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Biodiversity and Human Population Growth


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This contains a powerpoint lecture (41 slides) on how human population growth affects biodiversity and endangered species.

Published in: Business, Technology
  • @princessmaria90038882 nope it's not a myth, over a billion ppl is overpopulation unlike 5 centuries ago human populations were being killed off from disease and lifespans were shorter due to drought and starvation, now a days there's vaccines that control disease and and techniques for droughts and famines, outbreaks which contributes to how homo sapiens is overpopulating the earth,
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  • over population is a myth
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  • interesting indeed
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Biodiversity and Human Population Growth

  1. 1. Human Population Growth and the Problem of Biodiversity <ul><li>Human population has increased at an almost exponential rate. </li></ul><ul><li>With this growth comes an increase in demand for land, food, water, energy and other resources. </li></ul><ul><li>As human numbers grow species and their habitat diminish. </li></ul>
  2. 3. Biodiversity <ul><li>Biodiversity is the variety of all forms of life throughout an ecosystem. </li></ul><ul><li>High rates of extinction are quickly reducing biodiversity especially in areas of the world with high human population density and growth. </li></ul><ul><li>The direct and indirect effects that humans have had on biodiversity is challenging as can be seen from the following flow chart. </li></ul>
  3. 4. Human Population Size Resources use Land Transformation Land Clearing Forestry Grazing Intensification Biotic Additions and Loss Invasion Hunting Fishing Carbon Nitrogen Water Climate Change Enhanced Greenhouse Aerosols Land cover Loss of Biological Diversity Extinction of species And populations Loss of ecosystems Vitousek et. al (1997) Science, 277, p.494-499 Human Enterprises Agriculture Industry Recreation International Commerce Global Biogeochemistry
  4. 5. Humans Change of the Earth Expressed as % Change Vitousek et. al (1997) Science, 277, p.494-499
  5. 6. Biodiversity and People <ul><li>Places on earth with some of the greatest biodiversity such as: South America, Equatorial Africa, India, Indonesia and Coastal regions also show the greatest density and fastest rate of growth of people. </li></ul><ul><li> </li></ul>
  6. 7. Biodiversity
  7. 8. World Population
  8. 9. Extinction <ul><li>Extinction is the natural order. In fact, of all the species which have ever existed, 99.9 % are now extinct! </li></ul><ul><li>The current extinction rates, however, may be as much as 40 - 100 times the normal “background” or natural rate for extinction. </li></ul>
  9. 10. Extinction <ul><li>Paul Ralph Ehrlich at Stanford University predicts that soon, this rate may be as much as 400 times the &quot;normal&quot;, average, rate of extinction! </li></ul><ul><li>Much of this increase in extinction rate appears to be due to the impact of humans. </li></ul><ul><ul><li>Habitat Depletion </li></ul></ul><ul><ul><li>Pollution </li></ul></ul><ul><ul><li>Introduction of disease </li></ul></ul><ul><ul><li>Introduction of invasive species </li></ul></ul><ul><ul><li>Over exploitation </li></ul></ul>
  10. 11. Extinction <ul><li>25% of the earth’s birds species have been driven to extinction by humans (especially on islands). </li></ul><ul><li>Threatened with Extinction </li></ul><ul><ul><li>11% of birds </li></ul></ul><ul><ul><li>18% of mammals </li></ul></ul><ul><ul><li>5% of fish </li></ul></ul><ul><ul><li>8% of plants </li></ul></ul>Great Auk
  11. 12. Loss of birds
  12. 13. Extinction Rate
  13. 16. The Oceans and the Coast <ul><li>Globally, the number of people living within 100 km of the coast increased from roughly 2 billion in 1990 to 2.2 billion in 1995 (39 percent of the world's population). </li></ul>
  14. 17. Coastal Area Population Density <ul><li>3.2 Billion (1/2 of the plant) live and work within 125 miles from a coastline. </li></ul><ul><li>4 Billion (2/3) live within 250 miles from the coast. </li></ul>
  15. 18. Coastline, Estuaries and Reefs <ul><li>While 75% of the earth is covered by oceans, the greatest levels of marine biodiversity are found near the coast. </li></ul><ul><li>This Neritic zone of the ocean has depth of less than 250 meters and so the abundant photosynthetic organisms create a habitat for great biodiversity. </li></ul>
  16. 20. Kelp Forest Near Monterey California
  17. 21. Approximately 50% of mangrove ecosystems globally have been transformed or destroyed by human activity
  18. 22. Great Barrier Reef, Australia
  19. 23. Human causes of Coral Reefs Depletions <ul><li>Pollution runoff : nitrates from fertilizers, point-source pollution, oil spills. </li></ul><ul><li>Exploitation : Over 90% of saltwater aquarium fish are taken directly from reefs. </li></ul><ul><li>Increased water temperatures : global warming, increased El Nino. </li></ul><ul><li>Direct Destruction : Boats, fishing nets, removal of coral for sale. </li></ul>
  20. 24. Coastline and Reefs <ul><li>“ With increased human population and improved storage and transport systems, the scale of human impacts on reefs has grown exponentially.” </li></ul><ul><li>Dr. Terry Hughes Scientific Director of the Centre for Coral Reef Biodiversity at James Cook University in Queensland, Australia </li></ul>
  21. 26.
  22. 28. Over fishing <ul><li>Aquaculture is a vital aspect of the food-production industry </li></ul><ul><li>Global human population is expected to rise to over 9 billion by 2050 </li></ul><ul><li>Placing tremendous pressure on food-production systems </li></ul>Culture 0 Global Fish Supply Year 1980 1950 1960 1970 1990 2000 2025 Million Metric Tons 20 40 60 80 100 120 140 160 Capture (Grainger 1998)
  23. 30. Metric tons of fish caught by year
  24. 31. Invasive species <ul><li>With the increase in ease of travel and shipping, one of the greatest threats by humans is the introduction of invasive species. </li></ul><ul><li>San Francisco Bay (example) </li></ul><ul><li>1850 – 1970 : new species established every 36 weeks </li></ul><ul><li>1970-1996: new species every 24 weeks </li></ul><ul><li>1996-present: new species every 12 weeks. </li></ul>Release of Ballast water
  25. 32. Invasive species Zebra Mussel US and UK Asian Clam San Francisco Coqui frog Hawaii Brow Tree Snake Guam Rabbits Australia Africanized Honeybee South America
  26. 33. Tropical Rainforests Facts <ul><li>Contains more than half of the 5 to 80 million species of plants and animals worldwide. </li></ul><ul><li>Approximately 1/3 of the world’s bird species are found in South American Rainforests. </li></ul>
  27. 34. Tropical Rainforests Facts <ul><li>Each year approximately 78 million acres of rainforest are destroyed. </li></ul><ul><li>As many as 137 species are going extinct each day. </li></ul><ul><li>The substrate (soil) is poor with most of the nutrients existing in the trees and plants. </li></ul>
  28. 35. Tropical Rainforest Facts <ul><li>Poor soil leads to burning the land to increase top-soil nutrients. </li></ul><ul><li>Burning trees releases carbon into the atmosphere which exacerbates the greenhouse effect and increases temperature. </li></ul>
  29. 36. Tropical Rainforest and Population Growth <ul><li>Today, more than 3 billion people live in the tropics alone; more than lived in the entire world in 1950. </li></ul><ul><li>Millions of people are destroying the rainforest simply to survive. </li></ul><ul><li>These people, usually small farmers, have nowhere to grow crops to feed their families, so they wander into the rainforest. </li></ul>
  30. 37. Rainforest and Primates <ul><li>Out of some 240 known primate species, 19 are critically endangered, up from 13 in 1996. </li></ul><ul><li>Their remaining numbers range from less than a few hundred to, at most, a few thousand individuals. </li></ul><ul><li>Includes 8 monkeys from Brazil's Atlantic rainforest, where 97 percent of the forest has been lost, 2 apes and a monkey from Indonesia, 3 monkeys from Viet Nam, 1 each from Kenya and Peru, and 3 lemur species from Madagascar. </li></ul>
  31. 38. Rainforest and Primates <ul><li>In Ghana and parts of the Ivory Coast, the Miss Waldron’s Red Colobus monkey is now extinct. </li></ul><ul><li>“ Chimpanzees lived in what was Africa’s great equatorial forest belt, but it’s not belt anymore just pockets of shrinking forest areas…If things carry on at the present rate in 15 years there will be very, very few chimpanzees left.” Jane Goodall </li></ul>
  32. 39.
  33. 40. Conclusion <ul><li>Humans require a great deal of resources and space and have not had a record of sharing. </li></ul><ul><li>The earth is losing biodiversity at a rate not seen since the mass extinction that killed the dinosaurs 65 million years ago. </li></ul><ul><li>Our increasing numbers will certainly increase the rate at which animals and plants are lost. </li></ul>
  34. 41. Conclusion <ul><li>&quot; For if one link in nature's chain might be lost, another might be lost, until the whole of things will vanish by piecemeal .&quot; - Thomas Jefferson </li></ul>