Chapter 3 - Biomes Flashcards
MODULE1-3:
(T) Terrestrial Biome :
Define biome
Are they considered ‘static’?
A biome is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader term than habitat and can comprise a variety of habitats (Source: Wikipedia)
(T) Biomes are a concept - the environment is more variable. Transitions between biomes are gradual ecotones, NOT sharp boundaries. Seasonality of rainfall and temperature affects biomes.
No, not static.
Can change due to:
* Precipitation
* Temperature
* Soil quality
* Disturbances
* Seasonality
!REFER TO FERRELL CELLS
QUIZ Q:
When climbing a mountain, we can observe transitions in communities and this is analagous to …
Biomes at different latitudes
MODULE 1-3
(T) Terrestrial Biome :
What climate factors determine where we find the various types of terrestrial biomes?
2-3 SENTENCES ABOUT EACH BIOME, HOW FORMED, MAYBE SOME PLANTS, LATITUDE, example maybe) CONNECT THE CLIMATE TO BIOME.
- Precipitation
- Temperature
- Soil Type (based on rates of decay, rates of nutrient loss, types of organic matter)
- Disturbances (either by wildlife or by natural fires)
- Seasonality
(T) Terrestrial Biome :
Why are there no cold AND wet places?
Is it temperature or precipitation that constrains maximum plant growth?
- Warm air rises and when it rises, it cools. When it cools, the moisture is dropped.
- Both, as well as soil and nutrients..
The picture below shows some useful info regarding temperature & precipitation:
MODULE 1-2:
(T) Terrestrial Biome :
How to read a Temperature and Precipitation graph?
Winnipeg: the orange line is the temperature. the histogram part is the precipitation.
MODULE 1-3:
(T) Terrestrial Biome :
What is the tree line?
How does precipitation limit the patterns of vegetation?
- the demarcation line where trees are unable to grow due to low temperatures AND lower levels of precipitation (basically, elevation)
- Elevation also ties into this: less precipitation limits up/down/around of plant – enough nutrients? enough sun? enough water? enough oxygen?
MODULE 1-3:
(T) Terrestrial Biome :
Explain how the biomes change as you move north from the equator. What is the pattern when you
climb to a higher elevation?
Is arctic tundra the same as alpine tundra?
- Temperature
- Soil Type
- Precipitation
- UV Radiation
- Sun exposure/amount
Desert, Grasslands especially are too dry to support trees (also, savanna’s & shrublands. Deserts can also be found in odd areas of the Earth due to ‘rain shadows’ and simply being near the equator.
QQ: REFER TO CELLS AROUND EARTH AT DIFFERENT LATITUDES. THE PATTERNS. 30 DEGREES. AIR CIRCULATION.
No, one is frozen wasteland and the other is pretty much the same, but with higher elevation
MODULE 1-3:
Soil :
Describe the typical composition of soil
Soil is a material composed of five ingredients — minerals, soil organic matter, living organisms, gas, and water (Source: nature.com)
MODULE 1-3:
(T) Soil :
PUT C & R together!
Clay is (-) and minerals are (+)
Retention of minerals depends on ______________.(clay)
Determines the cation exchange capacity of the soil.
* One teaspoon of soil contains approximately:
o 100 million bacteria
o 500,000 fungi
o 100,000 algae
o 50,000 protists
* Humus: dark partially decayed, complex
________________ matter. (organic)
o Holds water
* Soil profile: a sequence of horizontal layers
visible in the soil.
o These layers are called horizons (O, A,
B, C)
- O : dominated by organic material, consisting of undecomposed/partially decomposed plant materials, such as dead leaves.
- A : this topsoil is largely mineral soil developed from parent material. It’s organic matter leached from above giving it this distinctive dark colour
- B : this subsoil is the accumulation of mineral particles, such as clay and salts leached from the topsoil. It is distinguished based on colour, structure, and the kind of material leached from above. Partially broken down.
- C : this unconsolidated material is derived from the original parent material from which the soil developed. Unweathered parent material.
- R : bedrock. Unweathered parent material?
MODULE 1-3:
(T) Soil :
What causes weathering?
- Physical weathering (rain, water flowing, wind thermal expansion/constraction)
- Chemical weathering (reactions with gases, reactions OF H2O + minerals)
- Biological weathering (lichens, roots)
MODULE 1-3:
(T) Soil :
There are 5 main soil-forming processes that give rise to the diversity of soils and gives rise to the diversity of soils (think: how the soil is formed, how the climate affects it, how it affects the biome, how it affects organisms - only if specifically asked- WHERE & WHAT IS IT)
1st one: LATERIZATION
Laterization: a result of hot and rainy conditions that cause rapid leaching of rocks/minerals.
- “is the weathering process by which laterite is formed, and in the process, soils and rocks are depleted of soluble substances, such as silica-rich and alkaline components, and instead, soil is enriched with hydrated Al+ and Fe+ oxides”
- Where : tropical regions
- the water table is close to the surface, but the area will have pronounced dry seasons.
- Soils are acidic (ph 4-5) due to loss of cations except H+
-
Consequences: lack of agricultural opportunities, tree clearing leads to sandy area (no nutrient or H2O retention)
.
MODULE 1-3:
2nd one: CALCIFICATION
A result of evapouration and H2O uptake by plants – exceeding input by precipitation
- Alkaline salts (CaCO3) which are dissolved in the groundwater, move upwards and accumulate in the ‘B Horizon’. Will see a white layer between all the dark humus in the soil. Above it though, in the O & A layers, there will be rich, organic soil which will be dark in colour.
- Where: Grasslands
- Consequences : good agricultural opportunities, nutrient rich
MODULE 1-3:
3rd one: SALINIZATION
Leads to an accumulation of salts at or near the soil
surface. Similar to calcification, but this occurs in drier climates.
The Salinization Process Can occur when the water table is between two to three metres from the surface of the soil. The salts from the groundwater are raised by capillary action to the surface of the soil. This occurs when groundwater is saline (which is true in many areas), and is favoured by land use practices, allowing more rainwater to enter the aquifer than it could accommodate. For example, the clearing of trees for agriculture is a major reason for dryland salinity in some areas, since deep rooting of trees has been replaced by shallow rooting of annual crops
Causes of Salinization on the soil surface occurs where the following conditions occur together: * the presence of soluble salts (sulphates of sodium, calcium, magnesium) in the soil * a high water table * a high rate of evaporation * low annual rainfall Salinization often occurs on the rims of depressions and edges of channels, at the base of hillslopes, and in flat, low-lying areas surrounding shallow bodies of water. These areas receive additional water from below the surface, which evaporates, and the salts are left behind on the soil surface. Human practices that increase the soil moisture content (e. g. irrigation) increase salinization as the water moves through hillslope soil, accumulates in seeps and then evaporates.
Causes of Salinization Irrigation Almost all water (other than natural rainfall) contains some dissolved salts. Water is continually added through irrigation and lost from the soil through evapotranspiration and the salts that are left behind accumulate. Since soil salinity makes it more difficult for plants to absorb soil moisture, these salts must be leached out of the plant root zone by applying additional water. This, in turn, can lead to rising water tables, requiring drainage to keep the saline groundwater out of the root zone
Causes of Salinization Irrigation If the water table rises too high, then natural soil evaporation will begin to draw the salts back upward into the soil profile. The problem is accelerated when too much water is added too quickly due to inefficient water use: * applying more water than is required for leaching, * using bad estimates of evapotranspiration * poor drainage * use of saline water for irrigating agricultural crops. These practices result in the concentration of salts in the soil.
* Where : deserts…some grasslands
* Consequences : less agriculture possible, need to heavily irrigate or do drip irrigation, but tends to make soil even more salty
* root burn
MODULE 1-3:
4th one: PODZOLIZATION
Occurs in cool, moist climates where conifers dominate
* organic material from conifers creates strongly acidic conditions, which enhances leaching
* Cations, iron, & aluminum compounds removed from the A horizon
* Where : taiga (boreal forest)
MODULE 1-3:
5th one: GLEIZATION
Occurs in areas with high rainfall or poor drainage (low-lying areas)
* constantly wet soil slows decomposition of organic material
* organic soil –> acidic, so reacts with iron in the soil
* Where : boreal….sometimes tundra. (bogs occur here (wet + acidic conditions)
AQUATIC ECOLOGY:
Littoral and Limnetic Zones:
Aphotic (euphotic + disphotic) & Photic Zones
AQUATIC ECOLOGY:
Oligitrophic vs Eutrophic systems?
In lakes!
Younger lakes = oligitrophic
Older Lakes = eutrophic (process of nutrient increase) less O2, more algae!
Eutrophication is the process of nutrient enrichment in an aquatic system. The process of anthropogenic eutrophication occurs due to the addition of excessive nutrients to aquatic systems. We are causing an artificial increase in eutrophication.
Consequences : human caused. (look at chart for consequences)
Stratification of Lakes?
Describe importance of Spring/Autumn ‘overturn’ and how it is beneficial for productivity:
Once water is 4 C, it drops to the bottom of the lake. The point at where it goes from warmth to coolness is called the thermocline area (in the middle of the metalimnion)
Freshwater Wetlands.
Freshwater Marshes:
BE AWARE IF IT’S FRESHWATER OR MARINE.
Most people are familiar with the cattail or lily pad wetland found in areas with standing water, but wetlands can also be grassy meadows, shrubby fields, or mature forests. Many wetland areas have only a high ground water table and standing water may not be visible. Types of wetlands include deciduous swamps, wet meadows, emergent marshes, conifer swamps, wet prairies, shrub-scrub swamps, fens, and bogs (Source: VanBuren Michigan website)
estuaries
marshes
intertidal zones
mangrove swamps
Many wetlands are being destroyed due to building our cities. Plowed and built over.
Pros:
* water quality improvement
* habitat for birds, fish, amphibians
* plant diversity
* flood protection/shoreline erosion control
Coral Reefs and their importance:
Corals (Cnidarians) form a mutualism with Zooxanthellae.
How do they benefit: Corals provide protection. Zoo’s give sugars to corals.
Importance of Reefs: High productivity, nursery habitat for 250,000 known species, protection for animals, protection to shores from erosion and provide food sources for people.
AQUATIC ECOLOGY:
Open Oceans and it’s importance:
What is upwelling?
Similar to deserts – lower productivity because lack of nutrients, lack of sunlight.
Neritic at margins of ocean and pelagic is beyond the continental shelf.
Nutrients vary with ‘upwellings’ and light is available in the photic zone.
Why do the poles tend to have very nutrient rich waters? Cold water is denser, it sinks and pushes deeper water up to the top (upwellings) with the nutrients.
“Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity. Therefore, good fishing grounds typically are found where upwelling is common”
aquatic ecology:
Hydrothermal Vents and their important:
Almost all ecosystems rely on solar energy harnessed by photosynthesis. Hydrothermal vents are an exception.
Where does the energy come from, for these ecosystems? These microbes are the foundation for life in hydrothermal vent ecosystems. Instead of using light energy to turn carbon dioxide into sugar like plants do, they harvest chemical energy from the minerals and chemical compounds that spew from the vents—a process known as chemosynthesis . The bacteria are chemosynthetic. They oxidize hydrogen sulfide, add carbon dioxide and oxygen to produce sugar (food), sulfur, and water. The food that chemosynthetic bacteria produce serves as the base of the hydrothermal vent food web. (Smithsonian website)
PHOTOSYNTHESIS : H2O + CO2 –> sugars + O2
CHEMOSYNTHESIS : H2O + CO2 +H2S + O2 –> simple CH2O + H2SO4 (oxidation occurs)
