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Biodiversity, Habitat Loss and Fragmentation. SNC 1D ECOLOGY UNIT. The importance of biodiversity. Biodiversity is the variety of life found in an area. Species richness is the number of species found in an area. An area with a higher biodiversity will have a greater species richness.
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Biodiversity, Habitat Loss and Fragmentation SNC 1D ECOLOGY UNIT
The importance of biodiversity • Biodiversity is the variety of life found in an area. Species richness is the number of species found in an area. An area with a higher biodiversity will have a greater species richness. • Tropical Rainforest Biodiversity Video: • http://www.youtube.com/watch?v=275bxGiHrVM
Causes of loss of biodiversity • Deforestation • Urban and agricultural expansion • Pollution • Climate change • Invasive species • Fishing • Hunting • Overconsumption of resources/population growth
Species who are extinct (no longer exist on Earth) • Extinction is natural process, but humans are increasing rate of extinction • Examples of extinct species: passenger pigeon, Dodo bird, Tasmanian tiger, Saber-toothed tiger
Extinction rate increasing • http://www.youtube.com/watch?v=p0aHPeqg2zI
Categories of Species at Risk • http://www.youtube.com/watch?v=EInws8p9lWU • In your handout, you should write in examples for each category of species at risk.
Factors that enhance sustainability of habitat fragments • 1. Size -larger fragments support larger and more stable populations and communities
Factors that enhance sustainability of habitat fragments • 2. number • One large area is better than an equal area composed of many smaller areas (less outside influence)
Factors that enhance sustainability of habitat fragments • 3. Proximity • When ecosystem fragments are closer to each other, there is a better chance the populations will be able to use the whole area
Factors that enhance sustainability of habitat fragments • 4. Connectedness • Areas that are connected allow for wildlife to migrate between these blocks
Factors that enhance sustainability of habitat fragments • 5. Integrity • It is better if ecosystem not disrupted by roads or trails since these can create more pollution, hunting and fishing
Threats to Sustainability • Habitat loss and fragmentation are second to climate change as the most serious threat to sustainability of terrestrial ecosystems
Loss of wetlands and aquatic ecosystems • Read p. 90 and take notes under each sub-heading with regards to impact of each human activity on wetland and aquatic ecosystems
Assessing your understanding • Which ecosystem has the highest biodiversity? • What do we call it when a single large and continuous natural area is separated into smaller patches? • A species that may becomes or threatened or endangered is called __________________.
Assessing your understanding • A species likely to become endangered if factors do not change is _____________. • A species that no longer exists is called ___________. • A species facing imminent extinction is called ___________________.
Assessing your understanding • Which type of habitat fragment is better for sustainability: those that are closer together or farther apart? Explain.