (e.g. Simpson's, Shannon-Wiener) 1 mark

  • Calculate from sample data to quantify species diversity
  • Compare indices between sites to evaluate human impact

• Mark-release-recapture 1 mark

  • Estimate population size of mobile species
  • Assess impact of habitat loss/fragmentation

• Bioindicators/biomonitors 1 mark

  • Presence/absence of sensitive species indicates level of disturbance
  • Monitor changes over time to assess recovery/further degradation

• GIS mapping/remote sensing 1 mark

  • Map habitat loss/fragmentation due to human activities
  • Correlate with biodiversity data to evaluate impact

• Environmental DNA (eDNA) sampling 1 mark

  • Detect species from trace DNA in soil/water samples
  • Assess biodiversity without direct observation/capture

Describe how the technique is used and link explicitly to assessing human impacts on biodiversity.

Answers may include:

• understanding concepts and terminology of the roles of organizations in conserving and restoring ecosystems and biodiversity; roles of international conventions on biodiversity; role of IUCN and Red List; CITES; captive breeding and reintroduction programmes; zoos, botanical gardens and seed banks; role of charismatic/flagship species vs keystone species; design of protected areas and impact of community involvement; genetic/species/habitat diversity; threats to biodiversity; impact of extinction/biodiversity loss; strategy approach depending on EVS; habitat vs species vs mixed approach;etc;
• breadth in addressing and linking a range of strategies for conservation to their relative success in addressing biodiversity as measured by a range of criteria (including measures of biodiversity; costs; resilience of systems; public popularity/engagement; rarity of protected species/habitats; etc;)
• examples can include a range of specific conservation measures / protected areas/zoos / means of assessing success / case-studies.
• balanced analysis of the extent to which conservation has or has not been successful in conserving biodiversity.
• a conclusion that is consistent with, and supported by, analysis and examples given eg 'there are individual success stories, such as the observed increase in panda populations in Western China or increased counts of the tiger in India, and these are associated with increases in biodiversity to support these species, but the overall trend in biodiversity is down with massive percentages of species threatened by habitat degradation and climate change';