Topic 3

• Biodiversity


  The total diversity of living systems. This includes the diversity of species, habitat diversity and genetic diversity.
• Species diversity


  Species diversity in communities is a product of two variables: the number of species (richness) and their relative proportions (evenness).
• Habitat diversity


  Habitat diversity refers to the range of different habitats in an ecosystem or biome.
• Genetic diversity


  Genetic diversity refers to the range of genetic material present in a population of a species.
• Endemic


  native or restricted to a particular area

  e.g. the Bali Starling is found only on the island of Bali. It is endemic to Bali. It is a Bali endemic species.
• Evolution


  is a gradual change in the genetic character of populations over many generations, achieved largely through the mechanism of natural selection
• natural selection


  is an evolutionary driving force, sometimes called "survival of the fittest". In this context, the meaning of "fitness" is understood to be "best-suited to the niche"
• Natural Selection stages


  1) Variation exists and there is overproduction so competition for resources; 2) Some individuals are thus fitter than others; 3) Fitter individuals reproduce more successfully; 4) Offspring inherit genes that give advantage
• Speciation


  the formation of new species when populations of a species become isolated and evolve differently from other populations.
• Isolation of populations: Causes

  barriers such as mountain formation; changes in rivers, sea level change, climatic change or plate movements
• Plate tectonics


  the surface of the Earth is divided into crustal, tectonic plates, that have moved throughout geological time. This has led to the creation of both land bridges and physical barriers with evolutionary consequences.
• Mass extinction causes


  tectonic plate movements, super-volcanic eruption, climatic changes (including drought and ice ages), and meteorite impact
• Biogeography


  the study of the distribution of species and their evolution in relation to geographical distribution
• disjunct distribution


  when one species or sister species are distributed in two very different locations, e.g. New Zealand and Chile
• plume


  location where a column of magma rises up to the surface - not associated with a plate boundary
• core


  the centre of the earth
• mantle


  molten rock between the core and the crust of the Earth's surface
• Aesphenosphere


  the upper part of the mantle - acts like a molten plastic
• Crust


  the cooled rock that floats on the mantle - divided into plates
• palaeontology


  the study of fossils
• geomorphology


  the study of the shapes of the Earth's surface
• ratites


  ostrich like birds that share a common ancestor, including, rhea, emu, kiwi, cassowary and extinct elephant birds and moa.
• adaptive radiation

  a group of closely related species that have rapidly evolved from one common ancestor, usually on islands where empty niches exist
• biodiversity hotspot

  biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction.
• invasive species

  a species not native to an area which is causing a problem to local species
• Human Activities Causing Species Extinctions

  habitat destruction, introduction of invasive species, pollution, overharvesting, hunting and climate change
• Factors for Red List

  population size, degree of specialisation, distribution, reproductive potential and behaviour, geographic range and degree of fragmentation, quality of habitat, trophic level, probability of extinction
• extinct

  no longer survives on Earth
• extinct in the wild

  only survives in zoos or botanic gardens
• Threatened

  umbrella term for Critically Endangered, Endangered and Vulnerable species
• Causes of Tropical Deforestation

  Over-intensive shifting cultivation; Timber extraction; Over-collection of fuelwood for cooking and heating, and for making charcoal;

  Encroachment and clearance by landless peasant farmers; Clearance for pasture or crops, promoted by cheap land and government tax and financial incentives to encourage international investment - this includes Biofuels like Palm Oil and Sugar Cane
• Species and Habitat preservation arguments

  aesthetic. ecological, economic, ethical, social reasons
• Governmental Organisations (in conservation)

  eg UNEP United Nations Environment Programme
• Non-governmental organisations (NGOs) (In conservation)

  International - WWF or Greenpeace; community based e.g. Palani Hills Conservation Council or Vatakanal Trust
• Comparing effectiveness of Conservation Organisations

  Use of media, speed of response, diplomatic constraints, financial resources, political influence
• Convention on Biological Diversity (CBD)

  First signed in Rio at Earth Summit (1992) and uses an ecosystem approach (an integrated strategy for the management of resources)
• precautionary principle

  where there is a threat of significant reduction or loss of biological diversity, lack of full scientific certainty should not be used as a reason for postponing measures to avoid or minimize such a threat
• National Biodiversity Strategy and Action Plan (NBSAP)

  Strategy is how a country intends to fulfill the objectives of the CBD, while the National Biodiversity Action Plan comprises the concrete actions to be taken to achieve the goals of the strategy
• 2010 Biodiversity Convention

  To achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on Earth.
• Conservation Approaches

  Habitat conservation, species conservation or a mixed approach