Effects of Climate on Biomes Study Notes

Climate consists of temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological measurements in a region over long periods.
Climate determines the nature of a biome (dry/wet, hot/cold, humid).

A biome is a group of similar ecosystems sharing the same general abiotic factors and primary producers.
Terrestrial biomes are land areas on Earth inhabited by organisms.
Distinguishing features of terrestrial biomes are mainly determined by climate.
Examples of terrestrial biomes: tundras, temperate forests and grasslands, chaparral, temperate and tropical deserts, and tropical forests and grasslands.

Climate is the average weather in an area over a long period, while weather refers to day-to-day atmospheric conditions.
Climate is generally described by temperature and moisture.
Temperature decreases from the equator to the poles.
Major temperature zones based on latitude: tropical, temperate, and arctic.
Proximity to the ocean can moderate temperatures, leading to cooler summers and warmer winters compared to inland areas.
Temperature decreases with altitude, which is why tropical mountain tops can have snow.
Climates are classified by moisture levels as arid (dry), semi-arid, humid (wet), or semi-humid.
Moisture depends on precipitation (increases moisture) and evaporation (decreases moisture).
The global precipitation pattern is influenced by air mass movements.
Warm air holds more moisture than cold air, leading to higher rainfall in tropical areas.
Proximity to the ocean and mountain ranges influences precipitation.
Evaporation is greatest in hot, sunny conditions.
Cold climates with low precipitation may not be as dry as warm climates with the same precipitation.
Rain Shadow Effect:
- Moist air from the ocean rises over a mountain range.
- As the air rises, it cools, and water vapor condenses.
- Precipitation occurs on the windward side of the mountain range.
- The leeward side receives dry air, resulting in little precipitation and a “rain shadow.”

Plants need air, warmth, sunlight, water, and nutrients.
How well these needs are met depends on the growing season and soil quality, both influenced by climate.
Growing season: the period when it is warm and wet enough for plant growth. This duration varies based on climate.
Soil quality: Plants thrive in soil rich in nutrients and organic matter.
Nutrients and organic matter are added to the soil through decomposition of plant litter and dead organisms.
Decomposition rates:
- Slow in cold climates, hindering accumulation of nutrients.
- Fast in hot, wet climates, preventing accumulation of nutrients.
- Therefore, temperate climates often have the best soil for plant growth.

Climate dictates plant growth, which in turn influences the biodiversity of a terrestrial biome.
Biodiversity generally increases from the poles to the equator and in more humid climates.

Organisms evolve adaptations to survive in their biome's climate.
Examples of adaptations to arid climates:
- Plants with tissues for water storage (e.g., aloe, cactus).
- Animals with adaptations to conserve water (e.g., Gila monster’s fat tail for water storage, kangaroo rat's efficient kidneys that produce concentrated urine).
Examples of adaptations to cold climates:
- Plants becoming dormant and shedding leaves during the coldest periods.
- Animals developing insulation in the form of fur and fat (e.g. polar bears).