Deep Time, Population Ecology & Environmental Impacts

Vocabulary flashcards covering key concepts from lecture notes on Earth's deep time, population ecology, biomes, and the nitrogen cycle, with a focus on definitions and factual recall.

Age of Earth

Approximately 4.5 billion years.

Dinosaur extinction

Occurred approximately 65 million years ago.

End of last ice age

Approximately 12,000 years ago.

Limestone

A rock formed from shells/calcium carbonate in oceans.

Sandstone

A rock formed from compressed sand grains.

Mudstone

A rock formed from compacted clay/silt.

Erratics

Boulders moved by glaciers during ice ages.

Reindeer on St. Matthew Island

An example of unchecked exponential growth overshooting carrying capacity, leading to a population crash.

Rabbits in Australia

An example of an invasive species experiencing exponential growth and causing ecological disaster.

Exponential growth

Rapid growth characterized by a J-shaped curve and a growth rate proportional to population size.

Doubling Time (DT)

The time it takes for a population to double, calculated approximately as 70 divided by the growth rate (r) as a percentage.

Carrying capacity (K)

The maximum population size an environment can sustain.

Age pyramid (wide base)

Indicates a growing population.

Age pyramid (narrow base)

Indicates a shrinking population.

Age pyramid (even distribution)

Indicates a stable population.

Tundra

A major biome type.

Boreal forest (Taiga)

A major biome type, also known as Taiga.

Chaparral

A biome characterized by mild wet winters, dry summers, and shrubs.

Temperate rainforest

A biome characterized by thick forests, found in areas like Washington/British Columbia.

Savanna

A biome characterized by grasslands with clusters of trees.

Atmospheric Nitrogen (N₂)

A form of nitrogen that plants cannot directly use; they require nitrate or ammonium.

Nitrogen fixation

The process of converting atmospheric nitrogen (N₂) into usable ammonia (NH₃), performed by bacteria or industrial processes like Haber-Bosch.

Eutrophication

A process where excessive nutrient runoff leads to algal blooms, subsequent decomposition, and depletion of oxygen, causing dead zones.

Dead Zone Gulf of Mexico

An area of hypoxia (low oxygen) caused by fertilizer runoff via the Mississippi River, leading to algal blooms and oxygen depletion.

Impact of upstream human activity

Actions in one part of a country can significantly affect ecosystems and people far away, such as fertilizer runoff impacting distant waters.