Lecture 1 - Ecology and the Biosphere

Explain how the Earth’s round shape, its 23.5° tilt on its axis, and its annual rotation around the sun are responsible for the seasons and the gradient in temperature between the equator and the N and S poles.

Sphere shape —> sunlight naturally hits the equator directly

Tilt —> Means one hemisphere leans more toward the sun (summer) and one leans away (winter)

Rotation —> Causes day and night, varying length during seasons

Name the three factors that cause phytoplankton levels to be highest along coastlines and in the N and S poles.

1. Abundant sunlight for photosynthesis/growth

2. High nutrient delivery via upwelling

3. Favorable physical conditions like cooler temperatures

Predict which terrestrial biome(s) is (are) likely to occur under a given set of environmental conditions (i.e., mean annual temperature and precipitation).

Discuss how local features of the environment (e.g., large mountain ranges along the coast) can influence climate.

• Orographic precipitation (moist air from the ocean hits the windward side, rises, condenses into clouds, and causes rain/snow)

• Rain shadow effect (air descends the leeward side and air warms and dries out, creating desert)

Distinguish the freshwater habits in terms of the presence of emergent vegetation, presence of aphotic zones and moving water.

Lakes and Ponds (Standing Water) = near the shore, only in deep ones, little movement

Rivers and Streams (Running Water) = few, generally absent, constant movement

Wetlands = abundant, absent, slow

Distinguish the neritic, oceanic, and abyssal zones of the oceans.

Neritic: shallow, sunlit water over the continental shelf

Oceanic: open ocean beyond the shelf

Abyssal: deep-ocean floor and water column

Explain why the water in estuaries and marine biomes is salty.

Rain erodes rocks on land, carrying dissolved salts into the sea where it evaporates and is left behind to accumulate