1. BIOMES AND AQUATIC ECOSYSTEMS

3. A. Biomes Major types of terrestrial ecosystems. Distribution of biomes largely depends on climate (temperature & rainfall). Climate is determined by the Earth’s tilt & uneven heating of Earth’s surface. Tilt produces seasons in northern & southern hemispheres.

4. Earth’s tilt produces…?

5. Unequal heating causes air movements that distribute moisture. Altitude influences climate - conditions usually become drier & colder as altitude increases.

6. Air circulation & biomes Note the closed air cells? Wind patterns distribute suns heat=?? Ocean currents too related to weather??

7. Elevation & biomes

8. Rain shadow effect

9. Earth’s major biomes

11. 1. Tropical Rain Forest warm & moist (rainfall: 79-157 in/yr) nutrients cycle rapidly soils are nutrient poor plants exhibit vertical stratification very high biodiversity

12. Tropical Rain Forest Avg high temp High avg rainfall Adaptations?

13. 2. Tropical Dry Forest wet & dry seasons temperature fluctuates soils are rich in nutrients organisms adapted to seasons

14. Tropical desert Avg high temp Little rainfall Adaptations??

15. 3. Tropical Savanna wet & dry seasons (rainfall: 12-20 in/yr) mainly grasslands; few scattered trees & shrubs organisms adapted to wet/dry seasons (migrating herbivores) frequent fires maintain grassland

16. 4. Desert dry (rainfall: < 8 in/yr) hot days / cool nights plants adapted to obtain & store water rapid life cycles deep roots (mesquite) succulent tissues / reduced leaves (cacti)

17. Temperate desert High avg temp Low rainfall Adaptations?

18. animals adapted to minimize water loss tough, waterproof integument concentrated urine nocturnal habits Atriplex (saltbush plant) stores salt in outer cells of leaves. Red vizcacha rat has adaptation that allows it to feed on Atriplex.

19. 5. Temperate Grasslands (prairie) 1 or 2 dry seasons/year (rainfall: 10-40 in/yr) lack trees & shrubs grazing & frequent fires maintain grass In US, majority of prairie has been replaced by farmland.

20. Temperate grassland Freezing ‘vernalizes’ seeds Very productive

21. Grassland Dry season Rainy season Avg high temp

22. 6. Temperate Forests rainfall: 26-118 in/yr Temperate forests are either deciduous or coniferous. Temperate Deciduous Forest oak-hickory or beech-maple predominate moist growing season (at least 4 months) soil rich in nutrients vertical stratification organisms adapted to seasonal changes

23. Temperate deciduous forest Leaves lost in winter…why?

24. Temperate Coniferous Forest spruce, pines, firs & hemlocks predominate summers typically dry; long, harsh winters soil is thin, acidic & poor in nutrients understory of shrubs adapted to recurring fires

25. 7. Taiga (boreal forest) precipitation falls as snow/ice (8-24 in/yr) long, cold winters soil is thin, moist, acidic & nutrient poor (subsoil may be frozen) biodiversity lower than temperate zone conifers predominate

26. Taiga Average low temp Avg. low rainfall I.e. ‘frozen desert’

27. 8. Tundra Precipitation: 8- 24 in/yr long, bitterly cold winters permafrost begins 18 in. below surface low biodiversity shallow-rooted shrubs & lichens plants adapted to short growing season animals adapted to cold (small extremities) & snow (many are camouflaged)

28. Tundra Low avg temp Low rainfall Adaptations?

29. Polar Desert Note avg higher temp than tundra

30. Aquatic Ecosystems Freshwater Ecosystems Lakes and Ponds (standing water) littoral zone limnetic zone profundal zone benthic zone

31. Oxygen & nutrients (nitrogen/phosphorus) are unevenly distributed in lakes. O 2 level is highest near surface nutrient level is highest near bottom Oxygen & nutrients are redistributed by: wind (ponds & shallow lakes) fall & spring turnover (deep lakes in temperate regions)

32. Oligotrophic lakes young; low in nutrients & productivity clear & sparkling blue deep water is oxygen-rich Eutrophic lakes older; nutrient rich & high in productivity green & murky O 2 often depleted in deep water during summer Nutrients in sewage & agricultural runoff speed eutrophication.

33. Rivers and Streams (running water) Transport rainwater, groundwater, snowmelt & sediment from land to ocean or lake. At headwaters: channel is narrow water is clear & oxygen-rich current is swift At mouth: channel widens water is murky & contains less oxygen current slows, depositing sediment

34. 2. Marine Ecosystems Coastal Ecosystems Include estuaries, mangrove swamps, the intertidal zone & coral reefs. Estuary - area where fresh water of river meets salty water of ocean. water is brackish salinity fluctuates very productive high biodiversity nursery for many ocean animals

35. Ocean currents & biomes

36. Mangrove Swamp - tropical wetland dominated by salt- tolerant plants (mangroves). transitional zone between forest & ocean salinity fluctuates plants have aerial roots high biodiversity

37. Intertidal Zone - area along coast between high & low tides. organisms adapted to pounding waves & varying degrees of desiccation low productivity Coral Reef - underwater deposits of calcium carbonate formed by colonies of animals. very productive high biodiversity very fragile

38. Ocean Ecosystem covers 71% of Earth’s surface temperature: 35 o F - 81 o F sunlight quickly dissipates with depth primary producers are photoautotrophs (found near surface) & chemoautotrophs (found at deep-sea hydrothermal vents) highest productivity near upwellings (occurs on western side of continents)

40. And, what did we learn? What is a biome? List 2 major factors that determine? List 7 major biomes & climates Compare freshwater ecosystems Lakes vs flowing sources Marine ecosystems (coastal & open)

41. What is an ECOSYSTEM? Total interactions of living and nonliving things in a defined area. Composed of ENERGY and NUTRIENT inputs/outputs

42. Energy flow in an ecosystem One-way flow… High ‘quality’ to… Low ‘quality’ is… Entropy Energy is NOT recycled!

43. Nutrient recycling (i.e. Carbon)

44. Food chains

45. Decomposers…important?

46. A food/energy pyramid What happens at each level? Why are there fewer consumers than producers? Why are decomosers at all levels?

47. Food/Energy WEBS Series of food chains Interlaced More stable than food chain…why? GRAZING… DETRITAL…

48. Primary productivity Biomass pyramids?? Energy pyramid Kilocal/M 2 /year

49. Relative Biome productivity

50. El nino…Southern oscillation

57. Population diversity vs space