Chapter 7: Climate and Terrestrial Biodiversity
What Factors Influence Climate?
The Earth Has Many Different Climates
- Weather: Local area’s short-term temperature, precipitation, humidity, windspeed cloud cover, and other conditions.
- Climate: Area’s general pattern of the atmosphere over a long period of time.
- Ocean Currents: Prevailing winds and earth rotation.
- Tropical: Equator, intense sunlight
- Polar: Poles, little sunlight
- Temperate: In-between tropical and polar
El Nino- Southern Oscillation
- El Niño-Southern Oscillation: It happens every few years. Prevailing winds in the tropical Pacific Ocean change direction. It affects much of earth’s weather for 1-2 years
Greenhouse Gases Warm the Lower Atmosphere
- Greenhouse gases: H20, CO2, CH4, N2O
- Greenhouse effect: Gases keep the earth warm and habitable
- Moist air rises cool and releases moisture as rain
Earth’s Surface Features Affect Local Climates
- Rain Shadow Effect: Most precipitation falls on the windward side of mountain ranges.
How Does Climate Affect the Nature and Locations of Biomes?
Climate Helps Determine Where Organisms Can Live
- Major biomes: Large land regions with certain types of climate and dominant plant life
- Abiotic factors * Latitude * Elevation * Precipitation * Temperature
There Are Three Major Types of Deserts
- Tropical deserts: Hot and dry most of the year. They have few plants and are often deserts that are seen in movies.
- Temperate deserts: Temperatures are high in the summer and low in winter and they have more precipitation.
- Cold deserts: Winters are cold and summers are hot. Precipitation is also low.
- They have fragile ecosystems * Slow plant growth * Not a lot of species diversity * Lack of water
There Are Three Major Types of Grasslands
- Grasslands: This happens in areas that are too moist for deserts and too dry for forests.
- Tropical * Savanna: Brazing and browsing animals
- Temperate: Cold winters and hot and dry summers, with tall and short grass prairies * Chaparral:
- Artic tundra: Fragile biome with plants close to the ground. They also have short summers and the animals there have thick fur * Permafrost: Underground soil that stays frozen
- Alpine Tundra: Above the tree line in the mountains
How Have We Affected the World’s Terrestrial Ecosystem?
Major Human Impacts on Terrestrial Ecosystem
- Deserts * Large desert cities * Soil destruction by off-road vehicles * Soil salinization from irrigation * Depletion of groundwater * Land disturbance and pollution from mineral extraction
- Grasslands * Conversion to cropland * Release of CO2 to the atmosphere from burning grassland * Overgrazing by livestock * Oil production and off-road vehicles in the arctic tundra
- Forest * Clearing for agriculture, livestock grazing, timber, and urban development * Conversion of diverse forests to tree plantations * Damage from off-road vehicles * Pollution of forest streams
- Mountains * Agriculture * Timber extraction * Mineral extraction * Hydroelectric dams and reservoirs * Increasing tourism * Urban air pollution * Increased ultraviolet radiation from ozone depletion * Soil damage from off-road vehicles
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