Ecology

What is ecology?

Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings.

Why is it important for scientists to study ecology? Look at the timeline on page 32-33, which entry do you consider the most significant to ecological discoveries?

What do organisms need to survive?

The Biosphere The biosphere contains the combined portions of the planet in which all of life exists, including: –land –water –air, or atmosphere

The Biosphere Biotic Factors –The living factors in an organism’s environment –Exs. Algae, plants, animals Abiotic Factors –The nonliving factors in an organism’s environment –Exs. Air, water, soil, temperature, etc.

How do scientists organize organisms and system in the biosphere?

Organization in the Biosphere To understand the relationships within the biosphere ecologists study: –Individuals –Populations –Communities –Ecosystems –Biomes

Ecosystem Interactions Habitat - Area where an organism lives Vs.

Community Interactions Competition for: –Food –Space –Mate Can be: Among species (same speices) Between species (different species)

Community Interactions Predation

Symbiotic Relationships Relationships that exist when two or more species live together –Mutualism –Commensalism –Parasitism Lichen: mutualistic relationship between fungi and algae

Commensalism A type of symbiotic relationship where one organism benefits by living on or with another, but neither harms nor helps the host. –Cattle stir up insects while grazing and egrets eat them –Mosses, which grow up the trunks of live trees, get better sunlight for photosynthesis, but don't harm the tree. –Barnacles on a whale’s tail (no harm to whale, place to live to barnacles)

Mutualism Two or more organisms live closely together and benefit from each other. The clownfish feeds on small invertebrates which otherwise potentially could harm the sea anemone, and the fecal matter from the clownfish provides nutrients to the sea anemone. The clownfish is additionally protected from predators by the anemone's stinging cells, to which the clownfish is immune. Bees carry pollen (sex cells) from one flower to another to produce seeds

Parasitism Organisms that live and/or feed off another organism (the host), causing harm or death of the host.

Models of Energy Flow Shows how energy moves through ecosystem Simple – food chain Vs. Complex – food web

Cycles of Matter Law of conservation of mass states that matter cannot be created or destroyed Therefore, matter must be recycled through the ecosystem Examples of matter being cycled through an ecosystem include: –Water –Carbon and oxygen –Nitrogen –Phosphorus

Phosphorus Cycle

Environmental Consciousness Why is it important to be conscious of the environment and human interactions with the environment?

Ideas of Conservation and Preservation In 1854, Henry David Thoreau published Walden, a book about living simple in a natural setting. In the summer of 1868, John Muir moved to the Yosemite Valley in California. He would spend weeks hiking through the mountains. In time he became convinced that nature had inherent value of its own and needed to be set aside, put off-limits from the destructiveness of man. Together with Robert Underwood Johnson, he successfully lobbied Congress for the creation of a preserve for Yosemite, and in 1890 Yosemite National Park was born.

Ideas of Conservation and Preservation When President Theodore Roosevelt created the US Forest Service in 1905, he named Gifford Pinchot Chief Forester Pinchot used the knowledge he had gained in France to set up a system of management for natural resources that focused on selective harvest, rather than indiscriminate plunder. Large portions of land (hundreds of millions of acres) were brought under public ownership and made into National Forests, which the Forest Service managed.

Ecological Concerns The next major player in the development of the movement was Aldo Leopold. Leopold began his career with the US Forest Service, where he worked for 19 years. After leaving the Forest Service, he began to work in game management. A Sand County Almanac, published one year after his death in 1948, was a collection of his essays detailing his observations of the natural world around him (The Aldo Leopold Foundation). It explored the complex relationship between organisms and their environment. Aldo Leopold introduced the third branch of the environmental movement, ecology, which focused more on the scientific aspects of the natural world.

The Start of a Movement… Rachel Carson published her revolutionary work, Silent Spring, in Carson was a scientist and writer who began her career with the US Bureau of Fisheries and rose to the position of Editor- in-Chief of all publications for the US Fish and Wildlife Service. Carson became aware of the problems posed by pesticides, and described their danger in Silent Spring. The book received a great deal of attention and caused much controversy, especially within the chemical industry. President John Kennedy set up a commission to study pesticides, resulting in a ban on DDT in 1972.

Events Wilderness Act of 1964 Endangered Species Act of 1973 Clean Air Acts of 1963 and 1970 Water Quality Act of 1965 and Clean Water Acts of 1966 and 1972 Environmental Protection Agency (EPA) established in 1970 First Earth Day, April 1970

The Seeds of the a Revolution Earth Days

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