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Announcements. 1. WISE Presents WILDFIRE & TREE POPULATION DYNAMICS IN THE BOREAL FOREST Speaker: Dr. Ed Johnson , Professor of Ecology, Department of Biological Sciences, Director of the Kananaskis Field Stations, University of Calgary DATE: Wednesday, October 8, 2003

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    1. Announcements 1. WISE Presents WILDFIRE & TREE POPULATION DYNAMICS IN THE BOREAL FOREST Speaker: Dr. Ed Johnson, Professor of Ecology, Department of Biological Sciences, Director of the Kananaskis Field Stations, University of Calgary DATE: Wednesday, October 8, 2003 TIME: 4:00 p.m. LOCATION: University of LethbridgeAnderson Hall, Room 100

    2. 2. The Society for College and University Planning Do you want to learn more about sustainability and how to make a campus green?Live Telecast hosted by: The U of L Energy Management Sustainability Committee This event will address sustainability and its importance, the role of higher education, strategies, and implementation. Thursday, October 9, 2003 at 10:00 AM (sharp!) Anderson Hall Room 115.

    3. Some Review: Small Scale Winds Daytime

    4. Night Source: Ahrens, 2001

    5. Mountain Valley Breezes Daytime The sun heats the hillslope, causing air to move up the slope Night Night radiation cools the slopes Cooler, denser air moves downslope Source:

    6. Chinook Winds Cooling At MALR 6°C/km Warming At DALR 10 °C/km Warming At DALR 10 °C/km Cooling At MALR 6°C/km Cooling At DALR 10 °C/km X X VANCOUVER LETHBRIDGE 12°C 8°C More sensible heat

    7. Review: Geostrophic Winds Effect of Air temperature on 500 mb heights

    8. Wind flows along Isobars PGF counterracted by inertial Coriolis Force

    9. Global Climate Systems and Biomes

    10. Weather vs. Climate • Weather • Condition of the atmosphere at any place and time • • Climate • Characteristic behaviour of weather over time • Includes averages and extremes • • Climatology is the study of climate • Climatic regions: zones with characteristic weather patterns • Empirical (statistics) or genetic (causative) classification • Eg. Köppen-Geiger Climate Classification System (1928)

    11. Climographs LETHBRIDGE, AB VANCOUVER, BC

    12. Determinants of climate: • Distribution and seasonal variation of solar insolation intensity (zenith angles and daylength) • Atmospheric and oceanic global circulation patterns • Controls of temperature: altitude and latitude, land-water heating differences, cloud cover, polar front • Controls on precipitation: distribution of pressure systems, lift mechanisms (convergence, convection, orographic, frontal), location of ITCZ, subtropical high pressure, jet streams

    13. Effect of Altitude Source: Solomon, 2000

    14. Effect of Latitude and Cloud Cover

    15. Global Circulation Patterns

    16. Climate Distribution Classification systems: Köppen-Geiger, Thornthwaite (not shown) A Tropical - equatorial regions C Mesothermal – eg. Mediterranean, marine W. coast D Microthermal – eg. humid continental, subarctic E Polar H Highland – cooler than surroundings B Dry – deserts and steppes See Figure 6-4

    17. A Tropical Climates Straddle equator: 20N to 20S Coldest month is above 18C Consistent daylength, small zenith angles Includes tropical rainforest, tropical monsoon and tropical savanna

    18. 1. Tropical Rain Forest Climate • Warm and moist • Thunderstorms – local convection in convergent ITCZ • All months receive more than 60mm • Precipitation pattern follows migration of ITCZ • Two wetter seasons near equator, one wetter season near tropics • High rainfall and solar insolation sustain lush, evergreen, broadleaf tree growth • High leaf area index (LAI) • Dark canopy floor with sparse vegetation • Rapid decomposition – more nutrient mass in vegetation than soil

    19. Rainforest Climograph Manokwari, New Guinea Little variability in average monthly temperature Driest month receives more than 100 mm of rainfall Source:

    20. Tropical Rain Forest Vegetation Layers in the Tropical Rain Forest Canopy Source:

    21. The Tropical Rain Forest The world’s most biologically-diverse biome

    22. Layers in the Tropical Rain Forest Canopy • Emergents • Trees “emerge” from the forest canopy • Exposed to high light, fluctuating temperatures, higher winds • Huge trees (up to 70m) with massive, buttressed trunks • Seed dispersal often by wind • Home to many birds and animals looking for safety from predators (eg. eagles, bats, monkeys, snakes, butterflies)

    23. Buttressed Trunks Helps support large tree biomass, weight of water and epiphytes

    24. Canopy Layer • Continuous layer (about 45 m) • Most have buttressed trunks • Especially high diversity of plants and animals • Same tree found once or twice per square kilometre • Lianas (vines) connect trees • Epiphytic vegetation common -28,000 species (eg. mosses, bromeliads, ferns, orchids) • Abundant fauna (eg. monkeys, sloths, bats, treefrogs, ants, beetles, parrots, hummingbirds and snakes)

    25. Understorey Layer • Receives 2-5% of incident light (blocked by canopy) • Understorey plants photosynthesize most efficiently under low light (low respiration rates) • Layer consists of small trees (eg. dwarf palms) and seedlings of taller trees • Low wind: insect pollination, strong smelling and conspicuous flowers often on trunks • Abundant fauna (eg. insects, snakes, frogs, parakeets, leopards, jaguars etc.)

    26. Forest Floor • Approximately 1% of light incident upon the canopy • 100% relative humidity, less temperature variation • Rapidly-decomposing organic matter • Few flowering plants • Fungi thrive on decomposing organic matter • Large mammals forage for roots and tubers (eg. tapirs) • Many insects (eg. termites, cockroaches, beetles, centipedes, millipedes, scorpions and earthworms)

    27. Global Distribution of Tropical Rain Forests

    28. Deforestation • >50% already gone (pasture, timber, fuelwood, farming) • Approximately 169,000 km2 lost each year • Fire clears land for agriculture (food production, rubber, coffee etc.) • Slash and burn – soil nutrient reserves quickly exhausted • Destruction generally along transportation networks •  Tropical Forestry Action Plan (FAO, UNDP, WB, WRI) • Remote sensing and GIS play key role in monitoring

    29. 2. Tropical Monsoon and Savanna Climates • Tropical Monsoon Climates • Rainfall from ITCZ affects regions for 6-12 months of the year (eg. text example Yangon, Myanmar) • Seasonal variation in winds and precipitation • 1 or more months have less than 60mm of precipitation • Evergreen broadleaf trees grade toward thorn forests along drier margins with savanna

    30. Tropical Monsoon Climograph Dry season during the Northern Hemisphere winter Wet season during the summer

    31. Tropical Savanna Climates • ITCZ effect for <6 months of the year • Winters are dry (subtropical high pressure) • Summers are wet (influence of ITCZ) • Tropical cyclones possible near east coasts • Grasslands dominate: scattered, drought-resistant trees • Text example: Mérida, Mexico (relatively wet) and Kenya

    32. Tropical Savanna Distribution

    33. Savanna Climograph Long dry season during the Southern Hemisphere winter Wet season during the summer

    34. Vegetation in the Tropical Monsoon and Savanna Climate Zones: • Tropical Seasonal Forest and Scrub • Poleward transition from tropical rain forest to grasslands • Monsoonal forestsopen woodlandsscrub woodlandthorn forestsdrought-resistant scrubgrassland • Leaf loss and dry season flowering during seasonal moisture deficits

    35. Monsoonal forests: • Discontinuous, 15 m high canopy • Denser undergrowth • Orchardlike parkland with grassy openings in drier sectors • Flat-topped acacia trees become common in drier zones • Examples: Caatinga (Brazil), Chaco (Paraguay), Brigalow (Australia), Dornveld (S. Africa) • Wildlife: elephants, large cats, rodents, ground-dwelling birds • Koalas and cockatoos in Australia

    36. Monsoon Forest of India Increased light penetration compared to lowland rain forest Discontinuous Canopy and Lower LAI Source: I. de Borhegyi FAO

    37. Vegetation of the tropical savanna • Large expanses of grassland, interrupted in areas by trees and shrubs • Trees and shrubs are xerophytic (small, waxy, thick leaves) • Most expansive in Africa (Serengeti plains, Sahel) • also Los Llanos (Venezuela), Campo Cerrado, Pantanal (Brazil) • Fires common during the dry seasons (beneficial if early) • Affected by desertification • Soils richer in humus than tropical rain forests: sorghum, wheat, peanuts can be grown • Home to large land mammals in Africa: lion, cheetah, zebra, giraffe, buffalo, gazelle, wildebeest, antelope, rhinoceros and elephant

    38. The Serengeti Plain (Savanna)

    39. El Nino Southern Oscillation Interannual climatic variability at the global scale Caused by changing atmospheric and oceanic circulation in the tropical Pacific Ocean

    40. See

    41. C Mesothermal Climates • 1.  Humid Subtropical Hot Summer Climate • Influenced by maritime tropical air masses in summer • Continental polar and maritime tropical air masses mix in fall/winter/spring: frontal precipitation • Convectional precipitation in moist, unstable summer airmass • Tropical cyclones near coasts in summer and fall • 1000 – 2000 mm/yr total

    42. Examples: southeast U.S., southeast China, southern Japan, • northern Argentina • Broadleaf and mixed forest Source: M.K. House, near Tallahassee, Fl.

    43. Humid Subtropical Winter Dry Climate • Similar to above, but dry in winter • Heavy precipitation in summer • Circulation in winter prevents moist, tropical air mass interaction with pressure systems • eg. much of southern China, eastern South Africa • Broadleaf and mixed forest, but largely deforested • (see Figure 6-11)

    44. 3. Marine West Coast Climates • Mild winter and relatively cool summer • Winter maximum of precipitation, especially in southern zones • Heavy precipitation in mountains (may exceed 4000 mm/yr) • Precipitation varies at low altitude: much more precipitation in northern portions of the Marine West Coast Climate than in the south • Dominated by maritime polar air masses but unusually mild for their latitudes • Coastal fog is common