Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Terrestrial Biomes Objective: CLIMATE: a brief review Weather is a local area’s short-term physical conditions such as temperature and precipitation. Climate is a region’s average weather conditions over a long time. Latitude and elevation help determine climate. • Latitude: distance from the equator • Longitude: east to west distance from meridian • Elevation: distance above sea level Earth’s Current Climate Zones Figure 5-2 Distributing Heat Global air circulation is affected by the uneven heating of the earth’s surface by solar energy seasonal changes in temperature and precipitation Figure 5-3 Spring (sun aims directly at equator) Winter (northern hemisphere 23.5 ° tilts away from sun) Solar radiation Summer (northern hemisphere tilts toward sun) Fall (sun aims directly at equator) Fig. 5-3, p. 102 Coriolis Effect • Definition: the acceleration of an object based on rotation • Counterclockwise in the northern hemisphere • Clockwise in the southern hemisphere Coriolis Effect Global air circulation is affected by the rotation of the earth on its axis Figure 5-4 Convection Currents Global air circulation is affected by the properties of air water, and land. Figure 5-5 LOW PRESSURE Cool, dry air HIGH PRESSURE Heat released radiates to space Condensation Falls, is compressed, warms and precipitation Rises, expands, cools Warm, dry air Hot, wet air Flows toward low pressure, picks up moisture and heat HIGH Moist surface warmed PRESSURE by sun LOW PRESSURE Fig. 5-5, p. 103 Convection Cells Heat and moisture are distributed over the earth’s surface by vertical currents, which form six giant convection cells at different latitudes. “Warm air rises, cold air sinks” Figure 5-6 Cell 3 North Cold, dry air falls Moist air rises — rain Polar cap Arctic tundra Evergreen 60°coniferous forest Temperate deciduous forest and grassland 30°Tropical Desert Cell 2 North Cool, dry air falls Cell 1 North deciduous forest 0°Equator Tropical deciduous 30°forest Tropical rain forest Desert Temperate deciduous 60°forest and grassland Cell 1 South Cool, dry air falls Cell 2 South Polar cap Cold, dry air falls Moist air rises, cools, and releases Moisture as rain Moist air rises — rain Cell 3 South Fig. 5-6, p. 103 Ocean Currents Ocean currents influence climate by distributing heat from place to place and mixing and distributing nutrients. Figure 5-7 Topography and Local Climate: Land Matters Interactions between land and oceans and disruptions of airflows by mountains and cities affect local climates. Figure 5-8 Windward: the side from which the wind is blowing Prevailing winds pick up moisture from an ocean. On the windward side of a mountain range, air rises, cools, and releases moisture. On the leeward side of the mountain range, air descends, warms, and Releases little moisture. Dry habitats Moist habitats Leeward: the side sheltered or away from the wind Fig. 5-8, p. 105 BIOMES: CLIMATE AND LIFE ON LAND Different climates lead to different communities of organisms, especially vegetation. Biomes – large terrestrial regions characterized by similar climate, soil, plants, and animals. BIOMES: CLIMATE AND LIFE ON LAND Biome type is determined by precipitation, temperature and soil type Figure 5-10 BIOMES: CLIMATE AND LIFE ON LAND Parallel changes occur in vegetation type when we travel from the equator to the poles or from lowlands to mountaintops. Figure 5-11 DESERT BIOMES Deserts are areas where evaporation exceeds precipitation. Deserts have little precipitation and little vegetation. Found in tropical, temperate and polar regions. Desert plants have adaptations that help them stay cool and get enough water. DESERT BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts. Figure 5-12 Box 3: Tropical Desert Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical Desert Directions: Fill in your Biomes Graphic Organizer as we go! Fig. 5-12a, p. 109 Box 3: Temperate Desert Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate Desert Fig. 5-12b, p. 109 Box 3: Polar Desert Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (°C) Polar Desert Fig. 5-12c, p. 109 DESERT BIOMES The flora and fauna in desert ecosystems adapt to their environment through their behavior and physiology. Figure 5-13 GRASSLANDS AND CHAPARRAL BIOMES Variations in annual temperature (red) and precipitation (blue). Figure 5-14 Box 14: Tropical Savanna Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical grassland (savanna) Fig. 5-14a, p. 112 Box 10: Temperate Grassland Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate grassland Fig. 5-14b, p. 112 Box 16: Arctic Tundra Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Polar grassland (arctic tundra) Fig. 5-14c, p. 112 GRASSLANDS AND CHAPARRAL BIOMES Grasslands (prairies) occur in areas too moist for desert and too dry for forests. Savannas are tropical grasslands with scattered tree and herds of hoofed animals. Temperate Grasslands The cold winters and hot dry summers have deep and fertile soil that make them ideal for growing crops and grazing cattle. Figure 5-15 Temperate Grasslands Temperate tallgrass prairie ecosystem in North America. Figure 5-16 Arctic Tundra Artic Tundra (polar grasslands) are covered with ice and snow except during a brief summer. Figure 5-17 Chaparral Chaparral has a moderate climate but its dense thickets of spiny shrubs are subject to periodic fires. Figure 5-18 FOREST BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar forests. Figure 5-19 Box 13: Tropical Rain Forest Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical rain forest Fig. 5-19a, p. 116 Box 9: Temperate Deciduous Forest Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate deciduous forest Fig. 5-19b, p. 116 Box 1: Boreal Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Polar evergreen coniferous forest (boreal forest, taiga) Fig. 5-19c, p. 116 FOREST BIOMES Forests have enough precipitation to support stands of trees and are found in tropical, temperate, and polar regions. Tropical Rain Forest Tropical rain forests have heavy rainfall and a rich diversity of species. Found near the equator. Have year-round uniformity warm temperatures and high humidity. Figure 5-20 Tropical Rain Forest Filling such niches enables species to avoid or minimize competition and coexist Figure 5-21 Emergent layer Harpy eagle Toco toucan Canopy Understory Woolly opossum Shrub layer Brazilian tapir Black-crowned antipitta Ground layer Fig. 5-21, p. 118 Temperate Deciduous Forest Most of the trees survive winter by dropping their leaves, which decay and produce a nutrientrich soil. Figure 5-22 Evergreen Coniferous Forests Consist mostly of cone-bearing evergreen trees that keep their needles year-round to help the trees survive long and cold winters. Figure 5-23 Temperate Rain Forests Coastal areas support huge cone-bearing evergreen trees such as redwoods and Douglas fir in a cool moist environment. Figure 5-24 MOUNTAIN BIOMES High-elevation islands of biodiversity Often have snowcovered peaks that reflect solar radiation and gradually release water to lowerelevation streams and ecosystems. Figure 5-25 HUMAN IMPACTS ON TERRESTRIAL BIOMES Human activities have damaged or disturbed more than half of the world’s terrestrial ecosystems. Humans have had a number of specific harmful effects on the world’s deserts, grasslands, forests, and mountains. Human Impacts: Deserts Large desert cities Soil destruction by off-road vehicles Soil salinization (saltiness) from irrigation Depletion of groundwater Land disturbance and pollution from mineral extraction Human Impacts: Grasslands Conversion to cropland Release of CO2 to the atmosphere from burning Overgrazing by livestock Oil production and off-road vehicles in arctic tundra Human Effects: Forests Clearing for agriculture, livestock, timber, and urban development Conversion of diverse forests to tree plantations Damage from off-road vehicles Pollution of forest streams Human Impacts: Mountains Agriculture Timber extraction Mineral extraction Hydroelectric dams and reservoirs Urban air pollution Increased UV rays from ozone depletion Soil damage from off-road vehicles