Human Impact on the Ecosystem (Part 1) Lesson 11

Loss of terrestrial ecosystem When large areas of natural ecosystems are converted into farmland or urban areas, habitat loss can become extreme Fragmentation: breaking once large ecosystems into smaller ecosystems Reduces the sustainability of ecosystems Building with an ecosystem in mind: some factors can help preserve and sustain a fragmented ecosystem and its biodiversity

Loss of Wetlands and Aquatic Ecosystems Damage to ecosystems occurs along lake and ocean shorelines One of the most damaging practices is draining wetlands for building of cities or farmland Commercial fishing have a negative impact on an ecosystem, including species loss and habitat destruction

Pollution Compared to thousands of years ago, people living today have a much greater impact on the environment because: Overall human population has increased dramatically We now use many synthetic and toxic substances We live in a “consumer” society (buy lots of products) Toxic substances released into the environment affect land, water, and air

Some examples of pollutants include: pesticides fertilizers packaging from products automobile exhaust garbage Even biodegradable natural products can cause pollution when they are placed into the environment in high concentrations

Acid Precipitation When fossil fuels (coal, oil, gas) are burned, sulfur dioxide and nitrogen oxides are released into the air, combining with water vapour to form acids. The acids move through the water cycle and eventually return to Earth as acid precipitation or acid rain.

Acid Precipitation on Ecosystems: When acid rain enters aquatic ecosystems, the water becomes acidic and this affects the organisms living in it. Fish, aquatic plants, and other organisms may decline in numbers, disrupting food webs.

When acid rain enters terrestrial ecosystems, the soil becomes acidic and this affects the bacteria and other micro-organisms living in the soil. Plants dying off can significantly affect food webs since all other organisms depend on producers.

Acid Precipitation and Humans Can cause asthma and other respiratory problems Can cause cars and iron structures to rust faster Can damage statues and buildings made of concrete and marble Cause billions of dollars in medical and economic costs each year What can we do? We can persuade our governments to adopt new technologies and laws that regulate pollution emissions We can drive less or use cleaner energy sources (hybrid cars, solar panels)