HUMAN IMPACT on the BIOSPHERE. Part 1. A Changing Landscape

Transcription

1 HUMAN IMPACT on the BIOSPHERE Part 1 A Changing Landscape

2 Humans participate in Food webs & cycles Biogeochemical Ecosystems provide us with GOODS & SERVICES a variety of

3 For image sources: see last slide GOODS & SERVICES provided by ecosystems Solar energy Oxygen production storage & recycling Nutrient

4 For image sources: see last slide Climate GOODS & SERVICES provided by ecosystems regulation Food production Habitats for wildlife

5 Images from: GOODS & SERVICES provided by ecosystems detoxification of human and industrial waste Natural pest and disease control

6 GOODS & SERVICES provided by ecosystems Source of new medicines purification Air & water erosion Soil and management runoff

7 HUMAN ACTIVITIES can change local and global environments! HUNTING AGRICULTURE INDUSTRY URBAN DEVELOPMENT Images from:

8 HUNTING AND GATHERING Throughout human history, people have hunted and fished in rivers, and gathered wild seeds, fruits, and nuts. We are still doing this today in many places.

9 WHEN IT BECOMES A PROBLEM? OVERHUNTING POACHING

10 OVERHUNTING can put animal populations at risk of extinction Miss Waldron s Red Colobus monkey Extinct 2000 Alagoas Curassow: extinct in wild 1980 s Dodo: extinct Moa: extinct 1500 s

11 VOCAB Species that has died out = extinct Species whose population size is rapidly declining and will become extinct if the trend continues = endangered Species that is at risk of becoming endangered in the near future = threatened

12 BIODIVERSITY THREAT Tropical rainforests are disappearing at a rate of about 80 acres per minute.

13 EXAMPLE: WHALES During the 19th and the earlier part of 20th centuries, over-hunting led to a severe of overkill whale populations, and to endangerment of many whale species. Minke whale = most hunted species

14 EXAMPLE: North American Buffalo Wild buffalo in America once numbered million, ranging from Virginia to Alaska and all points in between. Pile of bison skulls, 1870 s By 1884, the buffalo was close to extinction due to. overhunting

15 WHAT PROBLEMS CAN THIS CAUSE? Many endangered animals today are threatened by Illegal poaching

16 WHAT CAN WE DO TO HELP? Support Green organizations that work for laws to establish quotas and protect species

17 HUMAN ACTIVITIES can also change local and global environments! HUNTING and GATHERING AGRICULTURE INDUSTRY URBAN DEVELOPMENT Images from:

18 By end of last ice age (about 11,000 years ago) humans began the practice of farming = AGRICULTURE Soon people around the world were growing crops and raising animals for food agriculture

19 Changing Agriculture The spread of agriculture was one of most important developments in human history. It provided food in large quantities that could be stored for later. Allowed people to settle in one place and enabled the of development cities, governments, laws, and writing.

20 GREEN REVOLUTION 1. New more productive plant strains 2. Modern farming techniques allowed planting larger areas 3. Chemical Fertilizers & pesticides boosted crop production and controlled pests

21 Changing Agriculture Over the last 50 years, the green revolution has helped world food production. double Even though hunger is still a major problem in parts of the world, agriculture and the green revolution have provided many people with better nutrition.

22 Challenges for Future Modern agriculture has increased world, food supplies but has also created ecological challenges. Large scale monoculture leads to problems with Insect pests and. diseases Use of farm chemicals (fertilizers & pesticides) can damage beneficial insects, contaminate water supplies, and accumulate in the environment

23 Challenges for Future Finding enough water for irrigation is another problem. Less than ¼ of US farmland relies heavily on, irrigation but this area produces a major portion of our harvest.

24 HOW DO WE HELP? Applying modern technology to farming is changing some of this environmental impact. EX: Satellite imaging and GPS technology enable farmers to apply chemicals only where needed

25 HOW DO WE FIX IT? EX: No-till and other green farming methods can reduce soil erosion and protect ecosystems

26 Sustainable Agriculture Ways Section 6-4 to preserve the environment Cover Crops Legumes, grasses, and other cover crops recycle soil nutrients, reduce fertilizer need, and prevent weed growth. Controlled Grazing By managing graze periods and herd densities, farmers can improve nutrient cycling, increase the effectiveness of precipitation, and increase the carrying capacity of pastures. A B C Biological Pest Control The use of predators and parasites to control destructive insects minimizes pesticide use as well as crop damage Contour Plowing Contour plowing reduces soil erosion from land runoff. On hilly areas, plowing is done across the hill rather than straight up and down. Yr. 1 Yr. 2 corn corn oats alfalfa alfalfa (plowed in) Crop Rotation Different crops use and replenish different nutrients. By rotating crops, the loss of important plant nutrients is decreased. Yr. 3 oats alfalfa corn

27 INDUSTRIAL GROWTH and URBAN DEVELOPMENT The impact of humans on the biosphere was transformed by the INDUSTRIAL REVOLUTION during the 1800 s.

28 Industrial productivity and scientific advancements have provided us with the we enjoy today modern conveniences

29 BUT... The spread of urban areas has resulted in the destruction habitats. Air, water, & soil pollution has had an impact on surrounding ecosystems.

30 Energy production requires burning fossil fuels which impacts air quality and. global climate