APES Chapter 5 Study Guide

a. Three major types of terrestrial ecosystems:

Grasslands, Forests, Desserts

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b. Each of these (above) simply known as Biomes

c. The role of Climate in determining Biome Type

Climate determines biome types through temperature, precipitation, and seasonal variations, which shape the environment, plant life, and animal species in each region. Warm, wet areas form biomes like tropical rainforests, while cold or dry areas lead to tundras and deserts. Seasonal changes also influence growth and migration patterns, defining the characteristics of different biomes.

d. How Climate is defined (vs. weather)

Climate refers to the long-term patterns of temperature, precipitation, and weather conditions in a region over decades or centuries, while weather describes short-term atmospheric conditions that can change daily.

e. Major factors contributing to regional climate: Convection Cells (Hadley Cells*), Uneven Heating of Earth’s Surfaces, Tilt of Earth’s axis, Earth’s Rotation, (* is sometimes reserved for the two cells nearest Equator), Ocean Currents

Convection Cells (Hadley Cells): Large-scale air circulation patterns that distribute heat from the equator to higher latitudes, with Hadley Cells specifically near the equator.

Uneven Heating of Earth’s Surfaces: Differences in solar energy absorption between the equator and poles drive temperature variations and wind patterns.

Tilt of Earth’s Axis: Earth's tilt causes seasonal changes as different regions receive varying amounts of sunlight throughout the year.

Earth’s Rotation: Influences wind and ocean current patterns through the Coriolis effect, affecting climate zones.

Ocean Currents: Transport warm and cold water around the globe, regulating coastal and regional climates.

f. Latitude, Insolation (Incoming Solar Radiation in a given area), Solar Cycles (we tend to think of the Sun as quite “constant”)

Latitude: Determines how much solar energy an area receives, with equatorial regions getting more direct sunlight and polar regions receiving less.

Insolation (Incoming Solar Radiation): The amount of solar energy reaching a specific area; higher insolation leads to warmer temperatures.

Solar Cycles: Variations in the Sun's activity, like sunspots, can cause slight changes in solar energy output, impacting Earth's climate, even though the Sun is generally seen as stable.

g. Gyres

large systems of circular ocean currents formed by the Earth's rotation and wind patterns. They play a crucial role in regulating regional climates by redistributing heat across the planet's surface. Warm water from the equator is carried to higher latitudes, while cooler water is transported back toward the equator, influencing coastal climates and weather patterns

h. Milankovitch Cycles

Milankovitch Cycles are long-term variations in Earth's orbit and orientation that affect climate over thousands of years. They consist of three main components:

1. Eccentricity: Changes in the shape of Earth's orbit around the Sun, ranging from more circular to more elliptical, affecting how much solar energy the planet receives.

2. Axial Tilt (Obliquity): Variations in the angle of Earth's tilt, which influence the severity of seasons.

3. Precession: The wobble in Earth's rotational axis, which affects the timing of seasons in relation to Earth's position in its orbit.

i. The Core Case Study provides a little focus on savannas (a tropical grassland); savannas would be most associated with EXTREMES in what Climatic factor? Please apply the same question to grasslands that remain / or have been restored in places such as Kansas, Nebraska, Iowa, Illinois, and Missouri (temperate grasslands)

Savannas (tropical grasslands) are most associated with extremes in precipitation, experiencing distinct wet and dry seasons that greatly influence vegetation and animal life.

j. Please be comfortable with the following: Our ancestors near the end of the last Ice Age, about 10,000 years ago (marking the beginning of the Holocene), and the transition from Hunter-Gatherers to farming, given Holocene conditions; which biome type(s) was / is best, typically, for agriculture? Please describe the

characteristics or qualities that allow this.

At the end of the last Ice Age, around 10,000 years ago, our ancestors transitioned from hunter-gatherers to farming, typically favoring temperate grasslands and temperate deciduous forests for agriculture. These biomes are characterized by fertile soil, a moderate climate, and predictable seasonal changes, making them ideal for growing a variety of crops.

k. Warm Fronts and Cold Fronts

Warm fronts occur when warm air replaces cooler air, leading to steady, prolonged rain and gradual temperature increases. In contrast, cold fronts happen when cold air moves in, forcing warm air to rise quickly, resulting in thunderstorms and abrupt temperature drops. Warm fronts create gradual weather changes, while cold fronts cause more sudden shifts.

l. The Jet Stream

The Jet Stream is a fast-moving band of air in the upper atmosphere, typically around 30,000 feet, flowing from west to east. It forms at the boundary between cold polar air and warmer tropical air and comes in two main types: the Polar Jet Stream and the Subtropical Jet Stream. The jet stream significantly influences weather patterns by affecting storm paths, temperature variations, and precipitation, often causing severe weather when it shifts or becomes unstable.

m. El Nino Southern Oscillation (ENSO): ENSO is a warming event [vs. La Nina (increased cooling_ and Increased upwelling_ ]: What happens during an ENSO event? Why is this change to the usual or “normal” pattern noteworthy? Please be comfortable with the following in the context of ENSO: “normal” East to West Trade Winds, Thermocline Dynamics, Potential Ramifications:

The El Niño Southern Oscillation (ENSO) is a climate pattern in the Pacific Ocean that involves periodic warming (El Niño) and cooling (La Niña) of ocean surface temperatures.

### Key Points:

1. El Niño:

   - Characterized by warmer ocean temperatures in the central and eastern Pacific.

   - Disrupts the normal east-to-west trade winds, pushing warm water towards the eastern Pacific and reducing nutrient availability.

2. La Niña:

   - Marked by increased cooling and upwelling of cold, nutrient-rich water.

   - Strengthens the trade winds and enhances normal ocean circulation.

3. Thermocline Dynamics:

   - During El Niño, the thermocline is shallower in the eastern Pacific, reducing marine productivity.

   - La Niña deepens the thermocline, enhancing nutrient upwelling and supporting greater biological activity.

4. Potential Ramifications:

   - Changes in weather patterns, including droughts and heavy rainfall.

   - Significant impacts on agriculture, leading to crop failures or increased yields.

   - Economic effects, particularly in agriculture and fisheries.

### Noteworthiness:

The shifts from "normal" conditions during ENSO events disrupt established climate patterns, leading to significant global climatic and ecological changes, with effects felt worldwide. Understanding ENSO is crucial for predicting climate variability and preparing for its impacts.

n. The Role of Greenhouse Gases in determining Climate

Greenhouse gases (GHGs) are vital for regulating Earth's climate by trapping heat in the atmosphere. While naturally occurring GHGs support a habitable climate, human activities have increased their levels, enhancing the greenhouse effect and contributing to global warming and climate change. This results in extreme weather, altered precipitation patterns, and significant impacts on ecosystems and human life.

o. The Rainshadow Effect:

The Rainshadow Effect occurs when moist air rises over a mountain range, causing precipitation on the windward side and creating a dry area (the rainshadow) on the leeward side. As the air ascends, it cools and loses moisture, resulting in lush vegetation on the windward side and arid conditions on the leeward side. This phenomenon significantly influences local climates, leading to distinct differences in precipitation and ecosystems, as seen in regions like the Pacific Northwest of the United States.

p. Major Characteristics of each Biome:

Please be comfortable with 1, 2, or 3 characteristics for each of the following:

1. Deserts

• Characteristics: Low precipitation (<10 inches/year), high temperature variability, sparse vegetation.

• Ecosystem Services: Carbon storage, habitat for unique species, and potential medicinal resources.

• Human Impacts: Urbanization, overgrazing, and habitat destruction.

2. Tropical Dry Forests

• Characteristics: Distinct wet and dry seasons, deciduous trees, high biodiversity.

• Ecosystem Services: Soil formation, water regulation, and carbon sequestration.

• Human Impacts: Deforestation, agriculture expansion, and land conversion for urban development.

3. Tropical Rain Forests

• Characteristics: High annual rainfall (>80 inches), dense canopy, high biodiversity.

• Ecosystem Services: Biodiversity hotspots, carbon storage, and climate regulation.

• Human Impacts: Deforestation, logging, and land conversion for agriculture.

4. Temperate Deciduous Forests

• Characteristics: Four distinct seasons, deciduous trees, rich soil.

• Ecosystem Services: Timber production, water purification, and habitat for diverse species.

• Human Impacts: Logging, urbanization, and pollution.

5. Evergreen Coniferous Forests (Taiga)

• Characteristics: Dominated by coniferous trees, long cold winters, and acidic soils.

• Ecosystem Services: Carbon storage, timber resources, and wildlife habitat.

• Human Impacts: Logging, mining, and climate change effects.

6. Chaparral

• Characteristics: Hot, dry summers and mild, wet winters; drought-resistant shrubs.

• Ecosystem Services: Soil stabilization, erosion control, and habitat for unique species.

• Human Impacts: Urban development, wildfires, and invasive species.

7. Savanna (Tropical Grassland)

• Characteristics: Warm temperatures, distinct wet and dry seasons, dominated by grasses.

• Ecosystem Services: Biodiversity conservation, carbon storage, and tourism opportunities.

• Human Impacts: Agriculture expansion, poaching, and habitat destruction.

8. Temperate Grassland

• Characteristics: Moderate rainfall, hot summers, cold winters, dominated by grasses.

• Ecosystem Services: Fertile soil for agriculture, habitat for species, and carbon storage.

• Human Impacts: Agriculture, overgrazing, and urban development.

9. Arctic Tundra (Polar Grassland)

• Characteristics: Extremely cold temperatures, permafrost, limited vegetation.

• Ecosystem Services: Carbon storage, habitat for unique species, and water regulation.

• Human Impacts: Climate change, oil extraction, and habitat disruption.

10. High Mountains

• Characteristics: Variable climate with elevation changes, ecosystems change rapidly.

• Ecosystem Services: Water source for downstream ecosystems, biodiversity hotspot.

• Human Impacts: Mining, tourism, and climate change.

11. Polar Ice

• Characteristics: Ice sheets and glaciers, extremely cold temperatures, limited vegetation.

• Ecosystem Services: Climate regulation, habitat for polar species, and global temperature regulation.

Human Impacts: Climate change, melting ice due to global warming, and pollution.