PER Module 3
Discuss how terra preta exemplifies both "natural" and human-induced environmental change.
Tera preta, or "black earth", is a type of nutrient rich soil caused by specific burning and farming practices of native Amazonians thousands of years ago in the Amazon Rainforest. The human-induced changes that cause tera preta are the burning methods used: simply charring the organic matter instead of complete combustion. The tera preta is also natural because it regenerates itself: the soil hosts microorganisms that continue to create dark soils.
What is a keystone species?
A keystone species is a species that is so important to the ecosystem that it can limit the distribution and community structure of many species in an ecosystem through direct or indirect effects.
What causes air and ocean water to flow?
Air flows due to changes in pressure, wind flows from areas of high pressure to areas of low pressure. Flowing ocean waters are caused by the uneven heating of the Earth's surface.
What is albedo?
Albedo is a measure of the reflecting power of a surface.
Why do coasts have milder climates compared to continental interiors?
Coastal areas are cooler in summer and warmer in winter than the middle of continents because of breezes caused by the differential heating properties of land and water.
Define community and biome.
Community refers to a group of interdependent organisms of different species growing or living together in a specified habitat while biome refers to a large naturally occurring community of flora and fauna occupying a major habitat.
Describe the three main ways organisms interact and provide examples for each type of interaction.
Competition - individuals compete over a resource Predation - when one species benefits and one suffers Mutualism - when each species benefits the other
What is low and high (air) pressure and what causes differences in pressure?
Differences in air pressure are caused by differential heating of the Earth's surface and cause winds to flow from high to low pressure areas.
What factors are most influential of ecosystem patterns at the global and regional scales?
Ecosystems at the global and regional scales are most influenced by global climate patterns, elevation differences, and distance to bodies of water (continentality).
Why is it more realistic to speak of multiple stable states instead of single climax communities?
It is more realistic to speak of multiple stable states instead of a single climax community because climax communities can change.
Name the four factors determining global patterns of climate (temperature, precipitation, and air movement or wind)
Latitude, land/water differences, elevation, and urban heat islands.
Define limiting factor, range of tolerance, generalist, and specialist; discuss an example for each term.
Limiting factor - a factor that is essential to a population and restricts them (for example: a species that is dependent on a certain plant that is only available in certain areas) Range of tolerance - an organisms limits of a certain environmental factor (for example: fish and temperature of water) Generalist - a species that can survive over many different habitats (for example: mice) Specialist - a species that needs a certain habitat in order to survive
What are the two most influential factors affecting individual organisms and species distributions?
Limiting factors and species interactions (competition/predation/mutualism)
Explain how precipitation happens.
Precipitation happens when clouds form and become too heavy, the release of water from the clouds is precipitation.
What are the five factors that mainly affect global vegetation distributions?
Precipitation, temperature, soil type, disturbance, and elevation all effect global vegetation distributions.
Why does it get colder with higher elevation?
Pressure is reduced with increasing elevation, which explains why it gets colder at higher elevations.
Describe and give examples of scale dependency in ecosystem analysis.
Scale dependency refers to the fact that certain variables or factors appear to have a greater effect on ecosystems depending upon the scale it is shown at. For example: vegetation formations could be seen as at risk at a certain scale but at a different scale they could seem unharmed.
What is the urban heat island effect and what causes it?
Since urban areas consist of mainly cement, have a lot of exhaust, and don't have a lot of plants, they often have a higher temperature (retain heat more than other areas).
Why does solar radiation intensity vary according to location?
Solar radiation varies in intensity according to location due to the tilt of the Earth's axis and the angle of incidence.
Why does land heat up or lose heat more rapidly than water?
The heat on land is concentrated near the surface while the heat in water is distributed over a great volume. Land is also opaque while water is transparent.
Describe orographic and rain shadow effects and how they affect regional climates.
The orographic effect explains why one side of a mountain gets more precipitation than the other.
What are seasons and what causes them?
The tilt of the Earth in relation to the sun is what causes the seasons. The seasons are spring, summer, fall, and winter and the transitions consist of a spring equinox, a summer solstice, a fall equinox, and a winter solstice.
Be able to name and briefly describe the eight major biomes
Tropical forest - closed canopy of trees throughout year, multiple layers of vegetation, lots of plant life Macchio (chaparral) - shrubs and grasses, seasonally dry conditions (drought) Savanna - trees and grassland, fires happen often Steppe - cover of different grasses Taiga (boreal forest) - coniferous forest, cold temps Desert - large sand dunes, sparse plant life, plants need to be able to retain moisture well in order to survive Temperate forest - deciduous trees Tundra - dwarf shrubs and some grasses, high wind, cold temps
Distinguish between climate and weather.
Weather refers to day to day changes while climate refers to an average of weather.
