L1 - biodiversity

• Individual: single member of a species
• Population: individuals of the same species in the same area at the same time
• Community: multiple populations of different species living and interacting in the same area
• Ecosystem: interaction between a community and the non living (abiotic) parts of the environment
• Biotic: living factors that affect organisms in an ecosystem
• Abiotic: non living factors that affect organisms in an ecosystem
• Habitat: the place where an organism lives, providing the conditions it need to survive
• Species: a group of similar organisms that can breed together to produce fertile offspring
• Niche: the role of a species within an ecosystem, including its interactions with biotic and abiotic factors
• Biodiversity: the variety of different species in an ecosystem
• Three levels of diversity:

  -genetic diversity

  -species diversity

  -ecosystem diversity
• Habitat/ecosystem diversity:

  -the range of different ecosystems or habitats within a particular area

  -if there are many different habitats within an area, then that area has a high level of biodiversity
• Species diversity:

  -looks at the number of different species in a community (species richness), and also the evenness of abundance across the different species present (species evenness)
• Species richness: the number of species within a particular area

  -the higher the species richness the higher the diversity
• Species evenness: a comparison of the number of individuals of each species

  -an area in which all the species have similar abundances will have a greater species evenness
• We can calculate species diversity using the Sampson’s Index: $D=$$1-\left(\Sigma\left(\frac{n}{N}\right)^2\right)$

  -n is the number of organisms of each species

  -N is the total number of organisms
• Genetic diversity: the variety of genetic material (alleles) present in a species or population