Environmental Science + Ecosystems Flashcards
ESA Exam
1st Law of Thermodynamics
Conservation of Energy: Energy cannot be created or destroyed – it can only be transformed
2nd Law of Thermodynamics
The level of disorder constantly increases. The ability of energy to do work is decreased or lost after it is used. Entropy is the measure of the dispersement or randomness of energy (e.g. low quality energy).
Energy transformation can never be 100% efficient.
Phosphorus Cycle
Eroded from rocks, absorbed by plant roots, eaten by animals, released back into the environment through waste and decomposition. Also enters waterways, and eventually gets compacted into rock. Brought back millions of years later by geologic uplift.
Humans impacts: Overuse of phosphorus in fertilisers and detergents.
Implications? Depletion of resource; Limiting nutrient; Eutrophication.
Nitrogen Cycle
Nitrogen in the air–> Nitrogen uptake (converted to ammonium) –> Nitrification –>assimilation –>Ammonification–> Denitrification
Human impacts:
Increased amount of fixed nitrogen through fertilisers. Combustion of fossil fuels, releasing NOx.
Implications?
- Decreased biodiversity in enriched land;
- Contamination of groundwater;
- Runoff -> eutrophication;
- Acid deposition;
- Poor air quality.
Sulfur Cycle
Combustion of coal and oil. Extraction of (some) metals through smelting.
Implications? Creation of SO2 - (smog) > acid deposition -> Damage to ecosystems.
Carbon Cycle
Shifting of carbon from underground deposits through combustion of fossil fuels and deforestation.
Implications? Increased CO2 in the atmosphere (from preindustrial 0,029% to 0,04%); Climate change.
Hydrological Cycle
Release of aerosols through combustion. Release of GHG. Land use (for e.g. dams, irrigation).
Implications?
- Formation of aerosols -> alters cloud formation/precipitation patterns;
- Climate change -> ice-cap melting etc.; (Locally) altered patterns for water
infiltration/retention/evapotranspiration.
What is the only nutrient cycle without a biologically important gas element?
Phosphorus
What are 3 key components of biodiversity?
Species richness (# of species)
Genetic diversity (variety b/w populations)
Ecosystem diversity (variety of ecosystems on earth and of interactions b/w organisms)
What are the four physical realms?
Biosphere (living things), geosphere (geological processes), lithosphere (soils), and atmosphere (air)
What is an ecosystem?
All abiotic and biotic parts and interactions
Name six ecosystem services
Clean air * Clean water * Carbon storage * Storm protection * Food * Pollination.
What is energy, and how is it measured? What are the two basic types of energy?
The ability to do work, and it’s measured in Kilajoules (kJ). The two types of energy are potential and kinetic.
Factors that determine the abundance of a species in an ecosystem
- Abiotic factors: access to nutrients, shelter, etc.;
- Biotic factors: primary production (storing of energy), presence of predators, population density,
competition, etc
What is eutrophication and why is it problematic?
Eutrophication is the overgrowth of nutrients (often due to biogeochemical flows of nitrogen and phosphorus) in waterways, causing high BOD, and thus contributing to the die-off of marine and freshwater life, and ultimately dead zones.
