Humans in the Biosphere Chapter 6 Humans in the Biosphere

6-1 The Effect Of Human Activity In the beginning of the 1700’s a wave settlers traveled to Hawaii. They imported plants and animals that eventually became invasive. Clearing tons of land for a growing population and tourism they built buildings and homes. They planted sugar cane and pineapples, both which require a lot of water. What happens when humans do not adequately manage natural resources that are both vital and limited?

Living on Island Earth Humans rely on earths life support systems. Human activity has used or altered half of all land that is not covered with ice or snow. Some believe that as the population reaches toward 7 billion on earth we are reaching the carrying capacity Humans rely on earths life support systems. We effect our environment when we obtain food, eliminate waste and build places to live. Humans affect regional and global environments through agriculture, development and industry.

Agriculture Agriculture is one of the most important inventions in human history. Agriculture allows for humans to store food and grow cities and towns. Modern agriculture has enabled farmers to double food production. Monoculture is the practice of clearing large amounts of land for a single highly productive crop. Monoculture enables efficient sowing, tending and harvesting of crops every year.

Development As modern society developed many people decided to live in large cities. In the US, as urban cities become crowded, people chose to live in suburbs. In addition, development consumes farmland. Dense human communities produce a lot of waste. If wastes are not disposed of properly they affect air, water and soil.

Industrial Growth Human society was transformed with the Industrial revolution in the 1800’s. Industry and scientific know how provide us with modern life. Conveniences of modern life require a lot of energy. We obtain this energy by burning fossil fuels. Fossil fuels include coal, oil and natural gas.

Ecosystem Goods And Services Ecosystem good and services include air and water. Healthy ecosystems provide goods and services relatively free of charge. If the environment cannot provide these services, society must pay to produce them. In many places rivers streams and lakes provide free water. If they were to be contaminated society would have to pay to treat it.

Renewable and Non Renewable Resources A renewable resource can be replaced by a healthy ecosystem. Trees are an example of renewable resources because another can grow after one dies. A non renewable resource cannot be replaced in a reasonable amount of time. Fossil fuels are non renewable resources. When existing deposits are depleted, they will be gone forever.

Sustainable Resource Use Ecological science can teach us how to meet our needs without causing problems to our environment. Using resources in a environmentally conscious way is called sustainable development. Sustainable development provides for human needs while preserving ecosystems that produce natural resources. Sustainable development should cause no long term damage. Sustainable development must also be able to withstand environmental stresses.

6-2 Soil Resources Many objects you rely on daily come in contact with soil – grain your cereal, wood in your desk, to the paper in a book. Healthy soil supports agriculture and forestry. The mineral rich and nutrient part of soil is called top soil. Top soil, if managed correctly is a renewable resource. Healthy soil can take years to form but can be lost very quickly.

Soil Erosion Soil erosion is the removal of soil by water or wind. Soil erosion is often worse when land is plowed and left barren between plantings. A combination of farming, overgrazing seasonal draught and climate change causes desertification. 40 percent of earths land is at risk of desertification. Deforestation is the loss of forest. Half of the worlds growth forest have been lost to deforestation.

Soil Use And Sustainability Its possible to minimize soil erosion through careful management of both agriculture and forestry. Soil is most vulnerable when it is completely bare. Leaving in stems and roots from last years crop can protect soil. Altering shapes of land can limit soil erosion. This limits water run off, thus stopping soil erosion.

Freshwater Resources Humans depend on freshwater ecosystems for goods and services. Some of these goods and services are drinking water, industry, transportation, and waste disposal. Some of the most productive farms rely on irrigation from other outside sources. Freshwater is renewable Some aquifers are not renewable, like the Ogallala aquifer which spans from Texas to South Dakota.

Water Pollution A pollutant is a harmful material that can enter the biosphere. Point source pollution is when pollutants enter the water from a certain source, for example, a factory or oil spill. Non point source pollution usually comes from cars, factories and run off. The exact location is hard to find. The primary sources of water pollution are industrial and agricultural chemicals, residential sewage, and nonpoint sources. Biological Magnification occurs if a pollutant is picked up by an organism and is not broken down or eliminated from its body.

Water Quality And Sustainability It is key to protect the natural systems involved in the water cycle. Protecting ecosystems is a critical part of watershed conservation. A watershed includes all the land whose groundwater, streams, rivers, drain into the same place Pollution control can have direct and positive effects on the water quality in a watershed. Water conservation is also important.

Atmospheric Resources The atmosphere is a common resource whose quality has direct effects on all humans. The atmosphere provides the air we breathe. The atmosphere absorbs ultraviolet radiation. The atmosphere regulates temperature. The atmosphere can never be used up.

Air Pollution If air quality drops, humans can suffer many illnesses. Common forms of air pollution include smog, acid rain, greenhouse gases and particulates. Smog is gray brown haze formed by chemical reactions among pollutants released into the air. Acid rain is rain containing nitric and sulfiric acids Greenhouse gases are caused by the burning of forest and fossil fuels. Particulates are microscopic particles of ash and dust released into the air.

Air Quality And Sustainability Air quality improvement is difficult. Air cannot stay in one place. Automobile emission standards and clean air regulations have improved air quality in some regions. In 1996 the sale of lead gasoline was banned. Now that unleaded gasoline is used across the United States lead levels in rivers, streams, and soil have dropped dramatically.

6-3 Biodiversity Biodiversity is the total variety of all organisms in the biosphere. To biologist, biodiversity is precious and worth saving.

Types of Biodiversity Biodiversity exists on three levels. Ecosystem diversity, species diversity and genetic diversity. Ecosystem diversity is based on habitats and ecological processes Species diversity is based on the number of species in an area. Genetic diversity refers to the sum total of all different forms of genetic information carried by a particular species.

Valuing Biodiversity Chemicals in wild species treat certain diseases, like depression and cancer. Each crop has a wild relative. The number of species in an ecosystem can influence that ecosystems stability, productivity and value to humans.

Threats To Biodiversity Scientist believe that all species that have ever lived are 99 percent extinct. Human activity is causing the biggest wave of extinction through all animals.

Altered Habitats When habitats are cleaned out for urban development or farming the amount of species in that habitat dissipates exponentially. A habitat does not need to be completely destroyed to be put at risk. The smaller the habitat, the smaller amountof species are that can live on it.

Hunting And The Demand For Wildlife Products Humans can push species to extinction by hunting. Today endangered species in the United States are protected from hunting World wide, CITES protects all animals.

Introduced Species Organisms introduced into a new habitat can become invasive and threaten biodiversity In the great lakes over 130 species were added to the Great Lakes, they have driven out native species Each year, farmers surfer from Introduced species because they drive away their profit

Pollution Pollutants threaten biodiversity DDT for example, inhibits birds from laying healthy eggs Acid rain pushes stress on land and water organisms.

Climate Change Climate change drives out certain species from their habitat. If global temperatures rise between 1.5 and 2.5 degrees Celsius, 30 percent of species will go extinct. If temperatures rise past 3.5 degrees Celsius, 40 to 70 percent of all animals on earth will go extinct.

Conserving Biodiversity To conserve biodiversity certain species have to be protected. Habitats need to be clean and taken care to conserve biodiversity.

Protecting Individual Species In the past most conservation focused on Individual species. The association of zoos and seaquariums now oversee special species survival plans. A large part in ther plans are captive breeding programs, to bring many birds and animals back to life.

Preserving Habitats And Ecosystems Todays main goal is not just to protect one set of species, but rather whole ecosystems at a time. This goal will alow to keep interactions between all animals the same. Parks and forests allow animal habitats to be protected.

Considering Local Interests Protecting biodiversity means changing your life and others locally. In some cases, government offers many incentives to conserve our biodiversity. The United States offers a tax credit to those who have bought a hybrid car or installed solar panels to their homes. In example, farmers in Australia were payed to plant a certain plant.

6-4 Ecological Footprints Ecologist refer to our impact on earth using a concept called the ecological footprint. An ecological footprint describes the total area of functioning land and water systems needed both to provide the resources an individual or population uses and make harmless the wastes that the individual or population generates.

Footprint Limitations As of today theres no way to calculate a footprint size. Footprints only give a “snapshot” of the situation at a particular time.

Comparing Footprints Footprints allow scientist to compare different populations on our planet. An American has a global footprint 4 times larger than the global average. To determine the size of the ecological footprint of a country, they get the average of a person and multiply it by the amount of people in that country.