3.3, 3.4: Biodiversity and Conservation

3.3 - Threats to Biodiversity

• Estimates of the total number of species vary considerably

  • Most are animals and most are terrestrial
  • ⅔ rds are in the tropics, mostly tropical rainforests
  • 50% of tropical rainforests have been cleaned by humans

• When nearly all that habitat goes, extinction rates increase rapidly

  • current rates of species loss = greater than the past due to increased human influence
  • extinction can be caused by human activities, such as: habitat destruction, invasive species, pollution, overharvesting, haunting

• Factors maintaining biodiversity:

  • complexity of the ecosystem: the more complex a system is, the more resilient its species will be
  • stage of succession: older, more resilient and stable ecosystems which undergo succession are less vulnerable than in young ecosystems
  • limiting factors: changes to materials provided will make it harder and result in species disappearing system is more likely to manage it one of abiotic factors is reduced
  • Inertia: property of an ecosystem to resist when subjected to a disruptive force

• Factors which lead to loss of biodiversity:

  • Natural hazards: naturally occurring events that may have a negative impact on the environment and humans
  • are considered natural disasters when the impact worsens
  • major cause of loss of biodiversity = loss of habitat

• Fragmentation of habitat: the process where a large area is divided up into patchwork of fragments

  • separated from each other by roads, towns, factories, fences

• Pollution: caused by humans can degrade or destroy habitats and make them unsuitable to support the range of species

  • local pollution, environmental pollution, eutrophication, climate change which alters weather patterns and shifts biomes

• Overexploitation: has escalated as human populations expand

• Introducing non-native species → can upset a natural ecosystem

• Spread of a disease → decrease biodiversity

• Modern agricultural practices: can reduce diversity with monocultures, genetic engineering and pesticides

• Vulnerability of tropical rainforests:

  • Tropical biomes: contain some of the most globally biodiverse areas in their unsustainable exploitation results in massive losses in biodiversity and their ability to perform globally impotent ecological services
  • most tropical biomes occur in less economically developed countries and there is conflict between exploitation and sustainable development and conservation

• International Union for conservation of nature (IUNC): published the red list of threatened species in several categories

  1. Extinct (EX): inability to record an organism, all individuals are dead
  2. Extinct in the wild (EW): captivity as a naturalised species outside past range
  3. Critically end (CE): considered to be in extremely high risk of extinction
  4. Vulnerable (VU): high risk of extinction
  5. Near threatened (NT): close to qualifying for one of the threatened once in the category
  6. Not evaluated (NE): not evaluated against the criteria

3.4 - Conservation to Biodiversity

• Diversity of species: in the ecosystem promotes healthy and good environment

  • extinction = normal
  • A community thrives when species evolve and adapt to changes, every species has its own ecological importance

• Why should we conserve biodiversity?

  • Direct value: food species, natural products
  • Indirect value: human rights, environmental services, scientific education values, human health, and ecocentrism

• Conservation biology: sustainable use and management if natural resources

• Preservation biology: attempts to exclude human activity in areas where humans have not yet encroached

• Conservation → protect natural resources and proper use of nature

  • Use water from water sources such as lakes

• Preservation → protect what has been built from resources and protection of nature from use

  • From water sources such as cleaning and washing

• Organisations of biodiversity conservation:

  • IGO (intergovernmental organisation): composed of different groups from different countries
  • Governmental organisations (GO’s): composed of groups funded by a national government
  • Non-governmental organisation (NGO): composed of groups run by volunteers, no relation to governments non-profit

• Approaches to conservation:

  1. CITES (conservation pn the international trade in endangered species):
  • Appendix 1: species cannot be traded internationally as they are threatened with extinction
  • Appendix 2: species can be traded internationally but with strict regulations to ensure sustainably
  • Appendix 3: a species included at the request of a country which needs help of other countries to prevent illegal exploitation
  1. Captive breeding and zoos:
  • Holding and caring for species in captivity for research and maintenance of species
  • Maltreatment and poor habitats of reserves and zoos
  • Reintroduction of species does not guarantee survival and may cause a loss of money
  1. Botanical gardens and seed banks:
  • Protection and cultivation of different species whether common or rare
  • Some plants need extra care or technology to grow and survive
  1. Flagship species:
  • Prioritised over other species
  • Most common species and known worldwide
  • If they become extinct, we failed to take care of them
  1. Keystone species:
  • Species that are considered to have a critical role in maintaining the structure of the ecosystem

• Designing protected areas: where a conservation area is within a country is a significant factor in the success of the conservation effort

  • Surrounding areas including land formations and urban areas
  • Location in a remote area where people don't usually live
  • high biodiversity
  • low population density