Topic 3 Biodiversity and Conservation

At the end of this subtopic 3.1 you should understand:

• Biodiversity is the total diversity of living systems and it exists at several levels. (3.1.1)

• The components of diversity contribute to the resilience of ecological systems. (3.1.2)

• Knowledge of global and regional biodiversity is essential for the development of effective management strategies to conserve biodiversity. (3.1.9)

• Biodiversity arises from evolutionary processes. (3.1.3)

• Natural selection is the mechanism driving evolutionary change. (3.1.4)

• Evolution by natural selection involves variation, overproduction, competition for limited resources, and differences in adaptation that affect rates of survival and reproduction. (3.1.5)

• Speciation is the generation of new species through evolution. (3.1.6) 

• Species diversity in communities is a product of richness and evenness. (3.1.7)

• Simpson's Reciprocal Index is used to provide a quantitative measure of species diversity, allowing comparisons of different ecosystems,  and monitoring of change in specific ecosystems over time to be monitored. (3.1.8)

At the end of this subtopic 3.2 you should understand:

• Biological diversity is being adversely affected by both direct and indirect influences. (3.2.1)

• Most ecosystems are subject to multiple human impacts. (3.2.2)

• Invasive alien species can reduce local biodiversity by competing for limited resources, predation, and introduction of diseases or parasites. (3.2.3)

• The tragedy of the commons describes possible outcomes of the shared unrestricted use of a resource, with implications for sustainability and the impacts on biodiversity. (3.2.7)

• The global conservation status of species is assessed by the International Union for Conservation of Nature (IUCN) and is published as the IUCN Red List. Status is based on number of individuals, rate of increase or decrease of the population, breeding potential, geographic range, and known threats. (3.2.4)

• Assigning a global conservation status publicises the vulnerability of species and allows governments, non-governmental agencies, and individual citizens to select appropriate conservation priorities and management strategies. (3.2.5)

• Investigating three different named species: a species that has become extinct due to human activity; a species that is critically endangered; and a species whose conservation status has been improved by intervention. (3.2.6)

At the end of this subtopic 3.3 you should understand:

• Arguments for species and habitat preservation can be based on aesthetic, ecological, economic, ethical, and social justifications. (3.3.1)

• Conservation and regeneration measures can be used to reverse the decline in biodiversity to ensure a safe operating space for humanity within the biodiversity planetary boundary. (3.3.8)

• The Convention on Biological Diversity (CBD) is a UN treaty addressing both species-based and habitat-based conservation. (3.3.4)

• Environmental perspectives and value systems can impact the choice of conservation strategies selected by a society. (3.3.9)

• Species-based conservation tends to involve ex situ strategies, and habitat-based conservation tends to involve in situ strategies. (3.3.2)

• Habitat conservation strategies protect species by conservation of their natural environment. This may require protection of wild areas or active management. (3.3.5)

• Effective conservation of biodiversity in nature reserves and national parks depends on an understanding of the biology of target species and on the effect of the size and shape of conservation areas. (3.3.6)

• Sometimes a mixed conservation approach is adopted, where both habitat and particular species are considered. (3.3.3)

• Natural processes in ecosystems can be regenerated by rewilding. (3.3.7)