4.2 Why is biodiversity important? What are the outcomes of diversity loss?

TASK: Class brainstorm – In what ways is our College diverse? What is homogeneity and heterogeneity and how can you connect these terms to diversity?

Key words: diversity, biodiversity, habitat diversity, species diversity, genetic diversity

Case Study starter: Singapore’s Profile – Convention on Biological Diversity

TASK: Research two contrasting Biodiversity Hotspots using Conservation International org. and the Encyclopedia of Earth (EoE).Screen Shot 2014-04-22 at 9.45.02 am

CASE STUDY: TRF SEA – Sundaland Biodiversity Hotspot & Endemics

Everything you ever wanted to know about Sundaland… and more – click here (EoE)

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QUESTION: What are the ecological changes that may result in the loss of species in the Sundaland Hotspot?

1. Forest habitat destruction:

  • rubber production, pulp production, and commercial and illegal logging.
  • Palm oil plantations. Increasing prices for palm oil led the government of Jambi Province, in Sumatra, to plan for the conversion of one million hectares of forest to palm oil.
  • Rapid road construction increases the extent and speed of deforestation, by providing access for loggers, settlers and miners. (fragmentation)
  • commercial and illegal logging – extensive in some protected areas e.g. Bukit Barisan Selatan and Gunung Palung national parks
  • Fires – logging operations create flammable conditions by leaving fuelwood on the forest floor and by exposing the understory to drying. Fires are also sometimes intentionally lit to convert forests to oil palm plantations. Because few tropical plants are adapted to periodic fires, tropical forests are very slow to regenerate after burning.
  • Today, only around 700,000 km2 of forest remains, much of it highly fragmented. Only about 100,000 kmremains in more or less intact condition – only seven percent of the original extent of the forest.

2. Wildlife trade:

  • Orangutans (e.g. Sumatran Pongo Abelii) numbers were severely reduced in the past because of the pet trade.
  • tigers and rhinoceroses are the most visible targets of hunting for the Chinese medicine market, for skins, body parts, and horns.
  • Turtles, snakes, geckos, pangolins, bears, and monkeys are exported by the ton from the region on a daily basis.
  • Indonesia – leading producer and exporter of snake leather
  • export of live turtles to East Asia. Most turtle populations are either in decline or have collapsed.
  • massive cage-bird trade has also placed a number of species (e.g. Bali Starling) under serious threat.

Five Historical Mass Extinctions

There has been a rapid increase in extinction rates as a result of human activity. Scientists estimate that human destruction of natural habitat is driving up to 100 000 species to extinction every year. This recent acceleration in species loss is sometimes called the sixth extinction.

Five mass extinctions in order of oldest to most recent… These are the names of geologic time periods when mass-extinctions have taken place.

  1. Ordovician
  2. Devonian
  3. Permian
  4. Triassic
  5. Tertiary
  6. A Modern Mass Extinction?


What the skeptics are saying? Click Mass Extinction Controverse for further information.

TASK: Why do species become extinct? How can humans intervene to prevent extinction of a species? Use the shared google doc table (class site) to complete your work.

Global warming and species’ abilities to adapt to their ‘new’ environments…  Click on the  title below to read a great article from National Geographic (thank you Fumika for sharing the link!)

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Review – Can you:

  • Identify factors that lead to loss of diversity?
  • Discuss the perceived vulnerability of tropical rainforests and their relative value in contributing to global biodiversity?
  • Why is tropical rainforest biodiversity important of global importance and how does it bring stability?
  • What happens when biodiversity is lost?

Looking for a bit of topical reading? Here’s a good web resource on ecological services and sustainable use of ecosystem resources – have a browse: Millennium Ecosystem Assessment from 2001-2005.


THINKING AHEAD: (Topic 3) – How does Global Warming threaten biodiversity? In what ways can you link Global Warming and mass extinctions?

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