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Ecosystems, Biomes & Succession Terrestrial & Aquatic 2015 ECOLOGY • The study of how organisms interact with one another and with their nonliving environment. Figure 3-2 Important Ecological Terms • • • • • • • Organism Cell Eukaryote Prokaryote Species Asexual Reproduction Sexual Reproduction • • • • • • Organisms and Species Organisms Populations Communities Ecosystems Biomes Biosphere Figure 3-3 Other animals 281,000 Known species 1,412,000 Insects 751,000 Fungi 69,000 Prokaryotes 4,800 Plants 248,400 Protists 57,700 Fig. 3-3, p. 52 BIOMES: CLIMATE AND LIFE ON LAND • Biomes – large terrestrial regions characterized by similar climate, soil, plants, and animals. • Temperature • Precipitation • Latitude vs. altitude BIOMES: CLIMATE AND LIFE ON LAND Figure 5-9 BIOMES: CLIMATE AND LIFE ON LAND • The major factors determining Biome type are precipitation and temperature. Figure 5-10 BIOMES: CLIMATE AND LIFE ON LAND • Parallel changes occur in vegetation type occur when we travel from the equator to the poles or from lowlands to mountaintops. Figure 5-11 DESERT BIOMES • 30% of Earth’s land • Evaporation exceeds precipitation. • Little vegetation. – Found in tropical (Sahara), temperate (Mojave) and cold regions (Gobi). • Succulent plants • Deep vs. widespread roots • Some plants secrete toxins into soil (sagebrush) • Small animals DESERT BIOMES • Tropical, temperate and cold deserts. Figure 5-12 GRASSLANDS AND CHAPARRAL BIOMES • • • • • Tropical grasslands (savannas) Temperate grasslands (prairies) Chaparral (Mediterranean, S. Cal) Wet/dry season Many are fire-maintained (many plants contain oils) GRASSLANDS AND CHAPARRAL BIOMES • Most grasslands have alkaline soil (pH of ?) • Temperate grasslands have nutrient-rich soil Figure 5-14 Polar Grasslands • Tundra - covered with ice and snow except during a brief summer (permafrost) • Seasonal wetlands • Lots of migratory animals & mosquitoes Figure 5-17 Chaparral • Moderate climate • Dense thickets of spiny shrubs • Subject to periodic fires Figure 5-18 FOREST BIOMES • Tropical rainforest • Tropical deciduous forest • Temperate deciduous forest • Temperate rain forest • Coniferous forest (boreal, taiga). Figure 5-19 Tropical Rain Forest • • • • • Heavy rainfall High biodiversity Broadleaf evergreens Nutrient-poor soil High decomposition rate • Greatest concentration of nutrients in vegetation Figure 5-20 Temperate Deciduous Forest • Most of the trees survive winter by dropping their leaves, which decay and produce a nutrient-rich soil • Moderate rainfall Figure 5-22 Evergreen Coniferous Forests • Mostly cone-bearing evergreen trees - keep their needles yearround • Insulating factor helps the trees survive long and cold winters • Cone-shape helps shed snow • Acidic soil Figure 5-23 Temperate Rain Forests • Coastal areas (Calif., Oregon, Washington) - huge conebearing evergreen trees such as redwoods and Douglas fir • Cool moist environment • Soil may be more acidic so pH is ? Figure 5-24 MOUNTAIN BIOMES • High-elevation islands of biodiversity • Snow-covered peaks - reflect solar radiation • Release water to lower-elevation streams and ecosystems. Figure 5-25 Natural Capital Degradation Desert Large desert cities Soil destruction by off-road vehicles Soil salinization from irrigation Depletion of groundwater Land disturbance and pollution from mineral extraction Fig. 5-26, p. 123 Natural Capital Degradation Grasslands Conversion to cropland Release of CO2 to atmosphere from grassland burning Overgrazing by livestock Oil production and off-road vehicles in arctic tundra Fig. 5-27, p. 123 Natural Capital Degradation Forests Clearing for agriculture, livestock grazing, timber, and urban development Conversion of diverse forests to tree plantations Damage from off-road vehicles Pollution of forest streams Fig. 5-28, p. 124 Natural Capital Degradation Mountains Agriculture Timber extraction Mineral extraction Hydroelectric dams and reservoirs Increasing tourism Urban air pollution Increased ultraviolet radiation from ozone depletion Soil damage from off-road vehicles Fig. 5-29, p. 124 CLIMATE: A BRIEF INTRODUCTION • Weather • Climate - Latitude and elevation help determine climate. • Warm front • Cold front • High pressure • Low pressure • Adiabatic cooling FRONTS the movement of warm and cold masses of air creates the weather, and when the two clash, it often rains. A warm front is defined as the transition zone where a warm air mass is replacing a cold air mass. Warm fronts generally move from southwest to northeast and the air behind a warm front is warmer and more moist than the air ahead of it. When a warm front passes through, the air becomes noticeably warmer and more humid than it was before. FRONTS • A cold front is defined as the transition zone where a cold air mass is replacing a warmer air mass. Cold fronts generally move from northwest to southeast. The air behind a cold front is noticeably colder and drier than the air ahead of it. When a cold front passes through, temperatures can drop more than 15 degrees within the first hour. FRONTS PRESSURE SYSTEMS • The air associated with a high pressure system sinks down from above and warms as it does so and is very stable. • A high pressure system (anticyclone), is a system of closed isobars surrounding a region of relatively high pressure. When compared with low pressure systems, highs tend to cover a greater area, move more slowly and have a longer life. • When the high pressure system is located over land the weather will be typically dry and free of cloud. PRESSURE SYSTEMS • A low pressure system (cyclone) develops where relatively warm air ascends from the Earth's surface. These are systems of closed isobars surrounding a region of relatively low pressure. • As the rising air cools, clouds will begin to form. The instability of the air will produce quite large vertical development of cumuliform clouds with associated rain showers (such as cumulonimbus cloud). Adiabatic Cooling • Adiabatic cooling deals with the cooling of parcels of air as they rise, or are forced up, through the atmosphere. Adiabatic cooling Earth’s Current Climate Zones Figure 5-2 Solar Energy and Global Air Circulation: Distributing Heat Climate is affected by: • 1) Uneven heating of the earth’s surface • 2) Seasonal changes in temperature and precipitation • 3) Earth’s rotation • 4) Unique properties of air & water Diagram Figure 5-3 Coriolis Effect • Deflection of air due to the rotation of the earth & friction between air & Earth – less effect near the equator (fewer hurricanes within 5 degrees) Coriolis Effect Trade Winds Figure 5-4 Convection Currents • Drive day-today weather patterns • Rainshadow Effect Figure 5-5 Convection Cells • Distribute heat & moisture • 6 Vertical currents at different latitudes : • Hadley Cell – 0 – 30 - tradewinds • Ferrel Cell – 30-60westerlies • Polar Cell- 60 – 90 easterlies Figure 5-6 El Nino/ENSO • Equatorial winds weaken along Eastern Pacific • Surface water warms • No upwelling • Increased flooding in e. Pacific • Drier western Pacific • Fewer Atlantic hurricanes World Map La Nina • Exaggerated normal pattern • Cooler water than normal along eastern Pacific • Drier eastern Pacific • Flooding along western Pacific • More Atlantic hurricanes Topography and Local Climate: Land Matters • • • • Rain Shadow effect Microclimates (forests, cities) Sea breezes Land breezes Figure 5-8