Q2 Environmental Science Exam Study Guide

nitrogen cycle

Key processes include nitrogen fixation, nitrification, assimilation ammonification, and dentrification

Carbon Cycles

Emphasis on biological (photosynthesis/respiration), geological (sedimentation, fossil fuels), and anthropogenic (burning fossil fuels) processes.

Water (Hydrologic) Cycle

Processes include evaporation, condensation, precipitation, infiltration, runoff

Phosphorus Cycle

Unique in that it doesn't typically have an atmospheric component.

Carbon Sequestration

The process of capturing and storing atmospheric carbon dioxide, such as in forests, soils, or geological formations

Producers

Organisms that make their own food usually through photosynthesis (mostly plants/ algae)

Consumers

Organisms that eat other organisms (Herbivores/Carnivores)

Herbivores

Primary consumers that eat producers.

Carnivores

secondary/tertiary consumers that eat other consumers

Decomposers

Organisms (bacteria, fungi) that break down dead organic matter and waste, recycling nutrients.

Detritivores

Organisms (worms, insects) that feed on detritus (dead organic material)

Photosynthesis

Photosynthesis creates glucose and oxygen from CO2, water, and sunlight

Cellular respiration

Uses glucose and oxygen to release energy, producing CO2 and water

Biosphere

Zone of Earth where life exists (all living things)

Geosphere

Solid earth (rocks, mineral, land)

Atmosphere

Gaseous envelope surrounding earth

Hydrosphere

All water on earth (liquid, solid, gas)

Biotic

Living components of an ecosystem

Abiotic

Non-living components (e.g. , sunlight, water, soil, temperature)

Positive feedback

Loop that amplifies or strengthens an initial change (e.g., melting ice -> less reflection -> more warming -> more melting)

Negative feedback

Loop that counteracts or dampens an initial change, stabilizing the system (e.g., predator-prey cycles, body temperature regulation).

Hydrologic and Nutrient Cycling

The continuous movement of water and nutrients through the environment

Terrestrial Ecosystem vs Aquatic Ecosystems

Review the fundamentals differences in how energy flows, habitats are structured, and challenges faced by organisms in land vs water environments.

Tragedy of the Commons

This principle, discussed by Garrett Hardin, describes hoe shared, finite resources (commons) are often overused and depleted because individuals act in their own self-interest, rather than for the collective good. The inevitable result is the destruction of resources for everyone.

Principle of Sustainability

Focuses on meeting the needs of the present without compromising the ability of future generations to meet their own needs. It involves living within the limits of Earth's natural system.

Ecology

The study of the relationships between living organisms and their environment.

Natural capital

This refers to the world's stock of natural resources (geology, soils, air, water, living organisms) that provide essential good and ecosystem services underpinning the economy and society

Renewable Resources

Resources that can replenish naturally on a human timescale, such as timber, fresh water, and solar, wind, and geothermal energy

Inexhaustible Resources

Resources that are perpetually available like solar energy

Nonrenewable Resources

Resources that exist in a fixed amount or are depleted faster that they can be replaced by natural processes (e.g., fossil fuels. minerals, metal ores)

Point Sources

Single, identifiable sources of pollution, such as a factory smokestack, a sewage treatment plant discharge pipe, or an oil spill from and specific tank

Non-point Sources

Diffuse contamination from large areas, difficult to trace to a single origin (e.g., agricultural runoff, urban stormwater runoff, wind-borne pollutants)

Ecological Footprint

A measure of the total area of a functionally productive land a marine ecosystem required to produce the resources a population consumes and to assimilate the waste that population generates

Water Pollution

Contamination of water bodies, typically by human activities, which negatively affects their uses.

Causes of Environmental Problems

Factors such as population growth, unsustainable resource consumption (affluence), poverty, undervaluing natural capital, and the isolation from nature are common underlying causes