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Mans Impact On The Environment Effect of invasive species on an environment Consequences of human activity on the environment

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In Todays Lesson We Will Be Learning About: The effects of deliberate or accidental introduction of species to new habitats The effects of the removal of endemic species which have led to the alteration of the environment The consequences of human activity on the environment

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Before we begin, lets review What is an endemic species? An endemic species is one which can be found only in one place because of isolation or geographical location, do not confuse with indigenous which means native to a region or place. For example: all lemurs are endemic to Madagascar, they can only be found in Madagascar.

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Dynamic equilibrium a state of balance in an ecosystem; it is fragile as it can be easily upset by any change in the environment such as human exploitation and introduced species Extinction no longer existing

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What is an invasive species? It is a non-native or alien species to the eco-system. It is not indigenous to the area

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What would happen if an invasive species is released into an ecosystem? Its introduction is most likely to cause economic or environmental harm.

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How have humans altered the environment or ecosystem by adding invasive species into it or removing endemic species?

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These activities have caused harm to the environment by: Upsetting the dynamic equilibrium of the ecosystem Invasive species can threaten native or indigenous species as well as endemic species. It can even cause species to become extinct

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Lets look at an example of this, Im sure you have heard of the dodo bird lets learn how it became extinct!

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The dodo bird was a native to the island of Mauritius in the Indian Ocean. It had no natural predators so over the years it lost its ability to fly.

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The Portuguese were the first humans to set foot on the island in 1505. sailors who stopped over on the island killed a large number of dodo birds for food.

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Rats from ships, and pigs and monkeys brought by the Dutch to the island ate up the dodo eggs.

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The dodo became extinct in 1681

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A certain species of tree now called the dodo tree, became rare after the extinction of the dodo bird. This is because the dodo bird ate the fruits of the tree and the seeds could only germinate after passing through the dodo birds digestive system. Do you think the tree would now be extinct?

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What are the consequences of human activity on the environment? Deforestation Depletion of Natural Resources Increased Levels of Pollution

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Consequences of Human Activity Humans have impacted the environment in many negative ways The activities that we do, which may be bettering our lives have serious environmental consequences

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Deforestation This is the clearing of forests on a large scale usually done by cutting or burning. The area is then converted into non- forests, that is trees are no longer grown there.

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Deforestation Facts Up to 90 percent of West Africas coastal rain forests have disappeared since 1900. Brazil and Indonesia, which contain the worlds two largest surviving regions of rain forest are being cleared rapidly

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Why do we deforest areas? Charcoal is obtained from trees which is used for fuel Trees are also used for timber building houses and furniture Forests are cleared for pasture land to graze livestock, for plantations(agriculture), and for the building of settlements or industries

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The effects of deforestation Atmospheric effects Hydrological effects Soil damages Loss of Biodiversity

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Atmospheric Effects Deforestation contributes to global warming It is one of the major causes of the enhanced greenhouse effect - as trees remove carbon dioxide from the air

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Hydrological Effects Tress extract ground water from their roots and release it into the atmosphere via evaporation which is a main part of the hydrological cycle. Leaves control the humidity of the atmosphere

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Effects on the soil Tress hold soil particles together, when removed there is a lot of erosion and landslides The soil becomes exhausted as there is no added humus There are no trees to intercept the rainfall which further erodes top soil

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Effects on biodiversity Forests are home to many plant and animal species, deforestation destroys their habitat. Species which are endemic may become extinct

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The Congo Basins 500 million acres of tropical forest, second-largest in the world after the Amazon, are known for an incredible array of wildlife including great apes, forest elephants, and some 700 species of river fish. But people have also lived here for over 50,000 years. The Congo Basin currently provides water and food to about 75 million Africans.

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Cattle graze among the scarred remains of what used to be a lush stretch of the Amazon rain forest in the Brazilian state of Rondonia. Cattle ranching is the leading cause of deforestation in the Brazilian Amazon, eating away at thousands of square miles of irreplaceable forest lands every year.

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A clearing in Gunung Palung National Park in Indonesian Borneo reveals an illegal logging operation, where loggers fell and mill trees into lumber on site. Deforestation in this area threatens the endangered orangutan population.

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Scars of bald earth, exposed by slash-and-burn deforestation, encroach on the forests of northeastern Madagascar. Economic pressures have driven the government to exploit one of the most biologically rich areas on Earth for cultivation of coffee beans.

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Depletion of Natural Resources Resource depletion occurs when certain natural resources are becoming more scarce The natural resources which are being most depleted are fossil fuels - oil, gas and coal. Forests which are an important natural resource are also being depleted rapidly (deforestation)

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Causes of Resource Depletion Overpopulation Mining and drilling excessively Slash and burn agricultural practices Pollution Industrial development Over fishing

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Effects of this Depletion Problems for future generations Loss of species Extinction Loss of biodiversity

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The Aral Sea the sea was once filled with water but humans channeled the water from the sea for irrigation of crops and exhausted the water.

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This is a part of the dried Aral Sea

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Overfishing

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Drilling For Oil

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Pollution Pollution is defined as the introduction of contaminants into a natural environment. There are many types of pollution: land, water, air and soil

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Pollution Facts 40% of Americas rivers and 46% of Americas lakes are too polluted for fishing, swimming, or aquatic life. Polluted drinking waters are a problem for about half of the worlds population. Each year there are about 250 million cases of water-based diseases, resulting in roughly 5 to 10 million deaths.

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Pollution Facts Each year, U.S. factories spew 3 million tons of toxic chemicals into the air, land, and water Every year, one American produces over 3,285 pounds of hazardous waste Over 80% of items in landfills can be recycled, but theyre not

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What causes pollution? Improper disposal of any type of waste Over production Over population in an area Improper use of technology (atomic bombs)

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Effects of pollution Disrupts ecosystems Damages the environment Causes mutations (nuclear or radioactive pollution) Causes human health implications Global warming Species extinction Loss of biodiversity

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Water Pollution

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Air Pollution

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Oil Spill - Water Pollution

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Soil/ Land Pollution

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Effect of Noise Pollution on Whales

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Sea Ducks Coated With Oil

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Death of Marine Life