Chapter 1 and Chapter 2

What is ecology?

The scientific study of interactions between organisms and their environment

What is environmental science?

An interdisciplinary field of study that incorporates concepts from the natural sciences (including ecology) and the social sciences (e.g., politics, economics, ethics), focused on how people affect the environment and how we can address environmental problems.

How do ecologists view the balance of nature?

Ecologists now recognize (1) that natural systems do not necessarily return to their original state after a disturbance and (2) that random effects often play important roles in nature.

What is the individual level of ecology?

• Organismal biology

• Investigation of individual response

What is a population and what is the population level of ecology?

• Single species response

• Population demography

  • Birth rates

  • Death rates

  • longevity

• A group of individuals of the same species that live within a particular area and interact with one another

What is a community and what is the community level of ecology?

• A group of interacting species that occur together at the same place and time.

• Multiple interacting species responses

• Winners and losers

• Changes in community composition

What is a ecosystem and what is the ecosystem level of ecology?

• All the organisms in a given area as well as the physical environment in which they live; an ecosystem can include one or more communities.

• Response of whole ecosystems

• Energy and Nutrient fluxes

  • Changes in productivity

  • Inputs and outputs of energy or nutrients

    
    

What is the scientific method?

An iterative and self-correcting process by which scientists learn about the natural world, consisting of four steps:

(1) observe nature and ask a question about those observations

(2) develop possible answers to that question (hypotheses)

(3) evaluate competing hypotheses with experiments, observations, or quantitative models

(4) use the results of those experiments, observations, or models to modify the hypotheses, pose new questions, or draw conclusions.

What is the definition of weather?

The temperature, humidity, precipitation, wind, and cloud cover at a particular time and place

What is the definition of climate?

The long-term description of weather at a given location, based on averages and variation measured over decades.

How are organisms distributed geographically?

The geographic distributions of organisms are influenced by extreme conditions more than average conditions because extreme events are important determinants of mortality

How are physical environments characterized by weather?

The physical environment must also be characterized by its variability over time, not just by average conditions

Where is the energy for global climate derived from?

The energy that drives the global climate system is ultimately derived from solar radiation

When the sun radiates energy, what absorbs the radiation?

• Atmosphere (ozone, clouds, and water vapor)

• Surface

What re-emits solar radiation?

• Much of the solar radiation absorbed by Earth’s surface is emitted to the atmosphere as infrared radiation (also known as longwave radiation)

• Earth’s surface also loses energy and is cooled when water evaporates, because the change in phase from liquid water to water vapor absorbs energy

What is latent heat flux?

Earth’s surface also loses energy and is cooled when water evaporates, because the change in phase from liquid water to water vapor absorbs energy.

What is conduction, convection, and sensible heat flux? How does it play into energy transfer?

• Conduction: The transfer of sensible heat through the exchange of kinetic energy between molecules due to a temperature gradient

• Convection: The transfer of sensible heat through the exchange of air and water molecules as they move from one area to another

• Sensible Heat Flux: The transfer of heat through the exchange of energy by conduction or convection

• Energy is also transferred through the exchange of kinetic energy by molecules in direct contact with one another (conduction) and by the movement of currents of air (wind) and water (convection)

How does the atmosphere play into Earth’s energy?

• The atmosphere absorbs much of the infrared radiation emitted from Earth’s surface (and from clouds) and reradiates it back to Earth’s surface. This reradiation represents a major energy gain. The atmosphere contains gases that absorb and reradiate infrared radiation.

What causes the global climate patterns?

• Toward the poles, the sun’s rays are spread over a larger area and take a longer path through the atmosphere. The amount of atmosphere the rays must pass through increases toward the poles, so more radiation is reflected or absorbed before it reaches the surface.

• Near the equator, the sun’s rays strike Earth’s surface perpendicularly

Explain uplift and how atmospheric pressure create latitudinal patterns

• Warm air is less dense than cool air, so the air above the warm surface rises

• As the warm air rises, it expands and cools due to low atmospheric pressure

• As the air cools, water vapor condenses to form clouds

How are zones of high pressure and low pressure formed?

• The uplift of air in the tropics creates a band of low atmospheric pressure relative to zones to the north and south

• The uplift of air in the tropics creates a band of low atmospheric pressure relative to zones to the north and south

• Eventually, this poleward-moving air cools as it exchanges heat with the surrounding air and meets cooler air moving from the poles toward the equator. Once the air reaches a temperature similar to that of the surrounding atmosphere, it descends toward Earth’s surface, a process known as subsidence.

• Subsidence creates regions of high atmospheric pressure around latitudes 30°N and S, which inhibit the formation of clouds. Thus Earth’s major deserts are found at these latitudes.

What are Hadley, polar, and Ferrell cells?

• Hadley- A large-scale, three-dimensional pattern of atmospheric circulation in each hemisphere in which air is uplifted at the equator and subsides at about 30°N and S

• Polar- A large-scale, three-dimensional pattern of atmospheric circulation in which air subsides at the poles, moves toward the equator when it reaches Earth’s surface, and is replaced by air moving through the upper atmosphere from lower latitudes. Subsidence at the poles creates an area of high pressure, so the polar regions, despite the abundance of ice and snow on the ground, actually receive little precipitation and are known as polar deserts.

• Ferrell- A large-scale, three-dimensional pattern of atmospheric circulation in each hemisphere, located at mid-latitudes between the Hadley and polar cells

How do winds move on Earth?

• Winds flow from areas of high pressure to areas of low pressure. Thus, the areas of high and low pressure formed by atmospheric circulation cells give rise to consistent patterns of air movement at Earth’s surface, known as prevailing winds.

• the prevailing winds appear to be deflected to the right (clockwise) in the Northern Hemisphere and to the left (counterclockwise) in the Southern Hemisphere (Coriolis Effect)

What is the differences in temperature between water and land? How does this effect prevailing winds?

• Water has a higher heat capacity than land, so it absorbs and stores more energy with less temperature change than land. For this reason, the land surface warms up more than ocean water in summer, but in winter the oceans retain more heat, and thus remain warmer, than land at the same latitude. As a result, seasonal air temperature changes are less extreme over the oceans than they are on land.

• In summer, air over the oceans is cooler and denser than that over land, and semipermanent zones of high pressure (high-pressure cells) form over the oceans, particularly around 30°N and S. In winter, the opposite situation exists: the air over the continents is cooler and denser than that over the oceans, so high-pressure cells develop in the temperate zones over large continental areas. Because winds blow from areas of high pressure to areas of low pressure, these seasonal shifts in pressure cells influence the direction of the prevailing winds.

Which way do ocean surface currents move?

• The pattern of ocean surface currents is similar to, but not identical to, the pattern of prevailing winds

What are zones of downwelling and upwelling?

• Downwelling- The sinking of deep ocean water from the surface

• Upwelling- The rising of deep ocean waters to the surface