Ch. 2 The Physical Environment Flashcards
Salmon are anadromous, which means..
They return to streams from the ocean to spawn in natal streams
Many threats to streams have decreased migrations, spawning and reproductive success of salmon..
- damming
- pollution
- sedimentation
- overfishing
The ___ ___ ultimately determines where organisms can live, and the resources that are available to them.
Physical environment
___ is the most fundamental characteristic of the physical environment.
Climate
Weather -
Current conditions: temperature, precipitation, humidity, cloud cover
Short-term
Climate -
Long-term description of weather, based on averages and variation measured over decades
Climatic variation includes..
- daily and seasonal cycles
- large-scale cycles that occur over years or decades
Long-term climate change can be a result of..
Changes in the intensity and distribution of solar radiation and changes in overall energy balance
Current climate change is due to..
Significantly increased CO2 and other gases in the atmosphere due to human activities
Climate determines the ___ ___ of organisms.
Geographic distribution
Climate is characterized by average conditions, but extreme conditions are also important to organisms as they contribute to ___ and ___.
Stress and mortality
The physical environment must be characterized by its ___ ___ ___, as well as average conditions.
Variability over time
___ affects abiotic processes.
Climate.
The ___ is the ultimate source of energy that drives global climate.
Sun
An __ __ accounts for balance of gains and losses.
Energy budget
Energy is transferred by four pathways:
Conduction
Convection
Radiation
Evaporation
Conduction -
Kinetic energy transfer by molecules in direct contact with one another
Convection -
Energy transfer by movements of fluids
Radiation -
Energy transfer by electromagnetic radiation
Evaporation -
Heat loss from a surface by evaporation of water
Much of the solar radiation absorbed by earths surface is re-radiated back to the atmosphere as ___ ___.
Infrared radiation
Latent heat flux
Water at surface evaporates -> absorbs energy
____ includes evaporation and transpirational loss by plants.
Evapotranspiration
Sensible heat flux -
Energy transfer from warm air immediately above surface to cooler atmosphere by convection and conduction
Atmosphere contains ___ ___ that absorb and reradiate infrared radiations emitted by earth.
Greenhouse gases
Greenhouse gases
Water vapor
Carbon dioxide
Methane
Nitrous oxide
Natural ___ ___ is a very good thing for life on earth.
Greenhouse effect
Without greenhouse gases, earths climate would be about ___ cooler, near freezing.
33C
Winds and ocean currents result from differences in ___ ___ across the surface of earth.
Solar radiation
Uplift -
Warm air is less dense than cool air, and it rises
Subsidence -
- air descends when it cools and forms a high pressure zone at about 30 degrees N and S
- major deserts of the world are at these latitudes
Equatorial uplift creates a large-scale, three-dimensional pattern of atmospheric circulation known as a ___ ___.
Hadley cell
___ ___ exist at mid-latitudes.
Ferrell cells
The ___ ___ occurs at north and south poles - high pressure zones with little precipitation - “polar deserts”
Polar cell
The three cells result in the three major climatic zones in each hemisphere:
Tropical
Temperate
Polar
Areas of high a low pressure created by circulation cells result in air movements called ___ ___.
Prevailing winds
Winds are deflected to the right in northern hemisphere and to the left in the Southern Hemisphere due to the ___ ___.
Coriolis effect
Water has higher ___ ___ than land.
Heat capacity
Heat capacity -
Amount of energy required to raise a given quantity of matter a specific amount of temperature
Bermuda high
Helps steer hurricanes toward the north in the summer months
What is the Coriolis effect and how does it affect winds and currents?
Major ocean surface currents are driven by surface winds, modified by the coriolis effect
Downwelling -
Where warm tropical surface currents reach polar areas, the water cools, ice forms, the water becomes more saline and more dense and sinks
Upwelling -
Where deep ocean water rises to surface
- occurs where prevailing winds blow parallel to coast
- upwellings influence coastal climates and bring cold nutrient-rich waters to the surface
Upwellings bring nutrients from deep sediments to the ___ ___.
Photic zone
Photic zone -
Where light penetrates and phytoplankton proliferate
The “great ocean conveyer belt” -
An interconnected system of deep ocean currents that link pacific, Indian, and Atlantic oceans
Lapse rate -
Atmospheric temperature decreases with increasing elevation/altitude
Hadley, Ferrell, and polar circulation cells suggest that..
Precipitation should be highest in the tropical latitudes and in a band at about 60 degrees N and S; and lowest in zones around 30 degrees N and S.
Proximity to oceans, mountain ranges, and regional topography influence regional climate, which influences ___.
Vegetation
Vegetation in turn affects ___ ___.
Regional climate
Coastal areas have what type of climate?
Maritime climate
Areas in the center of large continents have ___ ___ -> much greater variation in daily and seasonal temperatures.
Continental climate
Orographic precipitation -
When an air mass meets a mountain range, it is forced upwards, cooling and releasing precipitation
Slope aspect -
Direction the slope faces
Rain shadow:
- north-south trending mountain ranges create rain shadow
- slope facing prevailing winds receivers high precipitation, while leeward slope gets little precipitation
- rain shadow effect influences vegetation
Albedo:
- capacity of land surface to reflect solar radiation - is influenced by vegetation type, soils, and topography
Example: a coniferous forest has a darker color and lower albedo than bare soil or a dormant grassland
Evapotranspiration -
- sum of water loss through transpiration by plants and evaporation from soil
- transfers energy and water into atmosphere, thereby affecting air temperature and moisture
Loss of alteration of vegetation can affect ___.
Climate
___ increases albedo of land surface, lowering absorption of solar radiation and resulting in less heating.
Deforestation
Seasonal and long-term climatic variation are associated with changes in the earths…
Position relative to the sun
Earth is tilted at an angle of ___ relative to the suns direct rays.
23.5 degrees
In the tropics, seasons are marked by changes in ___.
Precipitation
Intertropical convergence zone (ITCZ) -
Zone of maximum solar radiation and atmospheric uplift
Tampico -
Rainy season in northern hemisphere summer-fall
Vicosa -
Rainy season in Southern Hemisphere summer-fall
___ environments also experience seasonal changes in temperature.
Aquatic
Water is most dense at ___ degrees C.
4
Ice has a higher ___ than open water.
Albedo (reflectance)
Ocean and lakes can become stratified -
Warm surface water on top of colder, denser water results in layers that do not mix
Thermocline -
Zone of transition
In summer, stratification is most intense ->
Warm epilimnion lies over colder hypolimnion
In spring and fall ->
Complete mixing (turnover) occurs when water temperature and density become uniform with depth
North Atlantic oscillation -
Similar atmospheric pressure - ocean current oscillation that affects climate in Europe, northern Asia, and the eastern coast of North America
Pacific decadal oscillation and Atlantic multidecadal oscillation -
Affects climate in North Pacific and Atlantic, and in US in opposing directions
Happened over millions of years
We are currently in an ___ period.
Interglacial
Milankovitch cycles -
- regular changes in shape of earths orbit and tilt of its axis relative to the sun
- the intensity of solar radiation reaching earth changes, accentuating seasonal variation and resulting in climatic change
___, ___, and ___ concentrations are major determinants of the chemical environment.
Salinity, acidity, and oxygen
Salinity -
Concentration of dissolved salts in water
Salinization -
Soils in arid regions become saline when water is brought to the surface by plant roots or irrigation
Acidity -
Ability of a solution to act as an acid
Alkalinity -
Ability of a solution to act as a base
Except for some archaea, bacteria, fungi, most organisms require ___ for their metabolic processes.
Oxygen
Research on salmon production led to the discovery of the ___ ___ ___.
Pacific decadal oscillation
Two aspects of the PDO are particularly significant in the context of ecology:
- Relationship between climate, the functioning of organisms and their growth and reproduction, and population and community processes
- time scale of the PDO is long
Disturbance -
An event that detrimentally affects some species populations
