Humans and the Biosphere

notes on Forests:

called "lungs of the Earth" because they remove carbon dioxide & produce oxygen. Role/job of forests: store nutrients, provide habitats & food for organisms, moderate climate, limit soil erosion, & protect freshwater supplies. "Old-growth forests" = forests that have never been cut (located in Alaska & Pacific Northeast. *whether a forest is considered a renewable resource or not depends partly on the type of forest. Temperate forests of Northeast US are renewable. Old-growth forests are not.

Smog

A grey-brown haze formed by a chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

pollutant

A harmful chemical or waste material discharged into the water, soil, or air.

Ecological hot spot

A place where significant numbers of species and habitats are in immediate danger of extinction.

Acid Rain

A process of burned fossil fuels that release nitrogen and sulfur compounds that combine with water vapor in the air to form nitric and sulfuric acids.

green revolution

A shift in agricultural practices in the twentieth century that included new management techniques, mechanization, fertilization, irrigation, and improved crop varieties, and resulted in increased food output.

endangered species

A species whose population size is declining in a way that places it in danger of extinction

chloroflourocarbons

called CFCs - damage the ozone layer. Once used in aerosol cans, coolant in refrigerators, freezers, & air conditioners, and is production of plastic foams. Today use of CFC is mostly banned. CFC molecules can linger for over a century so still their effects are not yet over. It is believed that the ozone holes should shrink & disappear as chlorine is atmosphere is dropping.

notes on soil:

fertile soil: a mixture of sand, clay, rock particles, and humus (materials from decayed organisms). topsoil: uppermost layer of soil - rich in nutrients but low in salts. produced by long-term interactions between the soil & plants growing in it.

NOTES: human activities and impact

global human activities use as much energy and transport almost as much materials as all Earth's other multicellular species combined. Hunting, gathering, agriculture, industry and urban development affect biosphere.

particulates

microscopic particles of ash and dust that can enter the nose, mouth and lungs causing health problems.

Notes: Modern Agriculture

Farmers eventually acquired machinery (plows, & seed drill). In the 1800s and 1900s, advances in science & technology brought significant changes. Machinery for plowing & harvesting helped farmers increase their yields. Agricultural scientists developed new varieities of crops that produced higher yields. Chemical fertilizers boosted plant growth & pesticides controlled crop-damaging insects.

What supports both agriculture and forestry?

Healthy soil

Why is soil important and how do we protect it?

Healthy soil produce things like grain for your cereal that humans eat. We protect it by managing the agriculture (adding fertilizers, not over grazing\farming) and forestry (planting trees, contour plowing).

Notes on Ozone layer & ozone depletion:

*Ozone at ground level is a pollutant, ozone at the naturally occurring layer is needed & has important functions. 1970's a gap or "hole" in ozone layer over Antarctica. The layer is also thinning. Another found over the Arctic. **gases called CHLOROFLOUROCARBONS, or CFCs, damage the ozone layers.

NOTES: Ecological life-support systems & ecosystem goods and services

*all humans participate in food webs and chemical cycles - we depend on these ecological life-support systems to provide breathable air, drinkable water and fertile soil that support farming. *also, ecosystem processes provide "services" such as storage and recycling of nutrients - These are referred to as "ecosystem goods and services" - if the environment didn't provide, man would spend great deal of $ producing them.

NOTES - Earth as an island

all organisms that live on Earth share a limited resource base and depend on it for their long term survival - we all rely on natural ecological processes that sustain these resources.

Notes: Challenges for future (modern agriculture has created ecological challenges).

1. Large-scale monoculture can lead to problems with insects and diseases. When insect pop grows, chemical use up which can damage beneficial insects, contaminate water supplies, & accumulate in the environment. 2. How to find enough water for irrigation 2nd challenge. Less than a quarter of American farmland relies on irrigation but that land produces a major portion of our harvest. Several states depend on the OGALLALA AQUIFER, an underground water deposit, which is not expected to last more than forty or so years. So...how do we maintain the benefits of modern agriculture while protecting natural resources.

How does the average ecological footprint in America compare to the world's average?

4x larger

Notes: agriculture/farming and its overall impact

Agriculture enabled man to build a food supply and store later. Because food supply available, less traveling and hunting was required. Man began to gather in large settlements, stable communities enabled the development of civilization (government, laws & writing).

notes on global climate change:

All life on earth depends on climate conditions such as temperature and rain fall. Ecologists are concerned about the slow and steady increase of atmospheric temperature. This increase in temp is referred to as "global warming". *Data shows that the concentrations of carbon dioxide in the atmosphere have been rising for last 200 plus years. The result is that the Earth's natural greenhouse effect is intensified, causing the atmosphere to retain more heat. Effects of global warming: sea levels rise enough to flood coastal areas. flooding affects coastal ecosystems & human communities. There will be more droughts & organisms may be threatened or extinct in areas they once thrived.

extinction

An even where all organisms from a population disappear indefinitely from a patch of habitat previously occupied

agriculture

Another word for farming. * the development of agriculture can include raising animals (sheep, goats, pigs, etc). *agriculture is one of the most important developments in human history because it supplies humans with a dependable food supply that can be stored for later use.

renewable resource

Any natural resource that can replenish itself naturally over time. Example: fresh water

Ozone layer

Between 20 and 50 kilometers above Earth's surface, absorbs harmful ultraviolet (UV) radiation from sunlight, at ground level it is a pollutant.

Name three ecosystem goods and services you might have used today

Breathable air, drinkable water, gas in your car.

Notes: Green Revolution

By middle of 20th century food shortages prompted governments & scientists to make efforts to increase food production. Plant breeders developed "miracle strains" of wheat & rice. Monoculture & chemical fertilizers were used. These efforts became known as the GREEN REVOLUTION because it greatly increased world's food supply. *has helped world food supply double & has provided better nutrition.

Renewable Resource

Can be produced or replaced by a healthy ecosystem. An example might be a single southern white pine because a new tree can grow in place of an old tree that dies or is cut down.

conservation

Careful use of resources, including the preservation of habitats and wildlife *today conservation efforts focus on protecting entire ecosystems as well as single species. Protecting an ecosystem will ensure the natural habitat and the interactions of many different species are preserved at the same time

Ways to preserve ecosystems and keep the biosphere healthy:

Make wise choices and use resources conservatively. Replace trees when cut down others. Recycle trash and other wastes. Properly remove hazardous waste. Replenish fisheries and preserve ozone layer.

habitat fragmentation

Destruction of a part of an area that separates suitable habitat patches from one another; patches that are too small may be unusable for some species. Splitting of ecosystems into small fragments - often fragments referred to as "biological/abitat islands" as they are a patch of a habitat surrounded by a different kind of habitat. EX: New York's Central Park as it is surrounded by concrete. ** the smaller the 'island" the fewer species live there, the smaller their populations can be & the more vulnerable they are to further disturbance or climate changes.

deforestation

Destruction of forests - can lead to severe soil erosion when soil exposed to heavy rains. Erosion can wash away nutrients in the topsoil. Grazing & plowing after deforestation can cause permanent changes to local soils & microclimates that prevent regrowth of trees. Ways to mange/protect forests: a) mature trees can be harvested selectively to promote growth of younger trees & preserve forest ecosystem b) tree geneticists are breeding new, faster-growing trees varieties that produce high-quality wood c)in areas where forests have been cut down, foresters today plant, manage, harvest & replant tree farms.

Name the three types of Biodiversity?

Ecosystem diversity, Species diversity and Genetic diversity

notes on Fishery resources:

Fishes and other animals that live in water are a valuable source of food for humanity. Overfishing = harvesting fish faster than they can be replaced by reproduction. - an example of the "tragedy of the commons". Until recently, fisheries seemed to be a renewable resource that could be harvested indefinitely. *ways to manage fisheries - a)new guidelines determine what size fish and how many can be caught (this is helping fish pop recover) b) aquaculture

Threats to Biodiversity:

Human activity can reduce biodiversity by altering habitats, hunting species to extinction, introducing toxic compounds into food webs, & foreign species to new environments.

What is the relationship between resource use and sustainable development?

Humans must balance resource usage in order to sustain the ecosystems that produce natural resources.

"tragedy of the commons"

Hundreds of yrs ago villagers would graze their cattle on shared pasture land called commons. Overgrazing often led to deterioration of pastures. This phrase is used today when referring to any resource that is free and accessible to all that may eventually be destroyed/overused.

Ways in which pollution threaten water supplies:

Improperly discarded chemicals can enter streams & rivers. Wastes discarded onto land can seep through soil & enter underground water supplies we tap with wells. Domestic Sewage ( wastewater from sinks & toilets) contains nitrogen & phosphorous compounds that can encourage the growth of algae & bacteria in aquatic habitats. Sewage can also contain microorganisms that spread disease among humans & animals. Ways to ensure sustainable use of water: a) protect natural systems involved in water cycle. EX: protect wetlands that purify water as it passes through them b) conservation of water Ex: drip irrigation delivering water directly to roots of plants

desertification

In areas with dry climates, a process caused by a combination of poor farming practices, overgrazing, and drought that turns productive land into desert. **ways to prevent desertification: a.) contour plowing - fields are plowed across the slope of the land to reduce erosion. b.) leaving the stems & roots of the previous years crops in place to help hold soil together c.) planting field with rye rather than leaving it unprotected from erosion.

CITES = Convention on International Trade in Endangered Species

bans international trade of products derived from a list of endangered species. It is difficult to enforce these laws in remote wilderness areas however.

What are the primary sources of water pollution?

Industrial and agricultural chemicals, residential sewage and nonpoint sources.

Notes on Land Resources:

Land is resource that provides space for human communities & raw materials for industry. Includes the soil in which crops are grown. Soil is a renewable resource if managed well. It can be permanently damaged if it's mismanaged.

Biological magnification

Occurs if a pollutant (such as DDT, mercury or a PCB) is picked up by an organism and is not broken down or eliminated from it's body. The pollutant concentration increases to high trophic levels and causes problems for wildlife and humans.

invasive species

Plants and animals that have migrated to places where they are not native. Invasive species increase their populations because new habitat lacks parasites & predators to control them

What are the major forms of air pollution?

Smog, acid rain, green house gases and particulates.

notes on Freshwater:

Water is a renewable resource but the total supply is limited. For this reason, protecting it from pollution and managing society's growing demand for are major priorities.

Notes on Industrial Growth and Urban Development:

The Industrial Revolution added machines and factories to civilization during 1800s. To produce & power these machines we need energy. To obtain energy, most comes from fossil fuels ( coal oil & natural gas). *for many years cities & industries discarded waste from manufacturing, energy production & other resources into the air, water & soil. Suburban growth consumes farmland & natural habitats & places additional stress on plant & animal populations

Why is biodiversity important?

The benefits to society include contributions to medicine and agriculture, and the provision of ecosystem goods and services.

Global warming

The increase in the average temperature.

biodiversity

The diversity of plant and animal life in a particular habitat (or in the world as a whole).**Biodiversity is one of Earths greatest natural resources. Species of many kinds have provided us with foods, industrial products & medicines - including painkillers, antibiotics, heart rugs, antidepressants &anticancer drugs.

Aquaculture

The farming of aquatic animals.

Species diversity

The number of different species in the biosphere or in a particular area.

Monoculture

The practice of clearing large areas of land to plant a single highly productive crop year after year.

Genetic diversity

The sum total of all different forms of genetic information carried by a particular species, or by all organisms on earth.

sustainable development

Using natural resources to meet the needs of today's population without sacrificing or hurting those of the future. *To work well, sustainable development must take into account both the functioning of ecosystems & the way that human economic systems operate. EX. of: use of insects to control insects.

Ecological footprint

The total area of functioning land and water ecosystems needed both to provide the resources and individual or population uses and to absorb and make harmless the wastes that individuals or population generates.

Ecosystem diversity

The variety of habitats, communities and ecological processes in the biosphere.

soil erosion

The wearing away of surface soil by water and wind - the rate of soil erosion can be increased by the act of plowing - plowing land removes the roots that hold the soil in place.

How do our daily activities affect the environment?

This is done by agriculture, development and industry in ways that have an impact on the quality of Earth's natural resources, including soil, water and the atmosphere.

What does the prefix 'mono' mean?

This means 'one', 'alone', 'single'

How can ecology guide us towards a sustainable future?

We can have a positive impact on the global environment: 1- By recognizing a problem in the environment, 2-researching that problem to determine its cause, 3-using scientific understanding to change our behavior.

How do we preserve biodiversity?

We have to protect individual species, preserve habitats and ecosystems. We also have to educate humans and reward them if needed to change the habits. Example: Paying farmers to plant trees that improved water quality and provided shade for cows.

biodiversity "hot spot"

a place where significant numbers of habitats are in danger of extinction as a result of human activity. Conservationists identify them and hope that governments & scientists focus efforts where needed.