Presentation on theme: "Major Ecosystems of the World. Terrestrial Biomes Biome = a particular physical environment that contains a characteristic assemblage of plants & animals,"— Presentation transcript:
Major Ecosystems of the World
Terrestrial Biomes Biome = a particular physical environment that contains a characteristic assemblage of plants & animals, soils, and climate
Terrestrial Biomes… Biomes are large, and encompass many interacting ecosystems and climatic zones Type of biome is controlled by temperature and precipitation: –In polar biomes, cold temps. dominate –In tropical biomes, precipitation dominates
Vertical Zonation: (Elevation Effect) Vegetation and organisms vary with elevation up a mountain as temps get colder, wind gets stronger, shade diminishes, etc.
Tundra…synopsis Very short growing season Little precipitation (10-25 cm / yr) Permafrost Low species diversity
TUNDRA Key locations: most land areas above 60° North latitude; coastlines of Greenland, Northern Iceland, Northern Canada, N. Russia –Alpine tundra is similar in temps but at tops of mountain ranges, so other differences occur.
Tundra… Climate: long, harsh winters, very short summers with only 50 – 160 “growing days”; very little precipitation (cold air suppresses precip.) with most of it during summer; snow predominates landscape, along with broad, shallow lakes and ponds, marshes, bogs, sluggish streams
Tundra… Soils: tundra soils are geologically young (glacier laid deposits), and are nutrient poor, very little organic matter (dead leaves, animal droppings); soil contains permafrost and only melts at upper layers in summer; topography generally flat;
Tundra… Vegetation: low species richness; low primary productivity, very few plants occur. Permafrost limits depth of roots, thereby preventing woody plants from developing; Tundra dominated by mosses, lichens, grasses, and sedges (grass-like plants), some dwarf trees;
Tundra Important Animals: lemmings, voles, weasels, arctic foxes, snowshoe hares, snowy owls, ptarmigan, musk oxen are year- round inhabitants; caribou return in summer, along with migratory birds; mosquitoes, black flies, deerflies all survive winter as eggs or pupae; all animals live “on the edge” and have acclimated to extremely harsh conditions; almost no reptiles or amphibians exist in the tundra.
Tundra… Human impacts: Make a list please. Think of what human activities occur directly in the tundra. Also, what activities do we engage in outside the tundra that also influence the tundra?????? Research, ask questions.
TAIGA (Boreal Forest)...synopsis Short growing season Low precipitation (~50 cm / yr) Dominated by conifers (spruce, fir), but also has aspen, birch
Taiga (Boreal Forest) Taiga – located just south of the tundra, where evergreen trees begin to dominate the landscape; Key locations/Other: occur mainly in Russia and Canada; covers 11% of earth’s land; stretches across most of North America and Eurasia; no southern hemisphere counterpart
Taiga… Climate: severe, very cold winters; little precipitation, though more than tundra (about 50 cm per year)
Taiga… Soils: very acidic, mineral poor soils; does contain deep layer of decomposed pine needles, spruce needles; soil contains patchy permafrost, especially at northernmost extreme of biome; many kettle lakes and ponds filling in pits left by glacial ice chunks
Taiga Vegetation: Conifer trees (cone-bearing evergreens) such as black and white spruce; balsam fir, eastern larch dominate; some deciduous trees (shed leaves in autumn) exist; Conifers excel due to drought resistance properties (needles have minimal surface area, limit water loss); northern winter months can be very dry, as snow seldom melts to provide usable water;
Taiga… Important Animals: some large mammals like caribou, wolves, bear, moose during winter (south from tundra); many small mammals like rodents, rabbits, lynx, mink, sable; birds are abundant in summer, migrate south in winter; insects of many types abundant; few amphibians or reptiles.
Taiga (Northern Boreal Forest) Human impacts: One of the human impacts should be incredibly obvious to you….there’s lots of trees in the Taiga!
Temperate Rain Forest Key Locations/Other: northwest coast of North America (Oregon, Washington, Idaho, & British Columbia (Canadian province)
Temperate Rain Forest Climate: high annual precipitation (200 – 380 cm); proximity to coast moderates seasons (small seasonal temperature fluctuations); winters mild, summers cool, very short drier season
Temperate Rain Forest Soils: relatively nutrient poor soils, but more organic content than taiga or tundra; forest litter of needles and branches takes years to decompose due to cool temperatures;
Temperate Rain Forest Vegetation: Large evergreen trees such as western hemlock, Douglas fir, western red cedar, Sitka spruce, western arborvitae; rich in epiphytic vegetation – smaller plants that grow on the trunks of trees and carpet the ground, including mosses, lichens, ferns. Some deciduous shrubs such as vine maple.
Temperate Rain Forest Important Animals: species richness is very high (one of worlds most diverse biomes); squirrels, wood rats, mule deer, elk, birds, many reptiles and amphibians, plus many large mammals of other biomes present here
Temperate Rain Forest Human Impacts:
Temperate Deciduous Forest…synopsis Hot summers, cold winters Moderate precipitation ( cm / yr) Dominated by oaks, hickory, maple Commonly converted to agriculture
Temperate Deciduous Forest: Key Locations/Other: NE USA, Europe, Asia (Mid-latitudes)
Temperate Deciduous Forest: Climate: moderate precipitation ( cm annually); hot summers & cold winters
Temperate Deciduous Forest: Soils: thick layer of humus (organic material) in topsoil; deep, clay-rich lower layer (subsoil); minerals leached by infiltrating water to clay layer if not absorbed into plant roots
Temperate Deciduous Forest: Vegetation: dominated by broad-leaved hardwood trees (oak, hickory, beech) in the northern areas (NE & mid-eastern USA); broad-leaved evergreens (magnolia) take over in the southern portions of this biome; dense canopies can form in undeveloped areas of this biome
Temperate Deciduous Forest: Important Animals: In Europe & N. America, logging and land- clearing for development and agriculture have removed native mammals such as puma, wolves, bison; some remain in varying numbers such as deer, bear; small mammals like rodents and many birds now dominate.
Temperate Deciduous Forest: Human Impacts: Think of what percentage of the world lives within this biome!
Grasslands…synopsis Hot summers, cold winters Low to moderate precipitation (25-75 cm / yr) Dominated tallgrass or shortgrass prairies Heavily converted to agriculture
Grasslands: Key Locations: Tallgrass prairies occur in parts of Illinois, Iowa, Minnesota, Nebraska, Kansas, other Midwestern states; Shortgrass prairies occur in eastern Montana, S. Dakota, etc.; Ukraine, parts of China, etc.
Grasslands: Climate: Summers are hot, winters are cold, rainfall is variable and can change dramatically from year to year, with average precipitation of 25 – 75cm. Tallgrass prairies are moist, shortgrass prairies are dry with grasses that are more drought resistant
Grasslands Soils: considerable organic material due to grasses dying off each winter and adding humus; roots and rhizomes of grasses can eventually form a thick mat under the surface, forming sod; nutrients remain near surface in low precipitation areas, but are leached in wetter zones
Grasslands… Vegetation: moister areas are known as “tallgrass prairies”, with few trees but grasses of various types growing in abundance to heights above 6 feet; drier areas are called “shortgrass prairies”, with smaller grasses.
Grasslands Important Animals: Originally, many grazing mammals existed here, including bison, pronghorn elk, with predators such as wolves, coyotes; smaller animals like prairie dogs and their predators like foxes, birds of prey, etc. also existed, many grouse, birds, snakes, lizards, insects abound;
Grasslands… Human Impacts: Think of the dust bowl….what happened? Why did it happen?
Chaparral…synopsis Dry summers, mild winters Frequent fires Dominated by short pines, evergreen shrubs, scrub oak (but varies worldwide)
Chaparral: Key Locations/Other: Occur in N. American southwest (including California), Mediterranean, Australia, New Zealand
Chaparral… Climate: called “Mediterranean” climate, with very mild winters with abundant precipitation, but very dry summers. Usually occur in hilly areas adjacent to coast; chaparral is type of vegetation that dominates California
Chaparral… Soils: thin, usually infertile, rocky landscape, fires common in late autumn
Chaparral… Vegetation: drought-resistant evergreen shrubs, pine or scrub oak shrubs (3 m tall max.); takes on a lush, green appearance in winter (rainy), with a barren, dry look in summer; fire-adapted plants which grow in nutrients left by burning;
Chaparral… Important Animals: mule deer, chipmunks, wood rats, lizards, many bird species Human Impacts:
Deserts…synopsis Wide daily variations in temperature Very dry (<25 cm precipitation / yr) Sparse plant coverage
Deserts… Key Locations/Other: U.S. Southwest including Arizona, New Mexico, California’s Mohave Desert; Sahara in Africa, etc. –Usually centered near 30 degrees N or S latitiude due to sinking air, high air pressure, and dry conditions
Deserts: Climate: Extremely dry; found in both temperate (cold deserts) and tropical (warm deserts) environments; Lack of water vapor results in temperature extremes (really hot during daytime, very cold at night); precipitation less than 25 cm annually;
Deserts… Soils: low in organic material due to lack of plants, high in mineral content (NaCl, CaCO3, CaSO4) due to lack of leaching; mineral concentrations can be so high that they are toxic to plants; soil is generally exposed to wind
Deserts: Vegetation: some deserts have virtually no plants at all; others contain cacti, giant saguaro (type of cactus), yuccas, Joshua trees, sagebrush; desert plants have spines or thorns to discourage foraging by animals, also built to store water for long periods of time
Desert: Important Animals: small animals mostly, including insects, frogs & toads, desert reptiles include desert tortoise, iguana, Gila monster, Mohave rattlesnake; mammals such as gerbils, kangaroo rats, mule deer, jackrabbits, kangaroos in Australian deserts; carnivores include birds of prey, fox, etc.;
Deserts… Human Impacts:
Savanna…synopsis Precipitation cm / yr, but very seasonal with extended dry periods Dominated by grasses, with occasional trees African most famous for herds of wildebeest, antelope, zebra
Savanna: Key Locations/Other: African savanna most notable; others include S. America, W. India, and N. Australia
Earth’s Major Biomes Climate: Basically like a tropical grassland area; low rainfall (perhaps a short rainy season) with long dry periods; seasons regulated by precipitation since temps stay consistent all year; annual precipitation is cm;
Savanna: Soils: low in essential nutrients; strongly leached during short rainy seasons; rich in aluminum – to the point of toxicity to plants in many areas;
Savanna… Vegetation: mostly grasses with occasional acacia trees (thorny), trees and grasses have fire and/or drought protective features like huge underground root systems enabling them to survive drought
Savanna: Important Animals: herds of hoofed animals such as wildebeest, giraffe, zebras, elephants; plus predators such as lions, hyenas.
Savanna… Human Impacts:
Tropical Rain Forests
Tropical Rain Forests…synopsis Very high precipitation cm / yr Very nutrient- poor soil Extremely high primary productivity Extremely high species richness
Tropical Rain Forests: Key Locations/ Other: Central and South America, Africa, southeast Asia
Tropical Rain Forests: Climate: temperatures are warm throughout the year, with precipitation almost every day; very warm, very moist conditions; annual precipitation of cm; transpiration from lush tree growth provides much of the moisture.
Tropical Rain Forests: Soils: soil is very mineral poor due to massive leaching from extensive rainfall; plenty of bacteria, fungi, detritus-eating insects quickly decompose organic litter leaving very little organic material in the soil; roots of plants quickly absorb whatever remains for the health of the plants themselves
Tropical Rain Forests… Vegetation: very productive biome, plants thrive despite somewhat poor soil because of warm temps and plenty of moisture; species richness is most of any biome, with thousands and thousands of different species of plants; trees include evergreen flowering plants, along with extensive epiphytes including mosses, ferns, orchids, etc. other epiphytes grow in the bark or leaves of their hosts; three distinct levels (stories) in a fully developed tropical rain forest including crown (tops of trees), middle story (canopy of leaves, little sunlight), and the ground level (no sunlight); Ground plants adapted to climbing to reach available light.
Tropical Rain Forests… Important Animals: Most abundant biome for insects, reptiles, amphibians, birds very brilliantly colored, mammals include monkeys, sloths, some elephants
Tropical Rain Forests… Human Impacts: These were discussed first week of school…this was one of our “9 big issues” that we explored.
Interaction of Terrestrial and Aquatic Biomes Most land biomes are bordered by or contain aquatic biomes Interactions between land and water are significant (runoff, erosion, biotic factors, etc.) Protection of aquatic ecosystems helps terrestrial biomes; vice-versa…