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28 Cards in this Set
- Front
- Back
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What is an ecosystem?
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The organisms of a habitat and its chemical and physical properties.
Biotic and abiotic factors. |
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What is a population?
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Group of organisms of same species living together.
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What is a community?
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Group of interacting species living together.
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What are abiotic factors?
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Physical properties of a habitat.
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What are the levels of organization?
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Atom, molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem.
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What is global change?
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Planetary-scale changes in biophysical and/or socioeconomic processes altering structure and function of Earth.
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What is Anthropocene?
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Current period in Earth's history characterized by the large changes humans have had on ecosystems at a global scale.
Term coined by Nobel Laureate in 2000. |
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What is the Millennium Ecosystem Assessment?
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2005.
First assessment if global ecosystem health. Outlined recent, current, and future trends in global ecosystem health. Expert review process. GOAL: strengthening capacity to manage ecosystem sustainability for human well-being. |
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What are examples of some substantial and sometimes irreversible ecosystem losses over the past 50 years?
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More land was converted to cropland in the last 50 years then in 150 years.
20% of coral reefs were lost in the last few decades. 35% of mangrove area was been lost in the last several decades. |
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What are the five main forms of global change?
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1. habitat change
2. climate change 3. invasive species 4. over-exploitation 5. pollution |
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Past, present, and future summary results from MEA?
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Past: problems with over-exploitation and invasive species.
Present: habitat change. Future: climate change. |
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Why are tropical evergreen forests important? How are they endangered?
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They are the earth's most species-rich biomes.
Rapidly increasing our impact on them...being lost at a rate of 2% so 1 mill species could go extinct by the end of the century. (Habitat change). |
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What is the general rule for land conservation?
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With 90% loss of habitat area=loss in half of species that live and depend on that habitat.
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What is the importance of habitat patch size?
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Patches are influenced by edge effects...bigger patches=smaller edges.
Its better to have a few large reserves than a lot of small ones. |
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What are the importance of corridors?
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They help maintain species diversity.
Isolated patches lose species much more quickly. Better to be connected to the forest. |
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Are tropical evergreen important in terms of moderating climate change?
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Per meter squared, they are very productive in terms of fixing carbon. But because the ocean is so big, it contributes more to Earth's net primary production.
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Describe the greenhouse effect.
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UV comes from the sun, some is filtered out by the ozone, some is absorbed by Earth. On earth it is converted into lower wavelengths and radiated away. But greenhouse gases reflect these so they come back to Earth. Causes warming.
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What are the greenhouse gases?
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CO2, CH4 (methane), N2O (nitrous oxide).
Methane has a greater effect, but there is more CO2 and it resides longer. |
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How is climate change effecting earth?
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Polar regions effected the most.
Having an increasing impact on all regions. |
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Why are polar regions particularly susceptible to climate change?
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Changes in albedo.
As the temps warm up, it melts the snow and ice which makes a darker landscape. Darker landscapes absorb more light. |
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What are the predicted changes regarding climate?
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~+3 C in 100 years.
The main unknown is not the science, its how economics and politics will change emissions. |
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Why is the present climate change a big deal?
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1. ethical dimension: caused by humans.
2. Its happening at a very fast rate compared to history. |
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What are the consequences of climate change?
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Species will change their distribution.
Loss of coral reefs. Melting glaciers-rising seas. Increased tropical diseases. Increased droughts. More tropical storms. |
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Where are invasive species most problematic? Why?
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Islands. Because they are isolated so uniquely sensitive to predators.
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Where is over-exploitation most severe?
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Tropical grassland and savannah, and marine biomes.
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How has over-exploitation effected commercial fishing?
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They deplete a fish population, and then more to a new area.
Started a trend towards depleting top predators and fishing at greater depths. |
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What is a possible solution to the over-exploitation of commercial fishing?
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Marine reserves.
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What does pollution effect?
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Nutrient pollution has had a more devastating impact on aquatic ecosystems and temperate grasslands.
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