Climate Terrestrial Biodiversity Ch 7 What is Climate

Climate & Terrestrial Biodiversity Ch. 7

What is Climate? ◊ Weather - short term; today ◊ Climate - general atmospheric or weather conditions over time Climate is what we expect; weather is what we get.

Climate varies over the surface of the earth ◊ 2 main factors: • Wind - air circulation • Ocean currents ◊ Move warm & cold moisture from one place to another, but unevenly

Focus on AIR ◊ Air circulates warmth & moisture from the tropics to other places

Focus on AIR 3 forces responsible: 1. Tilt of the earth - Earth is heated unevenly

Focus on AIR 3 forces responsible 2. Rotation of the Earth on its axis ◊ equator spins faster than poles ◊ Warm air rising over equator goes N or S then deflected E or W ◊ creates “prevailing winds” - major surface winds that blow almost continuously

https: //www. youtube. com/watch ? v=rcqu. RMa. VSKU https: //www. youtube. com/watch? v=rcqu. RMa. VSKU

Focus on AIR 3 forces responsible 3. The water cycle ◊ heat from the sun evaporates ocean water and transfers it to air ◊ this creates convection cells that circulate heat, air, and moisture

Focus on OCEAN CURRENTS ◊ Prevailing winds blow over ocean & move surface water --> currents

Focus on OCEAN CURRENTS ◊ Currents move warm water to other places • Changes vegetation & climate of the area, especially near the coastline

Focus on OCEAN CURRENTS ◊ Continents and wind currents shape path of ocean currents

Focus on OCEAN CURRENTS ◊ Currents go clockwise in Northern Hemisphere ◊ Currents go counterclockwise in Southern Hemisphere

Focus on OCEAN CURRENTS ◊ Also vertical mixing of water • Cold water sinks - more dense, saltier • Warm water rises - less dense, less salty

OCEAN CURRENTS + AIR CURRENTS 4 EVER ◊ Ocean currents affected by wind ◊ Heat from ocean affects air circulation patterns

For Example ◊ El Niño Southern Oscillation (ENSO) ◊ Changes global weather over 2/3 of the planet due to a relatively small change in wind speed

So… ◊ Air circulation + winds + ocean currents + continents in the way = 6 giant convection cells that shape climate ◊ (3 in north, 3 in south) ◊ Warm wet air rises ◊ Cool dry air sinks

The Atmosphere ◊ Greenhouse gases warm the Earth • H 2 O, CO 2, CH 4, N 2 O

How they work ◊ Light from sun passes through atmosphere ◊ Surface absorbs heat ◊ Heat radiates back up ◊ Some escapes to space ◊ Some absorbed by greenhouse gases - its good! : )

Climate Change ◊ LOTS and LOTS of evidence supports the hypothesis that humans are contributing excess greenhouse gases to the atmosphere - altering earth’s climate ◊ 90 -99% sure of this ◊ Why not 100% ◊ Precautionary Principle (global warming)

Earth’s Surface Features also affect climate ◊ Rain shadow effect • Windward side wet • Leeward side dry

All of this creates BIOMES High Mountains Polar Ice Arctic Tundra Temperate Grassland Tropical grassland (savanna) Chaparral Temperate Coniferous forest Temperate deciduous forest Tropical rainforest Tropical dry forest Tropical Desert Temperate rain forest Temperate desert Cold desert Taiga Tropical and subtropical coniferous forest Pond Inland wetlands (swamps, marshes, prarie potholes) Mangrove forest Riparian (rivers and surrounding area)

All of this creates BIOMES High Mountains Polar Ice Arctic Tundra Temperate Grassland Tropical grassland (savanna) Chaparral Temperate Coniferous forest Temperate deciduous forest Tropical rainforest Tropical dry forest Tropical Desert Temperate rain forest Temperate desert Cold desert Taiga Tropical and subtropical coniferous forest Pond Littoral, intertidal zone Mangrove forest Kelp forest Coral reef Neritic zone (coastal waters) Continental shelf Pelagic zone (open sea) Benthic zone (bottom of lakes and oceans) Hydrothermal vents Cold seeps Estuaries Riparian (rivers and surrounding area) Inland wetlands (swamps, marshes, prarie potholes)

Climate Helps Determine Where Organisms Can Live ◊ Major biomes • Large land regions with certain types of climate and dominant plant life ◊Not uniform ◊Mosaic of patches ◊ Change with latitude and elevation

Climate Helps Determine Where Organisms Can Live (cont’d. ) Hot Wet Dry

3 types of Desert, Grasslands & Forests …know these! ◊ Tropical ◊ Temperate ◊ Cold • Desert – annual precipitation low and often scattered through the year • Grasslands occur in: • Interior continents too moist for deserts and too dry forests • Forests – lands dominated by trees

Humans Have Disturbed Much of the Earth’s Land ◊ About 60% of the world’s major terrestrial ecosystems are being degraded ◊ The human ecological footprint is spreading across the globe

Size and Locations of Biomes Can Change ◊ Biomes are not fixed • They change as the climate changes ◊ Human activities are likely to affect biome placement in the future

Three Big Ideas ◊ Differences in climate: • Based on long-term differences in average temperature and precipitation • Largely determine the types and locations of the earth’s deserts, grasslands, and forests ◊ The earth’s terrestrial systems provide important ecological and economic services ◊ Human activities are degrading and disrupting many of the ecological and economic services provided by the earth’s terrestrial ecosystems

Tying It All Together: A Temperate Deciduous Forest and Sustainability ◊ Climate plays a key role in determining the nature of terrestrial ecosystems ◊ The earth’s dynamic climate system helps distribute heat from solar energy and recycle the earth’s nutrients ◊ In nature, everything is connected