This week, we move into the living world (i.e., the Bio and Anthro-spheres). As always post questions and thoughts that you have as engage this weeks materials on the Bio-geography, Cultural geography, and Geo-linguistics. As before, you may want to post about your answer to one of this week’s Guided Report questions.
Identify a region and a cultural geography or geo-linguistics or other social/cultural aspects that links to the region. In your discussion, include historical background and unique features.
No Slide Title Introduction to Climatic regions and terrestrial biomes Updated 1/20/18 Overview: Climate sets the “stage” for ecological systems- Plant and wildlife will thrive within a set range of temperature and precipitation patterns. Climate is largely determined by latitude (i.e. incident solar radiation), but oceanic and atmospheric currents also shift heat and water around the world in somewhat predictable patterns. Finally local physical geography (i.e. presence of water bodies, mountains, and biological features such as presence of forests also effect local or micro-climate features. Climate regions can be distinguished geographically evaporation, heat at Equator --> rising moist air --> rain prevailing onshore winds --> humidity large land mass in North --> severe winter (microthermal) low pressure (Intertropical Convergence Zone) Relationship between Atmospheric Pressure and Biomes in an Idealized continent high pressure high pressure prevailing offshore winds --> dry Monthly average surface temperatures from 1961–1990. This is an example of how climate varies with location and season Updated Koppen-Geiger Climate Map * Köppen classification of climates * Major categories based on average & extremes of temperature, precipitation, humidity. * A - Humid Tropical: warm, rainy or less-rainy; monsoon, rainforest, savanna regions. * B - Arid: warm or cool; steppe, desert. * C - (Humid) Mesothermal: mild winter, humid or dry; eg. southeastern US (humid subtropical), "Mediterranean", Marine West Coast. * D - (Humid) Microthermal: severe winter; humid; mild or hot summer; subarctic; eg. US Midwest. * E - Polar: cold; tundra, ice-cap * H - Highland: climate and organisms vary with elevation. * Köppen classification of climates We will consider the fundamental Köppen classification of climates as they apply to California and the US over the next 32 slides. Recall that the major categories based on average & extremes of temperature, precipitation, humidity. * A - Humid Tropical: warm, rainy or less-rainy; monsoon, rainforest, savanna regions. * B - Arid: warm or cool; steppe, desert. * C - (Humid) Mesothermal: mild winter, humid or dry; eg. southeastern US (humid subtropical), "Mediterranean", Marine West Coast. * D - (Humid) Microthermal: severe winter; humid; mild or hot summer; subarctic; eg. US Midwest. * E - Polar: cold; tundra, ice-cap * H - Highland: climate and organisms vary with elevation. California is a unique place; * Collision of tectonic plates: land topography & ocean produce multiple climatic zones & biomes * Mt. Whitney (14,496') only 80 miles from Death Valley (-282') * Driest spot in USA (Bagdad in Mojave Desert) * Record for highest temp in Western Hemisphere (Furnace Creek in Death Valley, 134° F) * 33-50% of plants are endemic; >50% of animals are endemic * Has ~25% of all plant species in US & Canada * SD County has more rare & endangered species than any other US county Torrey pine (Pinus torreyana): native to only La Jolla/Del Mar and Santa Rosa Is. Updated Koppen-Geiger Climate Map of North America Climatic zones Mesothermal: Marine West Coast Mesothermal: Mediterranean Highland Arid: Steppe Arid: Desert Mediterranean ("scrub"; chaparral, dry shrub & woodland) Temperate mixed forest (coniferous- deciduous) Desert Evergreen coniferous forest Grassland Biomes (= "Vegetation" = "Habitats") Grassland: vernal pools; greatly modified Desert Scrub: chaparral Scrub: oak woodland Global "scrub" or chaparral: Mediterranean climate, dry western edge of continents, ~30° North & South lichen A - Humid Tropical: coolest month above 65° F * Tropical rainforest -- climate (Af) & biome * Equatorial (eg. Amazon, Congo, Indonesia): constant sunrise @ 6 am, sunset @ 6 pm * High year-round insolation, precipitation * Seasons marked by rainfall, not temperature; no true dry season * Many organisms --> dead organic matter is quickly broken down & used --> little build-up of soil * Selva: tall trees block sunlight; little undergrowth * Jungle: dense undergrowth (eg. vines, shrubs); edge of selva & rivers, clearings selva (Central America) jungle (Indonesia) Why high species diversity in tropical rainforests? * Tropical rainforests = 6% of land surface, but hold 50+% of species * ESA theory (Energy-Stability-Area) * High input of solar energy --> heat & evaporation * Heat, humidity & rainfall promote plant growth --> piggybacking (eg. many small organisms living on different parts of plants) * Stable climate: no need to migrate or hibernate --> specialize in local habitat; small species ranges * Large area: forests of Brazil, Africa, Indonesia provided large "arenas" of evolution without catastrophic disturbances * Evolutionary stability: have not been affected by Ice Ages * Tropical monsoon climate (Am) -- usually forest biome * India, northern S America * Summer onshore wind (heavy rain); winter offshore wind * Short dry season, unlike tropical rainforest * Tropical savanna -- climate (Aw) & biome * South America, Africa * Grassland with scattered trees & shrubs * Heavy rain season, and seasons of sporadic rain * Venezuela: llanos; Brazil: campos Monsoon: rice fields (India) Wildebeest on savanna (Kenya) B - Arid: mean annual temp. above 65° F; precipitation less than potential evaporation * Desert -- climate (BW) & biome * N Africa (Sahara), Arabia, Australia, China (Gobi), US/Mexico (Sonoran) * High pressure belt; often in "rain shadow" * Irregular, unreliable rainfall (ie. less than 10") * Dry, clear air * Intense sunlight during day * Few clouds to absorb Earth's heat radiated at night --> Large daily changes in temperature (ie. 125 F day to 60 F night) * Soil: nutrient-poor, salty (water evaporation), sandy, basic (pH > 7) * Low primary productivity * Xerophytic plants: adapted to extreme drought California deserts * rain shadow effect * less than 10" rain per year * Bagdad: no rain at all for two years (1912-14; just before "Rainmaker") Colorado Mojave Great Basin (Modoc Plateau) Great Basin (Basin & Range Province Great Basin Desert * "Cold Desert" * winter rain with snow * alot of interior drainage into a salty lake * Great Basin sagebrush: adapted to dry, sandy soil; total biomass may exceed the coast redwoods Mojave Desert * "High Desert" despite Death Valley * winter rain * Joshua Tree, creosote bush * tectonic activity: basin dropped relative to surrounding uplifting mountains * Badwater Basin: -282 feet, lowest in Western Hemisphere Colorado Desert * "Low Desert" * part of large Sonoran Desert * winter & summer rain, growing season * Salton Trough ("Sea"); Anza-Borrego * cactus; trees * Steppe -- climate (BS) & biome (grassland) * N America (Great Plains), S America (pampas), S Africa (veldt), Central Asia (steppe) * More rain than deserts (ie. 10-20" annually) * Often peripheral to deserts & humid climates Great Central Valley * 430 miles long * geologically, filled in by sediment run-off from surrounding mountains --> alluvial soils with deep water infiltration * drained by Sacramento & S. Joaquin R. * confluence of these rivers is just below sea level --> large delta/wetland (flood plain) * rain shadow formed by Coast Ranges --> south of Fresno = desert (< 10"="" rain)="" san="" joaquin="" r.="" sacramento="" r.="" valley="" grassland="" *="" ~70%="" of="" grass="" plant="" is="" below="" ground="" *="" resilient="" to="" drought,="" fire,="" herbivores="" *="" long="" roots;="" can="" store="" nutrients="" *="" grow="" from="" stem="" base="" (on="" or="" under="" ground),="" not="" from="" stem="" tip="" *="" underground="" shoots="" (rhizomes)="" *="" seeds="" are="" resistant="" to="" drying="" --=""> long-term storage (wheat, rice) * perennial: persists year-round above ground. * annual: life cycle is less than one year (ie. seed --> sprout/grow --> flower --> release seeds --> die). Modification of the Central Valley * 90-99% of Central Valley communities have been lost (eg. grasslands, freshwater marshes, vernal pools) * agriculture * overgrazing * introduced plants C - Humid Mesothermal: warmest month above 50° F; mild winter * Mediterranean -- climate (Cs) & biome (shrubs, some trees) * Mediterranean, California (chaparral), Chile, S Africa, Australia * Hot, dry summer * Fires: clear space for new growth; recycle nutrients * Plants go dormant (estivation) * Winter rains * Coastal --> ocean influence (maritime fog) * Sclerophyllous plants ("hard-leaf"; drought-resistant; waxy coating) * California: introduced scrub plants do well * Mediterranean: grapes, olives, figs, citrus, fennel, mustard * Australia: eucalyptus * S. Africa: "ice plants" chaparral; "scrub" oak woodland California: chaparral/scrub Coastal sage scrub (eg. Torrey Pines at Del Mar). * Low elevation. * "Soft chaparral": dominant plants with soft, flexible leaves/stems (eg. sage, sumac). * Low-lying shrubs. * Fog is important source of water. * Contains desert plants (eg. prickly-pear). * Adaptations: drought-deciduous; succulent. Black sage (Salvia mellifera) * In mint family: strong odor, square stem. * Black stems. * Humid subtropical -- climate (Cfa); forest, grasslands * Southeastern US, China * Humid (onshore moist air); year-round rain (ie. 25-100" per year) * Warm summers * High primary productivity --> good farm/plantation land * Marine West Coast -- climate (Cfb, Cfc) & biome (forest) * Northern Europe, northwestern US * Mild summers & winters * Year-round precipitation * Heavy clouds & fogs --> fog drip important to many plants Marine West Coast * heavy fog (fog drip) * heavy rainfall Coast redwood (Sequoia sempervirens) * Endemic to California * Tallest tree in world (365 feet) * Lumber is sturdy, resistant to termites * Require much moisture: 60 inches from rain, 12 inches from fog drip * Fog from ocean is important --> coast redwoods do not occur too far inland * Prefer wet, sandy soils * Seeds fall from cones after fire * Contrast to Giant sequoia (Giant Sierra redwood): * Sierra Nevada * Brittle lumber * Largest living thing (ie. volume) D - Humid Microthermal: warmest month above 50° F; cold winter (coldest month below 32° F); abundant annual precipitation * Humid Continental, Hot Summer -- climate (Dfa, Dwa); deciduous forest, grassland * Northern US, southern Canada * Humid summers * Good crop productivity * Humid Continental, Mild Summer -- climate (Dfb, Dwb); mixed or coniferous forest, grassland * Russia, eastern Canada * Shorter growing season * Subarctic -- climate & biome (northern coniferous forest = taiga = boreal forest) * Northern continental masses * Short, cool summer * Long, very cold winter * Permafrost: frozen subsoil E - Polar: warmest month below 50° F; very cold winter; abundant annual precipitation * Tundra * Short, cold summer * Permafrost * Lichens; low-lying plants * Ice-cap * No summer * All months below freezing (32° F) * No vegetation H - Highland: climate & biome changes with elevation (zonation) Sierra Nevada ("snowy range") * 400 miles long * mountain zonation: each 1,000 feet in altitude = 300