Topic 3: Biodiversity and conservation

• Total diversity of living systems • Habitat diversity, species diversity, genetic diversity

• Components of diversity contribute to ecological system resilience

• Cumulative change in heritable characteristics

• Mechanism driving evolutionary change • Operates continuously over billions of years

• Variation, overproduction, competition for limited resources • Differences in adaptation affect survival and reproduction rates • Heritable variation → increased frequency of advantageous genes

• Generation of new species through evolution • Population isolation → adaptation → inability to interbreed

• Richness: number of species in community • Evenness: similarity of population sizes

• Quantitative measure of species diversity • Allows ecosystem comparison and monitoring change over time

• Knowledge of global and regional biodiversity is needed for the development of effective management strategies to conserve biodiversity • Include: how knowledge of biodiversity is gathered in the local region • This is likely to involve citizen science and the work of voluntary and government-funded agencies • The training of indigenous people and others, such as parabiologists, is also used to gather information for use in conservation management

3.2.1Threats to biodiversity

• Direct: overharvesting, poaching, illegal pet trade • Indirect: habitat loss, climate change, pollution, invasive alien species

3.2.2Multiple human impacts

• Most ecosystems subject to multiple impacts • Effects amplified when combined

3.2.3Invasive alien species

• Reduce biodiversity through competition, predation, diseases/parasites

3.2.4IUCN Red List

• Global conservation status assessment • Based on: population numbers, rate changes, breeding potential, geographic range, threats • Status ranks: least concern (LC) to extinct (EX)

3.2.5Conservation status benefits

• Publicizes species vulnerability • Allows selection of conservation priorities and management strategies

3.2.6Species case studies

• Extinct species due to human activity • Critically endangered species • Species improved by intervention

3.2.7Tragedy of the commons

• Overexploitation of shared natural resources • Tension between individual self-interest and sustainable development • Examples: fish stocks, ocean plastic pollution

• Aesthetic, ecological, economic, ethical, social

• Species-based: ex situ (zoos, botanic gardens, CITES, seed banks) • Habitat-based: in situ (national parks, reserves, sanctuaries)

• Both habitat and particular species considered • Flagship/keystone species used to justify habitat conservation

• UN treaty addressing species and habitat conservation • National strategies for conservation and sustainable use • Includes Nagoya Protocol (equitable sharing of genetic resources)

• Protect species by conserving natural environment • May require wild area protection or active management

• Understanding target species biology • Size and shape of conservation areas • Edge effects, wildlife corridors for connectivity • UNESCO biosphere reserves: pristine core, buffer zones, transition zones

• Regenerates natural processes in ecosystems • Methods: apex predator reintroduction, habitat connectivity, cessation of agriculture

• Reverse biodiversity decline • Operating within biodiversity planetary boundary • Individual, collective, national, international levels

• Environmental perspectives and value systems impact choices • Success depends on: community support, funding, education, legislation, research