GEOG 101 Spring 2014 Lecture 2

1. GEOG 101 Spring 2014 Lecture 2 Energy Flows, Ecosystems and Global Cycles

2. Learning Outcomes: At the end of this lecture, you should be able to: • Differentiate among the different sources of energy important for Earth’s processes • Describe photosynthesis and respiration, and explain their importance to living things • Define ecosystems and evaluate how living and nonliving entities interact in ecosystem-level ecology • Compare and contrast how water, carbon, nitrogen, and phosphorus cycle through the environment

3. Why is Earth Habitable? 1. Distance from the sun

4. Why is Earth Habitable? 1. Distance from the sun 2. Oxygen rich atmosphere O2 and O3 shield life from harmful UV raditation

5. Why is Earth Habitable? 1. Distance from the sun 2. Oxygen rich atmosphere 3. Abundant water

6. Why is Earth Habitable? • Results in: • Moderate radiation intensities • Surface temperature ~15oC • All three states of water • vapour • liquid • ice

7. Water’s properties for life • Hydrogen bond causes oxygen from one water molecule to be attracted to the hydrogen atoms of another • Water’s strong cohesion allows nutrients and waste to be transported • Water absorbs heat with only small changes in its temperature, which stabilizes systems

8. Water’s properties for life • Less dense ice floats on liquid water • Water dissolves other molecules FIGURE 2.5 (a)

9. Earth’s Main Energy Source: The Sun Solar energy is responsible for: 1) basic life processes: plant growth and reproduction 2) life-support processes: precipitation and soil formation 3) life-threatening processes: hurricanes and tornadoes Available solar energy

10. Earth’s Main Energy Source: The Sun Global distribution of solar radiation

11. Earth’s Main Energy Source: The Sun Global distribution of moisture

12. Major Energy Systems of Earth Solar energy is converted to: 1) heat 2) organic (chemical) compounds Heat energy accounts for 99% of the solar energy and drives: 1) Hydrologic system: cycling of water between Earth’s reservoirs (atmosphere, ocean, lakes etc.) 2) Geochemical (nutrient) system: cycling of chemicals through water, soil, and air 3) Atmospheric circulation: pressure differences due to differential heating create wind 4) Ocean circulation: ocean mixing and currents

13. The sun’s energy powers life • The sun releases electromagnetic radiation, which is a spectrum of energy • Some is visible light • Solar energy drives weather and climate, and powers plant growth

14. The sun’s energy powers life • Photosynthesis = turning light energy from the sun into chemical energy 6CO2 + 6H20 + the sun’s energy  C6H12O6 + 6O2 • Respiration C6H12O6 + 6O2 6CO2 + 6H20 + energy (sugar) (sugar)

15. Earth’s other energy source: Geothermal Energy FIGURE 2.16. Rabbitkettle Hot Springs, Nahanni National Park Reserve

16. Geothermal energy powers Earth’s systems • Hydrothermal vents = host entire communities that thrive in high temperature and pressure on the ocean floor • Chemosynthesis = uses chemical bond energy to produce sugar FIGURE 2.17 6CO2 + 6H20 + 3H2S C6H12O6 + 3H2SO4 (sugar)

17. Systems are networks of relationships • System = a network of relationships among parts, elements or components that interact with and influence one another • Exchange of energy, matter, or information • Open systems receives inputs of energy and , matter produces outputs of both • Closed systems receive input and produce outputs of energy but not matter • Systems can be challenging to understand and predict

18. Feedback loops are common in systems. • Feedback loop = a system’s output serves as input to that same system • Negative feedback loop = act to reduce an initial change and stabilize a system. 3-18

19. Feedback loops are common in systems. • Feedback loop = a system’s output serves as input to that same system • Positive feedback loop = instead of stabilizing a system, it drives it further toward one extreme or another 3-19

20. Systems show several defining properties • Homeostasis = a system maintains constant or stable internal conditions • Resistance refers to the strength of the system’s tendency to remain constant • Resilience is a measure of how readily the system will return to its original state once it has been disturbed • Emergent properties = system characteristics not evident in the components alone • “The whole is more than the sum of the parts” FIGURE 5.2

21. Complex systems: watershed • Environmental entities are complex systems that interact with each other • To solve environmental problems, all appropriate systems must be considered

22. Environmental systems may be perceived in various ways • Categorizing environmental systems helps make Earth’s great complexity comprehensible • For example, the earth consists of structural spheres • Lithosphere = rock and sediment • Atmosphere = the air • Hydrosphere = liquid, solid or vapor water • Biosphere = all the planet’s living organisms and the abiotic portions of the environment • Boundaries overlap, so the systems interact

23. Ecosystems • Ecosystem = all organisms and nonliving entities that occur and interact in a particular area at the same time • Includes abiotic and biotic components • Energy flows and matter cycles among these components • Biological entities are highly intertwined with chemical and physical entities • Interactions and feedback loops Why are healthy ecosystems important?

25. Ecosystems are systems of interacting living and nonliving entities FIGURE 5.8 Energy entering the system is processed and transformed Matter is recycled within ecosystem, resulting in outputs such as heat, water flow, and waste products

26. Energy is converted to biomass • Primary production = conversion ofsolar energy to chemical energy by autotrophs • Gross primary production (GPP) = assimilation of energy by autotrophs • Net primary production(NPP) = energy remaining after respiration. Is used to generate biomass • Available for heterotrophs • Secondary production = biomass generated by heterotrophs • Productivity = rate at which ecosystems generate biomass

27. Net primary productivity High net primary productivity = ecosystems whose plants rapidly convert solar energy to biomass FIGURE 5.9

28. Net primary productivity • Productivity and Climatic conditions • Three broad categories of climatic limitations: • 1) no limitations • 2) seasonal limitations • 3) permanent limitations

29. Net primary productivity • Productivity and Climatic conditions • Three broad categories of climatic limitations: • 1) no limitations • 2) seasonal limitations • 3) permanent limitations no major limitations

30. Net primary productivity Terrestrial Productivity Rates:

31. Net primary productivity Terrestrial Productivity Rates: Wet tropics 2200 gC/m2

32. Net primary productivity Terrestrial Productivity Rates: Midlatitudes (seasonal light and heat) 600-1200 gC/m2 Savanna & Mediterranean (dry season) 600-1200 gC/m2

33. Net primary productivity Terrestrial Productivity Rates: Arctic/Polar (permanent limitations) 5-90 gC/m2 Arid (permanent limitations) 5-90 gC/m2 High Mountains (permanent limitations) 5-90 gC/m2

34. Net primary productivity Ocean Productivity Rates:

35. Net primary productivity Ocean Productivity Rates: Coastal Waters 6000 gC/m2 Deep Ocean <250 gC/m2

36. Nutrients can limit productivity FIGURE 5.10 Dramatic growth of algae in water treated with phosphate • Nutrients = elements and compounds required for survival that are consumed by organisms • Macronutrients = nutrients required in relative large amounts (Nitrogen, carbon, phosphorus) • Micronutrients = nutrients needed in smaller amounts

37. Housekeeping Items • Before I start with other items, I would like to introduce Sacia Burton, who is the coordinator of Solutions, the sustainability club on campus. She is also helping to organize a conference on sustainability on March 15th. She’s here to tell about activities that might lend themselves to your action project. • I appreciate Jeff stepping in in my absence. • I was having trouble getting e-mails out to the class. Did everyone get the new assignment? • The web site has been updated, including assignment instructions, except for today’s slides (later today). • Just a reminder that the due date for project outlines is 2/6. • Tomorrow the Faculty of Social Science is hosting a welcome back pizza social in Building 355, Room 211 from noon to 2. • The Career Day event for Geography is next Wednesday (29th) from 10:00 to 11:00 in Room 217.

38. Landscape ecologists study geographic areas with multiple ecosystems • Conservation biology = study the loss, protection, and restoration of biodiversity FIGURE 5.12 Landscape = larger than an ecosystem and smaller than a biome Patches = form the landscape, and are distributed spatially in complex patterns (a mosaic)

39. 3 minute quiz (2 marks) Name_________ Describe and explain two of the three reasons why Earth is habitable.

40. 3 minute quiz (2 marks) Name_________ Describe and explain two of the three reasons why Earth is habitable. Answer: (1 mark for each complete answer, half marks for partial answers) • Distance from the Sun, results in moderate surface temperature • Oxygen rich atmosphere, provides protection from UV radiation • Abundant water, essential for life and climatic processes

41. Remote sensing and GIS are important tools FIGURE 5.13 Remote sensing technologies allow scientists to create a complete picture of the landscape Geographic information system (GIS) = computer software used in landscape ecology research Can analyze how elements within the landscape are arranged to help make planning and land-use decisions

42. Nutrients circulate via biogeochemical cycles • Nutrient (biogeochemical) cycle = the movement of nutrients through ecosystems • Atmosphere, hydrosphere, lithosphere, and biosphere • Reservoirs = where nutrients reside for varying amounts of time • Sources = reservoirs that release more nutrients than they accept • Sinks = accept more nutrients than they release • Flux = movement of nutrients into or out of reservoirs, which change over time and are influenced by human activities

43. The rock cycle (Lithosphere) Rock cycle = The heating, melting, cooling, breaking and reassembling of rocks and minerals Rocks help determine soil chemistry, which influences ecosystems

44. Plate tectonics shapes Earth’s geography • Plate tectonics = process that underlies earthquakes and volcanoes and that determines the geography of the Earth’s surface FIGURE 5.6

45. Plate tectonics shapes Earth’s geography • Plate tectonics leads to: • Volcanic outgassing: releases carbon dioxide (CO2), water vapour (H2O) and other gasses • Weathering: releases minerals

46. The hydrologic cycle FIGURE 5.15

47. The hydrologic cycle influences all other cycles • Water is essential for biochemical reactions and is involved in nearly every environmental system • Oceans are the main reservoir (97% of water) • Precipitation = condensation of water vapor as rain or snow • Evaporation = water moves from aquatic and land systems to air • Transpiration = release of water vapor by plants • Evapotranspiration = the total flux of water vapor from the the Earth’s surface to the atmosphere

48. Figure 9.16 Groundwater • Aquifers = underground reservoirs of porous rock and soil that hold groundwater • Groundwater = water found underground beneath layers of soil

49. Figure 9.16 Groundwater • Water table = the upper limit of groundwater held in an aquifer • Water may be ancient (thousands of years old) • Lakes and streams where the water table reaches the surface

50. Our impacts on the hydrologic cycle are extensive Damming rivers increases evaporation and infiltration Altering the surface and vegetation increases runoff and erosion Spreading water on agricultural fields depletes rivers, lakes and streams Removing forests and vegetation reduces transpiration and lowers water tables Emitting pollutants changes the nature of precipitation Overdrawing groundwater for drinking, irrigation, and industrial use