Sapere

• Climate:
  • The average weather conditions—temperature, precipitation, humidity, wind—in an area measured over a long period (usually 30 years or more).
• Biome:
  • Large ecological regions characterized by distinctive climate, plant communities, animal populations, and soil types.
  • Examples: tropical rainforest, tundra, desert, grassland, temperate forest.

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☀️ 2. Factors Determining Climate

Climate in any given region is influenced primarily by:

a) Latitude

• Distance from the equator determines sunlight intensity.
• Equator receives direct sunlight, creating warmer climates; poles receive indirect sunlight, resulting in colder climates.

b) Altitude

• Higher altitudes (mountainous regions) experience cooler temperatures and different precipitation patterns compared to sea level.

c) Ocean Currents

• Influence temperature and precipitation on land.
• Warm currents (e.g., Gulf Stream) warm nearby coasts; cold currents (e.g., Humboldt Current) cool adjacent areas.

d) Prevailing Winds

• Distribute heat and moisture, influencing temperature and rainfall.

e) Proximity to Water Bodies

• Coastal areas experience milder climates, whereas continental areas see more extremes.

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🌳 3. Major Terrestrial Biomes

Each biome is characterized by unique climatic conditions and species adapted to them:

Biome	Climate features	Typical Vegetation	Animal Examples
Tropical Rainforest	Hot, humid; abundant rainfall year-round	Broad-leaved evergreens, vines	Jaguars, monkeys, parrots
Savanna (Tropical Grassland)	Warm, seasonal rainfall; distinct wet and dry seasons	Grasses, scattered trees	Zebras, giraffes, lions
Desert	Very low precipitation; hot or cold temperatures	Cacti, succulents, shrubs	Camels, snakes, lizards
Temperate Grassland	Moderate precipitation; hot summers, cold winters	Grasses, herbs	Bison, wolves, rodents
Temperate Deciduous Forest	Four distinct seasons; moderate rainfall	Deciduous trees (oak, maple)	Deer, foxes, birds
Taiga (Boreal Forest)	Cold climate, moderate precipitation; snowy winters	Coniferous trees (spruce, fir)	Bears, moose, wolves
Tundra	Extremely cold; low precipitation; short summers	Mosses, lichens, low shrubs	Polar bears, reindeer, arctic foxes

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🌊 4. Aquatic Biomes

• Marine Biomes:
  • Oceans, coral reefs, estuaries.
  • Influenced by salinity, depth, temperature, and currents.
• Freshwater Biomes:
  • Lakes, rivers, wetlands.
  • Influenced by nutrient levels, flow rate, and oxygen availability.

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🔄 5. Climate–Biome Relationship

• Biomes represent stable states within climatic systems.
• Changes in climate (e.g., global warming) trigger shifts in biome boundaries and ecosystem dynamics.
• Feedback loops: Climate change impacts vegetation → altered carbon storage capacity → further climate impacts.

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⚠️ Human Impacts on Climate and Biomes

• Deforestation & Habitat Destruction
  • Causes loss of biodiversity and disrupts carbon cycles.
• Agriculture & Urbanization
  • Leads to soil degradation, habitat fragmentation, and altered water cycles.
• Climate Change
  • Shifts biome distribution, affecting species migration and survival.
  • Increasing frequency and severity of extreme weather events.

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🌱 Case Studies

1. Amazon Rainforest (Tropical Rainforest Biome)

📍 Location:

• Spanning across Brazil, Peru, Colombia, and several other South American countries.

🌦️ Climate:

• Hot and humid year-round.
• Annual rainfall: 2,000–3,000 mm.
• Average temperature: 26–27°C.

🪴 Biome Features:

• Dense biodiversity: over 16,000 tree species, 2.5 million insect species.
• High biomass and productivity.
• Important carbon sink for regulating global climate.

🚨 Human Impacts:

• Deforestation for cattle ranching, soy farming, and logging.
• Slash-and-burn agriculture releases carbon dioxide into the atmosphere.
• Biodiversity loss due to habitat destruction.
• Disruption of water cycle (less evapotranspiration, reducing rainfall regionally).

🌱 System Implications:

• Positive feedback loop: less forest → less rain → more drought → more fires → further forest loss.
• Global implications: contributes to climate change, impacts indigenous communities.

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2. Sahel Region (Savanna to Desert Transition)

📍 Location:

• Band across Africa south of the Sahara Desert (e.g., Senegal, Mali, Chad, Sudan).

🌦️ Climate:

• Semi-arid with highly variable rainfall.
• Short rainy season, long dry season.

🪴 Biome Features:

• Grassland with scattered trees.
• Home to nomadic herders and farmers.

🚨 Human Impacts:

• Desertification from overgrazing, deforestation, and unsustainable farming.
• Soil degradation and loss of agricultural productivity.
• Food insecurity and mass migrations.

🌱 System Implications:

• Negative feedback loop: land degradation reduces vegetation → less evapotranspiration → less rainfall → further desert spread.
• Vulnerability worsened by climate change (increased droughts).

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3. Great Barrier Reef (Marine Biome)

📍 Location:

• Off the northeast coast of Australia.

🌦️ Climate:

• Tropical marine environment with warm sea temperatures.

🪴 Biome Features:

• Largest coral reef system in the world.
• High biodiversity: over 1,500 fish species, 400 coral species.

🚨 Human Impacts:

• Coral bleaching due to rising sea temperatures.
• Ocean acidification weakens coral skeletons.
• Pollution from agricultural runoff (nutrient loading leading to eutrophication).
• Overfishing disrupts the reef food web.

🌱 System Implications:

• Loss of coral reefs → collapse of reef ecosystems → loss of fish populations → impacts on food security and tourism.
• Feedback loop: dead reefs reduce coastal protection → more shoreline erosion.

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4. Arctic Tundra (Tundra Biome)

📍 Location:

• Northern Canada, Alaska, Russia (Siberia), Greenland.

🌦️ Climate:

• Extremely cold, long winters, short cool summers.
• Low precipitation (~150–250 mm annually).

🪴 Biome Features:

• Low biodiversity: mosses, lichens, small shrubs.
• Permafrost (permanently frozen ground) underlies the soil.

🚨 Human Impacts:

• Climate change causing permafrost thaw.
• Release of methane (CH₄) and carbon dioxide (CO₂), potent greenhouse gases.
• Loss of habitat for cold-adapted species like polar bears and Arctic foxes.

🌱 System Implications:

• Positive feedback loop: permafrost melts → GHGs released → warming increases → more permafrost melts.
• Accelerates global climate change.

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📚 Key Terms

Keyword	Definition
Climate	Average weather conditions over long-term periods.
Biome	Large ecosystems defined by climate, flora, and fauna.
Latitude	Geographical coordinate determining solar radiation received.
Desertification	Process where fertile land becomes desert, often due to drought or unsustainable agriculture.
Feedback loops	Cyclical processes where system outputs influence future inputs, amplifying or stabilizing system changes.