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Temperate Rainforests: most trees flare at the base. Vegetation is dense, tall and very green. Temperate rainforests are very lush and wet. It rains a lot in the temperate rainforest, about 100 inches per year. And even more moisture comes from the coastal fog that hovers among the trees. Temperate rainforest are found in the middle latitudes around the globe and have four distinct seasons: Spring, Summer, Fall, and Winter.
Deciduous is a word that means exactly what the leaves on these trees do: change color in autumn, fall off in the winter, and grow back again in the spring. This is adaptation helps trees in the forest survive winter. The average temperature in temperate deciduous forests is roughly 75°F but gets as high as 86°F, depending on the altitude of the forest. Forests higher in the mountains are colder. Deciduous forests receive from 2 to 5 feet of precipitation (both rain and snow) each year. Humidity in these forests is high, from 60% to 80%.
Evergreen: name applied to any plant that retains its foliage through two or more consecutive seasons. In contrast to deciduous plants, which shed their leaves seasonally, evergreens retain their foliage anywhere from 1 to 18 years. Many common varieties, such as spruce, fir, and other members of the pine family, have needle-shaped foliage, but most evergreens are broad-leaved. Some shrubs and trees are both deciduous and evergreen, depending on where they are grown.
Grasslands: a grassland is a grassy, windy, partly-dry biome, in essence, it's a sea of grass. Almost one-fourth of the Earth's land area is grassland. In many areas, grasslands separate forests from deserts. Deep-rooted grasses dominate the flora in a grassland; there are very few trees and shrubs in a grassland, less than one tree per acre. There are many different words for grassland environments around the world, including savannas, pampas, campos, plains, steppes, prairies and veldts.
Shrublands: and woodlands are forests that have either trees or shrubs that are widely spaced and do not form a closed canopy. Shrublands or chaparrals have frequent fires because they are typically dry during the summer months.
Savannas: are hot, seasonally dry grasslands with scattered trees. Savannas are intermediate between a grassland and a forest. Savannas are located in the dry tropics and the subtropics, often bordering a rainforest. Savannas have an extended dry season followed by a rainy season. Fires often occur that clear the region of seedlings, which allows the grasses to dominate the area.
Deserts: cover about one fifth (20 percent) of the earth's land area. The desert is a harsh environment with very little rainfall and extreme temperatures. Desert plant life is not abundant; neither is animal life. Deserts are very dry regions with limited plant and animal life. The biggest desert is northern Africa's Sahara Desert.
Some deserts get both very hot (during the day) and very cold (during the night,
when temperatures can drop well below freezing). Some deserts, however, are
always cold (for example, the Gobi Desert in Asia, and the desert on the continent
of Antarctica).
Tundra: is the coldest of all the biomes.
Tundra comes from the Finnish word "tunturia", meaning treeless plain. It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short
growing seasons. Dead organic material functions as a nutrient pool. Arctic tundra is located in the northern hemisphere, encircling the north pole and extending south to the coniferous forests of the taiga. The arctic is known for its cold, desert-like conditions. The growing season ranges from 50 to 60 days. The average winter temperature is -34° C (-30° F), but the average summer temperature is 3-12° C (37-54° F) which enables this biome to sustain life. A layer of permanently frozen subsoil called permafrost exists, consisting mostly of gravel and finer material. Alpine tundra is located on mountains throughout the world at the highest altitudes where trees can grow.
Tropical Rainforests: are very dense, warm, wet forests. They are havens for millions of plants and animals. Rainforests are extremely important in the ecology of the Earth. The plants of the rainforest generate much of the Earth's oxygen. These plants are also very important to people in other ways; many are used in new drugs that fight disease and illness. Temperature is on average 20-25° C and varies little throughout the year, the average temperatures of the three warmest and three coldest months do not differ by more than 5 degrees. Precipitation is evenly distributed throughout the year, with annual rainfall exceeding 2000 mm. Soil is nutrient-poor and acidic. Decomposition is rapid and soils are subject to heavy leaching. Canopy in tropical forests is multilayered and continuous, allowing little light penetration. Flora is highly diverse: one square kilometer may contain as many as 100 different tree species. Trees are 25-35 m tall, with buttressed trunks and shallow roots, mostly evergreen, with large dark green leaves. Plants such as orchids, bromeliads, vines (lianas), ferns, mosses, and palms are present in tropical forests. Fauna include numerous birds, bats, small mammals, and insects.
Students objective include:
1. interpret the effects of the Earth's Tilt
2. describe the distribution of heat
3. identify the world biomes
