Lecture 1, Chapter 51 - Ecology & The Biosphere

Ecology

the scientific study of interactions between organisms + their environment

Terrestrial Ecosystems

• characterized by temperature and precipitation

• has the strongest effect on terrestrial (warm + wet, hot + dry)

Aquatic Ecosystems

• nutrient supply and light availability

• strongly shape where aquatic organisms live (dark, chemically rich vent)

Population

same species living in the same area

Community

population of different species in an area

Landscape

a mosaic (connected pieces) of connected ecosystems

Biosphere

the global ecosystem

Why do temperature + precipitation vary globally? (3 reasons)

1. light spreading causes temperature to decrease at higher latitudes (perpendicular vs oblique)

2. absorption from air molecules/clouds cause temperature to decrease at high latitudes

3. similar reason to #1, the tilt creates season (vernal + autumnal)

Precipitation Light

direct, less surface area to heat so it’s easier to heat (is hotter)

Oblique light

tilted, more surface area = harder because there is more area (less hotter)

Adiabatic cooling

a decrease in temperature without actual loss of heat energy

Tropical Seasonal Forest/Savana

same temperatures but demonstrate strong seasonality, of wet seasons and dry seasons (small leaved leaves scatter the landscape b/c fires happen easily; grass grow fast to cover the land)

animals: giraffes, elephants, zebras

location: equator and down of Africa, some South America)

Subtropical Desert

same + CONSISTENT temperatures but low precipitation (limits growth); low density, scattered vegetation

animals: camels, fennec foxes, coyotes

location: Northern Africa; deserts around 30 degree line on the map

Temperate Seasonal (Broafleaf) Forest

This is New York! Deciduous trees dominant = drop leaves in the winter. Temperature is generally the limiting resource. High competition (for sunlight, soil, etc)

animals: black bears, red foxes, raccoons, squirrels

location: Eastern United States & West Europe

Tropical Rainforest

high but consistent temperatures and high precipitation’ most limited by nutrients (water/temperature are NOT limiting)

animals: highest diversity among across all biomes (frogs, jaguars, sloth, toucan, etc)

location: South + Central America, Africa, some Southeast Asia/the Pacific

Tundra

severe polar climate; extremely cold temperatures and lack of trees
animal: polar bears, artic foxes, artic hare

location: encircling North Pole

Temperate Rainforest

high annual precipitation (often over 55 inches) and mild temperatures (39-54 degrees)

location: coastal regions (such as Pacific Northwest)

animals/plants: tall evergreen trees, abundant mosses, ferns, and lichens

Desert

extremely dry areas w/ minimal precipitation, featuring extreme temperature shifts)

Savanna

grasslands w/ scattered individual trees, experiencing distinct wet and dry seasons

Chaparral (Shrubland)

hot, dry summers and mild, rainy winters w/ dense-leaved shrugs and high fire risk

Freshwater Wetlands

characterized by nonflowing fresh water, shallow enough to have emergent vegetation

i.e. - swamps, marshes, bogs

Marine habitats

divided by light penetration and distance from shore

Salt Marshes + Mangrove Swamps

characterized by intertidal, estuarine waters w/ emergent vegetation

**estuarine waters = coastal regions where seawater mixes w/ fresh waters from rivers, streams, etc

Rocky Intertidal Zone

characterized by intertidal marine waters, on a step rocky coastline

coral reefs, seagrass beds, kelp forests are found in the neritic zone (shallow region of the ocean)

Open Ocean + Aphotic Zone

Earth’s largest biome (“garbage path”); includes microorganisms (bacteria + fungi) and larger invertebrates (crustaceans + polychaetae worms)

located in the benthic zone: the bottom surface of an aquatic zone → “marine snow”

True or False: ponds and lakes are characterized by nonflowing fresh water with areas too deep for emergent vegetation

True

NYC is a _____________ type of biome based on the average temperature and precipitation.

Temperate Seasonal Forest

Aquatic habitats are characterized by ____________ and _________ because of primary production

nutrients and light availability

Name some nutrients that would be a limiting factor in marine ecosystems

• nitrogen

• phosphorus/phosphate

• carbon

• sulfur

• iron

Photic Zone

upper layer in the ocean that receives sunlight and supports photosynthesis

Aphotic zone

this layer lies beneath the photic zone and extends to the ocean floor, in deep darkness where photosynthesis does not happen

Pelagic Province

the water

Benthic Province

the bottom sediments

What does the pelagic province include?

1. neritic one - shallow water above the continental shelves

2. oceanic zone - deep water beyond them

What does the benthic zone province include?

1. intertidal zone - shoreline that is submerged and exposed by tides

2. abyssal zone - the bottom sediments that lie permanently below deeper water