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GEOG 204 Lecture Notes
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The document consists of notes taken from attending Professor John Buskard's lectures and it includes the most important parts of the material.
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GGH1502 - EXAM PACK (2022)
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GGH1502 - EXAM PACK (2022)
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GGH1502 semester 1&2 Assignment 2 2021
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There have been 5 mass extinctions (wiping out a certain species off the planet) and a6th one is guaranteed
Environmental Consequences
Result of:
1. Unintended consequences
a. Acid rain, ozone depletion, climate change
i. Ozone is getting thinner because of the gases we create
ii. Acid rain caused by the burning of fossil fuels
2. Conscious manipulation
a. Deforestation, hydro dams, agriculture
Chapter 1 – Studying Geography
An Indiographic Discipline
To understand the meaning of contingent, accidental, and often subjective
phenomena
Geography is divided into two realms
Physical Geography
o Biogeography, hydrology, climatology, geology, etc.
Human Geography
o Political geography, cultural geography, demography, population
geography, economic geography, etc.
Environmental Geography
Deals with the space where the two major divisions meet
Scientific method is crucial in good decision making
o Allows some scientific rigor in what was traditionally a qualitative and
eco-centric approach to conservation
Often allows for the participation of stakeholders (public) in the process
Physical Environment
Living (biotic) and non living (abiotic) components
Four spheres:
1. Lithosphere
a. Thin crust, outer layer of the mantle
b. Made up of a series of plates
2. Atmosphere
a. The gases that make up the air around us
i. Fixed gases
1. Exist in the same concentration everywhere on the
planet
ii. Variable gases
1. The will exist on different concentrations depending on
where you’re located on the planet
2. Most important variable gas is water vapour
3. Biosphere
a. All living things
4. Hydrosphere
a. The combined sources of water on the planet
, i. Three forms: Gas, Liquid, Solid
ii. Driven by the hydrological cycle
Ecosystems
A suite of environmental characteristics that combine in a particular area or region
Also known as biomes
Often classified by levels of productivity
o Productivity affected by three things
Availability of nutrients
Climate
Diversity of species the number of different species
Classification
1. Tundra
a. Considered the least productive biomes in the world largely because of
its climate and its diverse species
2. Coniferous Forest
a. Becoming a little more productive
3. Temperate Forest
a. Canada…
4. Tropical Rain Forest
a. Equator
5. Tropical Savanna
a. Between equator and temperate
6. Temperate Grassland
7. Desert
a. One of the least productive because it doesn’t have a lot of nutrients
and not much of a diverse species
8. Maquis
a. Mediterranean shrub land
These are all combinations of temperature and precipitation
Natural cycles
Chemical and biological reactions – manifested in physical changes
Eg. Carbon cycle
o Major stores of carbon are the oceans and the rocks
o Minor stores of carbon are the atmosphere and living organisms
o Carbon is stored in two processes: Sedimentation and Photosynthesis
o Carbon is stored for different periods of time. The longest trees will
live about 100 years. Hydrocarbons, on the other hand, are stored for
millions and millions of years
Food Chains
Conversion of solar energy through living organisms
Hierarchical – trophic levels
o Each level is called a trophic level
It is rocket science! – 2 laws of thermodynamics
o 1. Energy is neither created nor destroyed, it is simply converted from
one form to another
, o CRUCIAL ONE: 2. In every conversion there is a loss of potential
energy
5 Characteristics of the food chain
1. At each level, potential energy is lost
2. Animals are bigger at each successive trophic level
3. Number of individuals decreases
4. Human actions have huge impacts on the food chain
5. Actions in one part of the cycle will affect all other parts of the cycle
Solar energy is source of all nutrients
o Converted to chemical energy in plants – producers
o Producers are eaten by 1st order consumers – herbivores
o Herbivores are eaten by 2nd order consumers – Carnivores and
Omnivores
Plants Animals Humans Zombies
As China and India continue to industrialize more energy
May create shortages everywhere and the search for alternatives
More land producing fuel crops instead of food crops =
o Rising food prices for all
o More hunger for the poor
Equilibrium
Dynamic vs. fixed… Equilibrium is not fixed, it is dynamic
Ecosystems are not constant or fixed, they are constantly changing; they have
established a dynamic equilibrium
Balance is achieved through interactions of biotic and abiotic components
GAIA Hypothesis – Earth is self regulating and establishes this equilibrium…
Humans are disturbing the Earth’s equilibrium
A Matter of Scale
Time Scales
Enviro changes – wide range of time scales
Long term changes (eg. Tectonics) can have very short term impacts
(earthquakes, volcanic eruptions)
Humans – upset long established equilibriums
Short term negative impacts vs. long term positive impacts
o For instance: forest fire. A forest fire is something that happens on a
very short time scale and has a lot of negative impacts associated with
it. What might be a long-term positive impact of that forest fire? The
fire releases the seeds that are in the trees and thus seeds fall to the
ground and the trees sprout back up again. It is like a fresh start. The
problem now is we always put out forest fires because we humans live
there. We are trying to change how mother nature benefits.
Feedbacks
Positive
Enhance original effect
, Upset equilibrium
o So we got equilibrium in place, a positive feedback will cause upset
and disturb that equilibrium
Negative
Dampen original effect
Seek to maintain or restore dynamic equilibrium
o In a warming world there will be more evaporation from the oceans
thus leading to more clouds and blocking the sun from getting in. Also,
more plant growth; since plants take CO2, more CO2 will cool things
down.
Positive vs. Negative: Not about how good or bad it is…: Does it increase the effect
or does it decrease?
Clouds can be both a positive and a negative feedback of climate change. They can
cool things up by blocking the sun or they can produce heat because of the sun
Thresholds
Represents points at which change may be induced
Often can be irreversible
o Once you cross a threshold it is impossible to go back
Crossing a threshold is a function of:
o Frequency
Example: overcultimation with field. If you grow crops without
time for nutrients to rebuild in the soil after removing the crops,
the soil will not grow anything. So it’s how many times you
remove the crop from the land… that’s the frequency. Because
you removed it so many times you crossed the threshold
o Intensity
Tornadoes or hurricanes have to do with heat. The warmer the
waters the more likely a hurricane will occur; same thing with
tornadoes but with land temperature
o Cumulative impacts
Heavy snow fall in cold temperatures wont result in an
avalanche, however, heavy snow fall in warm temperatures will
result in an avalanche
Gradual and catastrophic changes affect environs
o Things like tectonic plates are gradual changes but earthquakes,
tornadoes, hurricanes are much more catastrophic changes
Cont’d
- Inertia: Ecosystems’ ability to resist disturbances
Can be affected by a number of things
- Resilience: ability of an ecosystem to return to its original state after being altered or
disturbed
- Ecosystems can have low inertia and high resilience, or any combination thereof
- Ecosystems that have high inertia and high resilience have the greatest stability
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