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
Chapter 6 Major Ecosystems of the World Lecture Outline ► Terrestrial Biomes Define Biome Representative terrestrial biomes (characteristics – physical & biological) Human impacts on biomes Impact of altitude & latitude ► Aquatic Ecosystems Environmental factors that affect ecosystems Representative aquatic ecosystems Human impacts on aquatic ecosystems What is a biome? ►A broad, regional type of ecosystem that has distinct climate and soil conditions and a distinctive kind of biological community adapted to those conditions. Biomes ► Include: Many interacting ecosystems Terrestrial ecology ►Community to ecosytems to landscape to biome What is important in determining a biome – Temperature and precipitation Also influenced by landforms (especially mountains). Major Biomes of World Vertical Zonation ► Going up a mountain is like traveling to the poles ► What happens as you go up a mountain? ► Important differences between latitude and elevation biomes Tundra (Arctic or Alpine Tundra) ► Location – High mountains or latitude ► Vegetation –treeless, low vegetation ► Growing season - short ► Seasons – cold, harsh winters, frost any month. ► Water is locked up in the snow and ice Arctic Tundra ► ► ► ► ► ► Low productivity, low diversity, low resilience Permafrost – soil is frozen year round Vegetation – no deep roots, small plants Heave/settlement - due to freeze & thaw Climate – very cold, little percipitation Drainage – none, clayey soils Alpine Tundra ► Where is this biome? Located at high altitudes ► How is it different from Artic Tundra? More solar radiation Very hot temperatures during day in summer Lots of wind & gravelly soil Well draining Tundra Fauna ► Year round – Lemmings, voles, weasels, & artic foxes ► Migratory – Musk ox, caribou, alpine mountain goats, mountain sheep, birds, insects Tundra Flora ► Dwarf vegetation – dwarf willows, dwarf birches, sedges, grasses, mosses, lichens ► All very small Human effects on Tundra ► Oil and natural gas wells – roads, pipelines, drilling locations ► Mineral excavation – mining ► Climate Change – melting permafrost, warmer temperature. Taiga (Boreal forests, Conifer forests) ► Taiga Found in northern hemisphere only On edge of artic tundra Low productivity & low resilience Peat formed by cold temperatures, very wet soil in summer, acids from fallen needles ► Boreal Forests Found between 45 & 60 degrees north latitude Moist & cool Many streams & wetlands Taiga Flora & Fauna ► Taiga Flora – Black & white spruce, balsam fir, eastern larch, aspen, & birch ► Taiga Fauna – Caribou, wolves, bears, moose, rodents, rabbits, lynx, sable, mink, migratory birds, insects Temperate Rain Forests (Conifer Forests) ► Location – NW North America, SE Australia, S. South America ► Precipitation – High; condensation from dense canopy ► Flora – Mosses, lichen, & Ferns cover branches ► Olympic National Park Temperate Rain Forest Flora & Fauna ► Flora – Large Evergreen trees – western hemlock, douglas fir, western red cedar Epiphytes – what the heck is that? Mosses, orchids, lichen, fern ► Fauna – squirrels, wood rats, mule deer, elk, birds, amphibians, reptiles Human Impact Taiga, Boreal Forests & Temperate Rainforest ► Logging – increased erosion, siltation of rivers & creek ► Peat Mining – used as an energy source, long lasting damage Temperate Deciduous Forest (Broad-Leaved) ► Precipitation - significant ► Key adaptation – ability to produce summer leaves that are shed for winter ► Rich topsoil with underlying clay Temperate Deciduous Forest Flora & Fauna ► Flora – Oak, maple, birch, beech, elm, ash, small shrubs, flowers, herbaceous plants ► Fauna – puma, wolves, bison, deer, bear, and many small animals and birds Grasslands (Prairies & Savannas) ► ► ► ► Location – dry continental climates of Great Plains, Russian Steppes, African Savanna, South American Pampas Richest soil in world Flora – few trees except along rivers, grass Wildfires - helps maintain the grasslands. Grassland Flora & Fauna ► Flora – Grasses both short and tall Herbaceous flowering plants Savannas - acacia ► Fauna Prairies – bison, wolves, deer, elk, antelopes, migratory birds Savannas – wildebeast, antelope, giraffe, zebra, elephants, lions, & hyenas. Human Impact on Grasslands & Savannas ► Agriculture – 90% of North American grassland has vanished Rarest biome in North America ► Rangeland Both North American grassland and African savannas are being used for cattle Chaparral (Mediterranean, Thorn Shrub) ► ► ► ► ► Climate – warm, dry summers & cool, moist winters Location – California, Mediterranean Coast, SW Australia, Central Chile, South Africa Covers small area Highly desired for human population – great climate Drier areas – African Sahel, northern Mexico, Great Basin Chaparral – Flora & Fauna ► Flora – Varies around the world Evergreen shrubs with small, leathery leaves Scrub Oak, small trees, Fire Resistant ► Fauna – Mule deer, wood rats, chipmunks, lizards, birds Thorn shrub – snakes, lizards, rodents, antelopes, gazelle, rhinos, giraffes Human affects on Chaparral ► Preferred location of humans to live ► Crowding out the indigenous flora & fauna Deserts ► Precipitation – infrequent & unpredictable ► Location – 30 degrees north & south latitude, leeward side of rain shadow ► High in mineral content Desert Flora & Fauna ► Flora – Perennials, annuals, cacti, yuccas, Joshua trees, sage brush ► Fauna – amphibians, reptiles, rodents, mule deer, jack rabbits, kangaroo Human impacts on Deserts ► War ► Development into agricultural areas ► Habitation Tropical Rainforests ► ► ► ► ► Climate – warm all year round, rains daily Location – Equatorial Regions Soil – old, thin, acidic and nutrient poor Where are all the nutrients? In the canopy of the forest Rapid decomposition and recycling of dead organic matter Rainforests Flora & Fauna ► Flora – flowering plants Three distinct stories of plants ► Tall Trees ► Middle Story ► Lower Story Epiphytes, lianas 1/3 to ½ of all species of plants & insects ► Fauna Reptiles, amphibians, birds, sloth’s, monkeys, elephants. Human impacts on Rainforests ► Logging – Agriculture – plants and livestock Wood harvesting – furniture, heat/cooking ► Mining Erosion Water contamination ► 1-1/2 acres are destroyed a second; some scientist think we will lose them all in 40 years. Aquatic Ecosystems ► ► ► Freshwater – rivers, streams, lakes, ponds, marshes, swamps Estuaries – where rivers meet oceans or seas Marine Intertidal Benthic Neritic Oceanic Freshwater Ecosystems ► Vary significantly ► Influenced by: Local Climate Soil Surrounding Ecosystems Affects from upstream Rivers and Streams ► Flowing ecosystem ► Changes greatly from source to mouth ► Groundwater can intersect ► Depend on land for energy - detritus Rivers and streams ► Features of a river Flora & Fauna of Rivers & Streams ► Greatly influenced by surrounding terrestrial ecosystems ► Varies widely depending on velocity of water, temperature, water quality Impact of Humans on Streams and Rivers ► Pollution ► Dams ► Development Lakes and Ponds ► Littoral zone – most productive zone, where photosynthesis is greatest, . ► Limnetic Zone – open water beyond littoral zone; extends down as far as light penetrates. Microscopic organisms ► Profundal Zone – Beneath Limnetic zone, shallow lakes don’t have, food drifts from above. Lake Zones Thermal Stratification in Lakes ► Layering in lakes determined by how much light penetrates ► Thermal stratification: Summer sunlight penetrates water -> warms surface, less dense Cool water stays on bottom, more dense Line that marks change in density is called a thermocline In fall, surface water becomes colder than lower water and the warmer water below rises (fall turnover) In spring, reverse happens after ice melts (spring turnover) Thermal Stratification in lakes Marshes & Swamps Wetlands ► Areas covered by shallow water for part of year (plants can grow in water) ► Soil rich in nutrients ► Grasslike plants dominate ► Swamps – wetlands with trees ► Marshes – wetlands without trees ► Bogs & Fens – areas without trees that accumulate peat, low productivity Estuaries ► Bays or semi-enclosed bodies of brackish (salty but less than seawater) ► Contain rich sediment carried from upstream. Marine Ecosytems ► Divided zones: into several Intertidal Benthic Pelagic ► Neritic ► Oceanic Pelagic Environment ► Determined by depth of water ► Neritic province – area from shoreline to depth of 200 meters Oceanic province – area in open ocean with water depths greater than 200 meters Intertidal Zone ► Shoreline area that is between low and high tides ► High levels of light and nutrients ► Abundant oxygen ► Highly productive but stressful environment Benthic Environment ► Ocean floor ► Mostly sand and mud ► Zones: Abyssal benthic zone – extends from 4000 to 6000 m Hadal zone – extends deeper than 6000 m. Flora of Marine Ecosystem ► Kelp ► Coral Reefs – must have light ► Sea Grasses – 95% not eaten; instead decomposed by bacteria Neritic Province ► Shallow water close to shore ► Upper reaches comprise the euphotic zone: Extends to depth of 200 meters Enough light penetrates to support photosynthesis Phytoplankton are producers, zooplankton are primary consumers, nekton are secondary consumers, carnivorous nekton are tertiary consumers Oceanic Provinces ► ► ► ► Largest marine environment Deep water organisms feed on marine snow (organic debris that floats down from upper reaches) Organisms adapt to dark environment (called aphiotic) Many organisms can produces own light Human Impact on Marine Environments ► ► Damage to coral reefs: High salinity Pollution Overfishing Tourism Global warming Pollution - Plastic Development Mining Oil Drilling Overfishing Oceans