Transcript 5 - Human Activities in Ecosystems
Human Activities in Ecosystems Human Activities • Cut down forests to make way for new houses, malls and parking lots. • There is usually many of us in a relatively small amount of space, producing too much waste. • Use resources that no other organism does: – Dig the ground for Petroleum – In the process destroy the soil, plants and shrubs in the area, and force birds and other animals to find new habitats. The Consequences of... • Construct Roads and Buildings – Kill plants and organisms living in surface soil. – Change the pattern of the land, altering water drainage – Land can no longer be used as a habitat for animals or to grow crops. The Consequences of... • Dam Building (in order to produce electricity) – Flood land rendering it unusable. – Many land animals and living things are killed during the flooding. – Others are driven away, humans included. The Consequences of... • Cut down a tree to let more sunlight in – Drive away birds and insects that used it as a home and nutrient source. – At the roots, the insects and worms living there can no longer get nutrients. – As the roots die, they no longer help keep the soil together. The Consequences of... • Introduced species – Any species that has been introduced and lives in an ecosystem where it is not found naturally. – These species thrive in new ecosystems because there is few limiting factors to keep their populations in check. – They compete with local native species. Our waste catches up to us... • Watershed – An area of land that drains into a body of water. – Our wastes flow into a system of pipes that eventually lead to a waste-water treament palnts and eventually lakes and rives. • We use this water to: – Drink – Swim in – Allow fish and other animals to live in.