Chapter # 6 Major Ecosystems/Biomes of the World

1. Chapter #6Major Ecosystems/Biomes of the World

2. Earth’s Major Biomes • Biome • A large, relatively distinct terrestrial region with a similar climate soil, plants, and animals, regardless of where it occurs in the world • Nine major biomes • Location of each biome is primarily determined by: • Temperature (varies with both latitude and elevation) • Precipitation • Biomes can also be defined by • Winds, rapid temperature changes, fires, floods, etc.

6. What is the Taiga Biome? The taiga is located in Canada, Northern Europe, and Asia. The taiga is full of mainly coniferous forests. The taiga is very cold in the winter and warm in the summer. It contains trees such as the black spruce, and animals such as the snowshoe hare.

7. Abiotic factors of the taiga. The taiga gets between 12 and 33 inches of precipitation each year. The temperatures vary from -58 degrees to 86 degrees Fahrenheit. Because the plants are mostly evergreen, the growing season lasts all year.

8. Plants of the taiga. Balsam Fir- the balsam fir (or Canadian Balsam) is native to Eastern Canada and the Northwestern United States. Black Spruce- native to North America, Newfoundland, and Alaska (also called Swamp Spruce.) Douglas Fir- can get 15-25 ft. wide and 40-60 ft. tall. One of the most important lumber trees

9. Tundra • Treeless biome in the far north with harsh, cold winters and extremely short summers • Precipitation • 10-25 cm/yr • Temperature • Short growing season • 50-160 days

10. Tundra • Nutrient poor soils with little organic material • Permafrost present • Low species richness • Veg is mostly grasses and sedges • Very simple food web • Low primary productivity

11. Rainforest • Coniferous biome with cool weather, dense fog and high precipitation • Ex: Northwest US • Precipitation • > 127 cm/yr • Heaviest in winter • Temperature • Winters are mild • Summers are cool

12. Rainforest • Soils are nutrient-poor, but high in organic material (dropped needles) • Cool temperatures slow decomposition • Dominant Vegetation • Large evergreen trees • Old-growth forest • Variety of cool climate animal life • Very high species richness • Heavily logged

13. Temperature Deciduous Forests • Forest biome that occurs in temperate areas with a moderate amount of precipitation • Precipitation • 75-150 cm/yr • Temperature • Seasonality • Hot summers and cold winters

15. Temperate Deciduous Forest • Topsoil is rich in organic material and underlain by clay • Vegetation is primarily deciduous • Oak, maple, beech • Animals • Deer, bear and small animals • Most of this biome land area has been regenerated after farming & timber harvest

16. Deserts • Biome where lack of precipitation limits plant growth • Temperature • Can very greatly in 24-hr period, as well as yearly (based on location) • Precipitation • < 25 cm/yr

17. Deserts • Soils low in nutrients, high in salts • Vegetation sparse • cactus and sagebrush • Animals are very small to regulate temperature Sonoran Desert

18. Tropical Savanna • Tropical grassland with widely scattered trees • Temperature • Varies little throughout the year • Precipitation • Seasons regulated by precipitation, not temperature • 76-150 cm/yr

19. Savanna • Soil low in nutrients due to leaching • Vegetation • Wide expanses of grass • Occasional Acacia trees • Have fire adaptive characteristics • Animals • Herds of hoofed animals • Large predators- lions, hyenas, etc.

20. Tropical Rainforest • Lush, species-rich biome that occurs where climate is warm and moist throughout the year • Precipitation • 200-450 cm/yr • Very productive biome • Most species-rich biome

21. Tropical Rainforest • Ancient, weathered, nutrient-poor soil • Nutrients tied up in vegetation, not soil • Vegetation • 3 distinct canopy layers • Animals • Most abundant insect, reptiles and amphibians on earth

22. Aquatic Ecosystem • Fundamental Division • Freshwater • Saltwater • Aquatic Ecosystems also affected by • Dissolved oxygen level, light penetration, pH, presence/absence of currents • Three main ecological categories of organisms • Plankton- free floating • Nekton- strong swimming • Benthos- bottom dwelling

23. Freshwater Ecosystems • Includes: • Rivers and streams • Lakes and ponds • Marshes and swamps • Represent 2% of earth’s surface • Assist in recycling water back to the oceans (Biogeochemical Cycling)

24. Rivers and Streams • Changes greatly from headwater to mouth • Headwaters • Shallow, cool, swiftly flowing, high oxygenated • Mouth • Not as cool, slower flowing, less oxygen in water

25. Human Impacts on the Ocean

26. Temperate grasslands prairies, steppes, pampas, veldt…..

27. Temperate grasslands • Prairies and steppes have continental climates characterised by large annual range of temperature, cool - cold winters, with most of precipitation as snow, and hot, commonly droughty summers because of high evapotranspiration rates.

28. North American grasslands Calgary Chicago Cheyenne Omaha Abilene