1. Biomes

2. The axis of rotation is angled 23.5 0 – the latitude that receives the most direct sunlight plus the most hours of sunlight changes throughout the year as Earth orbits the Sun Spring Equinox Spring Equinox (March) – Sun directly overhead – all regions get 12 hours of light + 12 hours of dark – spring begins in Northern Hemisphere; fall in Southern Hemisphere Summer Solstice Summer Solstice (June) – max tilt of Northern Hemisphere toward Sun – longest amount of daylight – summer begins Fall Equinox Fall Equinox (Sept) – opposite of March – day & night equal Winter Solstice Winter Solstice (Dec) – max tilt of Northern Hemisphere away from Sun – shortest daylight – winter begins

4. Biome – an area characterized by typical plants and animals adapted to the yearly temperature and precipitation Each biome contains many ecosystems whose communities are adapted to local variation in climate, soil, and other environmental factors

7. Evaporation > precipitation 30% of Earth Variations in annual temp (red) and precip (blue) tropicaltemperate in tropical, temperate, and cold deserts

8. Tropical Tropical warm temps high humidity photosynthesis year-round Temperate Temperate Deciduous forests: Deciduous forests: seasonal changes broad leaves dropped for cold winters Rain forests Rain forests: evergreens in cool, moist environment Polar Polar Taiga Taiga long, cold winters evergreens adapted to year-round photosynthesis

9. Tropical Tropicalsavanna Temperate Temperateprairie Polar Polartundra

10. Freshwater systems – low levels of dissolved salts Streams and rivers: from mountains to oceans Flow creates different conditions and habitats Headwaters Headwaters: cold, clear, rapidly moving water with high levels of O2 Downstream: slower moving, less O2, warmer temps, more algae and cyanobacteria

11. Standing water: lakes and ponds Life found in layers – temperature, sunlight, dissolved O2, and nutrient availability changes with depth Littoral zone Littoral zone: shallow area around shore; rooted vegetation Limnetic zone Limnetic zone: open offshore area; too deep for rooted plants; food chain begins with phytoplankton Profundal zone Profundal zone: deep water without light; food chain depends on organisms above Benthic zone Benthic zone: muddy bottom; nourished by decaying organic matter

13. Wetlands – land is submerged part or all of the year but is shallow enough for rooted vegetation throughout Swamps Swamps: contain trees Marshes Marshes: mainly nonwoody vegetation (cattails)

14. Estuaries Estuaries Saltmarshes where rives flow into the ocean Nutrient rich areas due to river flow Mangrove swamps Mangrove swamps Also produce nutrient rich mud

15. Intertidal zone Intertidal zone Narrow strip between high and low tide mark on the coastline Difficult habitat for life

16. Coral reefs Coral reefs Warm, shallow water beyond the shoreline

17. The open ocean The open ocean Sunlight cannot penetrate to the bottom Photic zone Photic zone: enough light for photosynthesis Aphotic zone Aphotic zone: lacks light and therefore photosynthesis