Untitled Flashcards Set

Ecologists ask question about the natural world that can include organisms and their abiotic surroundings

·      Ecologists must examine as large as entire biosphere to as small as a single individual.

·      (Make sure to understand college-level evolution—will appear on exams)

Difference btwn weather and climate

·      While short-term variation in temperature and precipitation is “weather”, annual patterns describe “climate”

·      Climate is what an area generally experiences routinely, while weather is an individual event

Global Trends

Clouds and surface structures absorb solar radiation and reflect it back, which causes the Greenhouse Effect

The energy that maintains Earth’s climate is primarily solar

·      The sun strikes the thermal equator (the Firebox) directly (90-degree angle) causing warm air to rise

·      This in turn creates currents of air and rain.

·      Hadley Cell: causes predictable patterns of weather from 0-degrees to 30-degrees latitude—sun strikes earthly directly

o   Hot air balloon: hot air expands and density lowers, causing it to rise

o   Similar process at equator while Hadley cells

o   Hot air at equator rises and is pushed by hot air below it

o   Eventually, hot air reaches point in atmosphere where it cools and returns to earth, repeating the cycle

o   Warm air holds more water compared to cold air—more dense.

o   When it starts to condense, the water is squeezed out, causing rainfall

o   As air comes closer to earth surface, it is cold and dry—sucks moisture out of other things. This results in the creation of the major deserts.

Intertropical Convergence Zone: Tradewinds, allowed ships to reliably reach the new world from Africa and Europe

Hadley and Ferrell Cells create predictable precipitation and temperature zones.

Ferrel Cells: are what

·      When Hadley Cells goes through its process, it drags air from other regions of earth

·      Vacuum created by Hadley cells, second set of circulating cells

Polar Cells- near the poles, weakly circulate at 60-90 degrees

The range of daylength with changing latitude affects growing seasons and plant community structure

The tilt of the earth relative to the sun determines the intensity of sunlight and the seasons

·      As the earth rotates around the sun, sometimes it leans towards or away from the sun, creating the seasons

Greatest extremes in daylight are found at the polar (90 degree) latitude

·      Sun never goes below the horizon during the summer.

·      Sun never clears horizon during the winter

·      The farther you are from the equator, the more extreme amount of sunlight there is.

The Coriolis Effect- causes a deflection in air movement because of the Earth’s rotation

·      Takes west coast 3 hours to where the East Coast currently is

·      Air has moved east while coming down

·      If you threw a ball up into the air, it would land west instead of in a straight line because of the earth’s rotation

·      Earth rotates east.

Night is winter of tropics—12 hours of sunlight every day in Caribbeans

Lecture 2—1/13/25

Biomes are major communities of plants and animals and are determined by both climate and weather factors

Similar environmental conditions can cause convergent evolution—no common ancestor, similarities caused purely by conditions

·      Ex: Organ pipe cactus—Arizona, and Euphorb—Namibia (Africa). Aridness created similar structure.

o   Needle-structure has less surface area, causes less water to evaporated

·      Ex: Birds and Bats—both fly, but are not closely related at all

·      Convergent: organisms encounter the same problem and evolve similar structures to solve that problem. Same phenotypes

Terrestrial areas can be sorted into 4 or 5 general categories based on temperature and water availability*

1.     Snow/Polar

2.     Temperate—seasonal: hot in summer to cold in winter

3.     Equatorial—equator:

4.     Arid

·      *Frozen water is unavailable for use in photosynthesis

Biomes are defined by dominant plant growth forms, which are turn restricted by temperature and water availability patterns

(Look at Week 1 handout for questions)

1.     Why are forms of plants more responsive to variations in climate than the forms of animals?

a.     Animals can escape their environment if the environment is too hot or cold. Plants, comparatively, cannot move or hide (need sun for photosynthesis), so they need to be adapted for where they are.

Climate graphs chart the annual cycles of rain and temperature that predict growing seasons

·      Lower line indicates the limiting factor—temperature and precipitation

Climographs allow us to predict what types of organisms will be found in a given area

·      Ecuador vs. Finland

o   Ecuador: Hadley cell, steady rain since it is close to the equator, and 12 hour day

o   Finland: Polar cells, adaptation due to less consistent rain. Animals adapted to less rainfall and smaller trees

Precipitation refers exclusively to liquid precipitation, not snow

·      Results in triangular shape of Whittaker’s diagram

Why do deserts not burn?

·      Nothing to burn, environment is adapted to hot and dry environment already

Climate graphs for boreal and temperate forests demonstrate similar patterns but differ in actual water and temperature averages

·      For boreal, lots of water available, but still temperature limited

·      For temperate, lots of water available and warm temperature in the summers. Longer growth period

Local features like mountains or large bodies of water, have an effect on biome chirographs

·      Water can absorb heat, cold water is less dense than ice

Mountain ranges perpendicular to prevailing winds create rain shadows that determine species distribution within communities

·      Like a mini Hadley cell, mountains pick up wind over water.

·      Moist air comes from ocean, meets the mountains, and it begins to rain. Cool and dry air eventually crosses over to other side and has no rain—becomes a drying wind

o   One side gets more rain than expected, the other gets less and becomes a desert

·      Seen in Pacific Northwest

·      Although Hawaii is located within the tropics, local geographic features create rain-shadow effects

Because of local geographic factors, several

Water-based communities are described as aquatic ecosystems

Aquatic Ecosystems are categorized by their proximity to sunlight and nearness to shore

·      Distance to sun determines photosynthetic organism

·      In lakes, profundal zone is where sunlight cannot reach—organisms live there, but they typically live off of corpses of others.

·      Littoral Zone refers to area right next to lake

·      Ocean divided into

o   Photic Zone

o   Aphotic Zone

o   Abyssal Zone—deepest part of the ocean

The insulating effect of large bodies of water also mitigates seasonal temperature changes.

·      Oceans do not freeze—salt water less likely to freeze

Seasonal changes allow mixing to occur in temperate lakes—this is known as lake turnover

·      Thermocline in summer divided between epilimnion and hypolimnion

·      Thermocline- point at which temperature in water changes rapidly

·      During fall, hypolimnion expands, and winds churn water—good thing, makes more nutrients available

·      In winter, there is no thermocline—consistent temperature all the way through

·      In spring, mixing occurs again—fuels growth in summer

·      Turnover occurs in spring and fall