Topic 3: Biodiversity and conservation

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  1. 3.1 Biodiversity and evolution

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

    2. • Components of diversity contribute to ecological system resilience

    3. • Cumulative change in heritable characteristics

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

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

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

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

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

    9. • 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

  2. 3.2 Human impact on biodiversity

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

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

    3. • Reduce biodiversity through competition, predation, diseases/parasites

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

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

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

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

  3. 3.3 Conservation and regeneration

    1. 3.3.1Preservation justifications

      • Aesthetic, ecological, economic, ethical, social

    2. 3.3.2Conservation strategies

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

    3. 3.3.3Mixed conservation approach

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

    4. 3.3.4Convention on Biological Diversity (CBD)

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

    5. 3.3.5Habitat conservation strategies

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

    6. 3.3.6Effective conservation factors

      • 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

    7. 3.3.7Rewilding

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

    8. 3.3.8Conservation measures

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

    9. 3.3.9Perspectives and conservation strategy choice

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