Unit III Nutrients & Biomes

1. Unit IIINutrients & Biomes

2. Nutrient Cycles • Carbon Cycle • Based on CO2 cycling from animals to plants during respiration and photosynthesis. • Heavy deposits are stored in wetland soils, oceans, sedimentary rocks. • under right conditions, can become fossil fuels • Released by combustion and volcanic activity. • Returns to the soil from the atmosphere through rainfall • Carbonic Acid + H20 = Rain with a pH of ~5.4

4. Nutrient Cycles • Nitrogen Cycle • Nitrogen Fixation • Bacteria converts gaseous nitrogen to ammonia • ex: Rhizobium conversion of N to ammonium ions. • Nitrification • Plants absorb ammonium ions as a nutrient. • Passed on to animals. • Used to make vital organic compounds • CHON

6. Nutrient Cycles • Phosphorous Cycle • Based on phosphate ions (PO43-) usually found in rock formations and ocean sediments. • Released by weathering and volcanic activity. • Plants uptake nutrients and pass them on to animals. • Waste products, animal remains, and runoff return phosphate.

8. Nutrient Cycles • Sulfur Cycle • Most sulfur found in rocks, minerals, and ocean sediments. • Sulfur enters atmosphere through weathering, sea spray, and volcanic activity (H2S, SO2). • Returns to the earth from the atmosphere in the form of acid rain. • Avg. pH is 4.3

10. Nutrient Cycles • Hydrologic Cycle (aka) Water Cycle • Evaporation and Transpiration • Condensation and Precipitation • Infiltration and Percolation • Runoff

12. Atmosphere • Troposphere • inner layer of the atmosphere • physical properties include: • temperature • precipitation • cloud cover • wind direction and speed • these properties (and others) at a given time and place are called the weather. • Stratosphere • second layer of the atmosphere

13. Winds • Global air circulation patterns are affected by: • uneven heating of the earth’s surface. • seasonal changes. • earth’s rotation. • long-term variations in the amount of solar energy striking the earth. • properties of air and water.

14. What is the Earth’s tilt? • 23.5º

15. Winds • Warm Fronts • leading edge of a mass of warm air converging on a mass of cool air • less dense, warm air rises above the cool air • moisture condenses and produces clouds • often the clouds will descend and produce precipitation

16. Winds • Cold Fronts • leading edge of a mass of cool air converging on a mass of warm air • denser cool air stays toward the ground • produces rapidly moving towering clouds called thunderheads • cold fronts bring high surface winds and thunderstorms but then cooler, clear skies afterward

17. Pressure • Highs • high pressure air masses that descend towards the earth’s surface • produces fair weather • Lows • low pressure air masses that rises • rising cools and expands the air causing precipitation High Low High Low High Low High

19. Ocean Currents • Created by same reasons as winds. • Distributes heat, nutrients, and DO. • Upwellings • occurs from constant trade winds • They push surface water out which is replaced by cool, deep water rich in nutrients.

21. El Nino – Southern Oscillation (ENSO) • Trade winds normally blow warm water off the coast of South America and California (creates upwellings). • When winds fail, weaken, or change direction, the waters warm and stagnate. • Causes less productivity and possibly red tide. • As the Pacific surface temperature becomes warmer, global weather patterns are disrupted • First seen with wetter weather in eastern Pacific.

23. La Nina • Opposite of El Nino. • Trade winds will increase in strength • Weather patterns are also affected • Opposite effects of El Nino

24. Climate and Weather • Climate • average long term weather • ~30 years of data • basically determined by average temperature and average precipitation • Winds • create climate • circulate heat, moisture, and nutrients. • also transport bacteria, viruses, pollution and radioactive wastes.

25. Rain Shadow Effect • AKA: Orographic Uplift • warm air rises and releases moisture on windward side of mountain. • air on leeward side is cooler and dry. • creates a distinctive microclimate on either side of mountain.

27. Microclimate Factors • Vegetation • affects humidity, winds, and creates shadows. • warmer in winter, cooler in summer. • Cities • buildings, asphalt, and vehicles raise temperatures and create haze and smog.

28. Plate Boundaries • Convergent • Transform • Divergent

29. Biomes • Biome • A large, relatively distinct terrestrial region with a similar climate soil, plants, and animals, regardless of where it occurs in the world • Typically determined by: • Climate • especially precipitation • Latitude • distance from the equator • Altitude • elevation above sea level

32. Tundras • 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

33. Tundras • Nutrient poor soils with little organic material • Permafrost present • Low species richness • Vegetation is mostly grasses & shrubs • Small herbivores • Occasional Arctic fox & wolf • Low primary productivity

34. Boreal Forests • A region of coniferous forests in the northern hemisphere • Just south of tundra • Growing Season • A little longer than tundra • Precipitation • ~ 50 cm/yr

35. Boreal Forests • Soils are acidic and mineral poor • Vegetation comprised of drought resistant conifers • Mostly small animals • Some large animals • wolves, bear, moose • Aka: • coniferous forest • evergreen forest • taiga

36. Temperate Rainforests • 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

37. Temperate Rainforests • 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

38. Temperate 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

39. Temperate Deciduous Forests • 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

40. Grasslands • Grasslands with hot summers, cold winters and too little precipitation to support trees • Precipitation • 25–75 cm/yr • 90% of this biome has been lost to farmland

41. Grasslands • Soil has thick, organic material rich organic horizon • Periodic fires keep the dominant vegetation • Animals • Once covered with bison • no longer true • Smaller animals are still present (ex: prairie dogs)

42. Grasslands • North America • prairies • South America • pampas • Europe/Asia • steppes • Africa • veld

43. Chaparrals • Also called a Mediterranean Climate • Ex: Southern California • Ex: Greece • Temperature • Mild, moist winters • Hot, dry summers • Frequent fires • Crown vs. Surface

44. Chaparrals • Soil is thin and often not fertile • Vegetation • Dense growth of evergreen shrubs • Lush during the growing season • Animals • Mule deer, chipmunks, many species of birds

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

46. Deserts • Soils low in nutrients and high in salts • Sparse vegetation • cactus and sagebrush • Animals are very small to regulate temperature

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

48. Savannas • Soil low in nutrients due to leaching • Vegetation • Wide expanses of grass, occasional Acacia trees • Animals • Herds of hoofed animals • Large predators - lions, hyenas, etc.

49. Tropical Rainforests • 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

50. Tropical Rainforests • Ancient, weathered, nutrient-poor soil • Nutrients tied up in vegetation, not soil • Vegetation • distinct layers • Canopy • Understory • Forest floor • Animals • Most abundant insect, reptiles and amphibians on earth