Presentation on theme: "Biomes Taiga (coniferous forest) Distribution of taiga"— Presentation transcript:
1Biomes Taiga (coniferous forest) Distribution of taiga It covers great parts of North America and Eurasia.
2Biomes Characteristics of taiga Winters are long and cold (-54 to -1 C˚) and summers are short and warm (-1 to 21 C˚).Precipitation is fairly low throughout the year (30-85 centimeters), but snow is frequent during the winter.Most of the precipitation in the taiga falls as rain in the summer.The trees of the taiga are almost evergreen conifers with waxy needle leaves.
3BiomesTaiga biomeTaiga (coniferous forest) biome with conifers
4BiomesTaiga biomeTaiga (coniferous forest) biome in winter
7Biomes Tundra Distribution of tundra It borders the Arctic Ocean (the North pole).
8Biomes Characteristics of tundra The Arctic tundra is the world's youngest biome.It is a treeless region bordering the Arctic Ocean.Conditions in the tundra are severe, Winter temperature often reach -55 ˚C or below, winds can blow between 50 to100 kilometers an hour. Night can last for weeks in winter.During summers, the temperature can drop to freezing, and the growing season may last only a few weeks before a hard frost occurs.Precipitation averages 25 centimeters or less each year.Nevertheless, the tundra support a variety of life; it is carpeted by grasses, small perennial flowers, mosses and lichens.The tundra vegetation supports lemmings, which are eaten by wolves, snowy owls, arctic foxes and grizzly bears.Insects provide food for migratory birds which reach tundra to nest and raise their young during the short summer.
9BiomesTundra biomeTundra biome: The ground is permanently frozen 25 to 100 cmdown so that trees can't grow.
10BiomesTundra biomeTundra biome: During the short summers the top layer of soil maythaw (melt) to let small perennial plants grow and reproduce.
11BiomesTundra biomeDuring summer, the ground of tundra biome is carpetedwith small perennial flowers
12Biomes Tundra biome animals Arctic owl Polar bear Arctic hare Arctic owlPolar bearArctic hareArctic fox
13BiomesTundra biome animalsPenguinCaribouLemmingArctic wolf
14Biomes Deserts Distribution of deserts The desert biome is found mostly around 20˚ to 30˚ north and south of the equator.
15Biomes Characteristics of deserts Deserts are hot and have very little rainfall.Precipitation averages 15 centimeters or less per year.Deserts have widely spaced vegetation and large areas of bare ground.Vegetation includes shrubs, cacti and short woody trees.Plants are adapted to survive hot weather, for example the ability to store and conserve water.Desert animals include lizards, snakes, insects, arachnids, birds, rat and camel.Most desert animals are nocturnal (only active at night) to avoid the sun and heat.
20Aquatic Biomes Characteristics of aquatic biomes or ecosystems Saltwater oceans and seas are the largest ecosystem on Earth.Among the unique properties of water are:water is slower to heat and cool than air. Therefore, temperature in aquatic ecosystems is more moderate than in terrestrial ecosystem.It absorbs a considerable amount of the light energy that powers life.
21Aquatic Biomes Types of aquatic ecosystems There are many different kinds of aquatic ecosystems:Freshwater ecosystems include:riversstreamspondslakesmarshesMarine (saltwater) ecosystems include:coral reefsthe open oceanestuaries
22Aquatic Biomes Freshwater lakes Freshwater lakes vary tremendously in size, depth and nutrient content.Plants and animals live mainly in the shallow zone of the lake; they find abundant light and adequate nutrients.
23Aquatic Biomes Rivers and streams Freshwater ecosystems that have flowing or moving water.Streams have flow of water faster than rivers.Rivers are larger and deeper than streams.RiverStream
24Aquatic Biomes Marine ecosystems Marine waters cover two-thirds of the surface of the Earth.The ocean is divided into zones according to the amount of sunlight they get. The zones are:photic zone (the upper layer of water to a depth of about 200 meters, receives sufficient light to support photosynthesis).aphotic zone (the bottommost zone below the photic zone)
25Aquatic Biomes Costal waters The greatest concentration of life in the oceans is found in the shallow costal water where abundant light and nutrients.Costal waters include:the intertidal zone: the area that is alternatively covered and uncovered by water with the rising and falling of the tides.near-shore zone: relatively shallow, but submerged areas.The abundance of nutrients and sunlight in this zone promotes the growth of a large variety of organisms.
26Aquatic Biomes Coral reefs Coral reefs are most abundant in warm tropical waters (the temperatures range between 22 ˚C and 28 ˚C).Reef-building corals thrive within the photic zone at depth of less than 40 meters, where light penetrates clear water and provide energy for photosynthesis.The corals require light because they harbor photosynthetic unicellular algae called dinoflagellates within their tissues in a mutualistic relationship.The algae give the corals their diverse brilliant color.The skeletons of the corals accumulate over thousands of years, providing shelter and food for the most diverse collection of invertebrates and fish.
27Aquatic Biomes Coral reefs Coral reefs, composed of corals and algae, provide habitat for diverse communities of fish and invertebrates, such as sponges.
28Aquatic Biomes Open ocean Beyond the costal regions lies the open ocean.Most life in the open ocean is limited to the photic zone, where organisms are pelagic (free swimming or floating organisms).with deeper parts of open ocean, the aphotic zone, the pressure increases, the temperature drops and there is less light, or there is no light at all.The food web of the open ocean is dependent on phytoplankton (floating microscopic photosynthetic organisms).Phytoplankton is consumed by zooplankton (floating microscopic animals).Zooplankton serve as food for larger invertebrates and small fish, which are in turn eaten by larger fish and marine mammals.
29Aquatic Biomes Open ocean Phytoplankton Small fish Zooplankton Shark The open ocean supports abundant life in the photic zone, where light is available. Phytoplankton are the producers. Phytoplankton are eaten by zooplankton, represented here by this microscopic copepod (a crustacean).