Forest Biomes Coniferous Forests Deciduous Forests Rain Forests
Forest Biomes -Coniferous Forests -Deciduous Forests -Rain Forests
Forests • Cover 30% of Earth land surface • Rain forests are most complex and diverse biome
Coniferous Forests • Coniferous means “cone-bearing” • Coniferous trees, (conifers, ) produce seed cones that hold the seeds • The leaf of a conifer is the needle • Needles help conserve (save) water: they are long, thin and covered in thick wax • Most conifers are evergreen, meaning they do not lose all their leaves at one time during the year. It happens slowly through the entire year • Examples: Pine, hemlock, fir, spruce, and cedar are common in coniferous forests
• Where • Mostly in subarctic regions of North America, Europe, and Asia • Climate • Warm summers, 2 -5 months with average temperature of • Long, cold, winters with average temperature of • 12 -60 inches of precipitation/yr (rain in summer, snow in winter)
• Animal life: • Small herbivores are seed eaters; ex: mice, squirrels, jays, rodents, other birds • Insects are common in summer when soil is moist and poorly drained • Large herbivores feed on plants and bark; ex: moose, elk, beaver, and snowshoe hares, bears (brown, grizzly) • All have thick body covers to protect from cold
Deciduous Forests • Temperate zones-climates with four, welldefined seasons • Most forests in temperate zones are deciduous • Deciduous trees shed their leaves during a particular season of the year • Where: eastern half of North America, and the middle of Europe. There are many deciduous forests in Asia. South America has two big areas of deciduous forests in southern Chile and Middle East coast of Paraguay. There are deciduous forests located in New Zealand, and southeastern Australia also.
Deciduous Forests • Climate • Temps vary greatly, 86 degrees Fahrenheit in summer to -20 degrees Fahrenheit in winter • Precipitation is about 30 -60 inches per year • Tree adaptations • Have to adapt to varying climate • During fall, tree sheds its leaves and becomes dormant. (not active) This helps conserve water during winter • Trees feed off of their stored food until spring, when grow new leaves
• • Deciduous examples: maple, oak, beech, ash, hickory, birch 3 layers Canopy-highest layer, made up of upper branches and leaves of tall trees • The canopy captures most of sunlight, but some filters through to bottom layers • Understory-under canopy, made of trees that are younger and smaller than canopy, also has shrubs • Floor-mosses, ferns, and other plants that grow on ground layer Photo from mbgnet. net
• • • Animals and organisms Fungi, (decomposers), insects live in leaf litter and fallen trees Birds, mice, small mammals feed on them White-tailed deer are common, Reptiles, amphibians, in warm forests Predators include: wolves, mountain lions, birds of prey, foxes Photo courtesy of web. nestucca. k 12. or. us
Rain Forest • Rain forests can be found in tropical zones-located at latitudes near the equator • Receive direct rays from sun most of the year • Climate • Avg 25 degrees celcius ALL year • Growing season last all 12 months • Precipitation is rain, except at high mountaintops • 200 -450 cm/year • ***climate does not vary or change much in the rain forest through the year • Structure • Dense canopy of evergreen, broadleaf trees supported by at least 200 cm rain /year
• trees include: cypress, balsa, teak, mahogany • Ecologists have found 700 species of trees in just 10 hectares (25 acres) of a rain forest in Borneo • Only 1% of sunlight will filter through to forest floor, plants are sparse on the floor • Dead matter does not contribute much nutrients to the soil b/c they are recycled so quickly in rain forests • This is b/c of the high moisture levels • Nutrients are quickly drawn back into the trees • Topsoil is thin and poor, usually most nutrients are in the top 5 cm • So, tree trunks are wide at the base with buttresses-ridges for support • Roots are shallow • Vines grow up trees to reach sunlight, plants can live directly on trees • These are called arboreal b/c they live in trees. Have adaptations to live in trees
• Organisms and Diversity • Rainforests are the most animal diverse biome • Two reasons: 1)diversity of plants gives high # of niches 2) wide variety of habitats in the different levels of the forest • Habitats vary in each level, each tree, and each part of the tree • Scientists don’t know how many species live in the rainforest • Wilson found 43 species of ants in one tree! • Erwin estimated over 50 million insect species • Scientists continue to find more species everytime they look for more in the rainforest
• Deforestation-destruction of forest as a result of human activity • In 1950, more than 10% of Earth’s land was rainforest • Now, down to 6% and decreasing • Destruction due to developing countries, population growth, logging, farming, mining • Animals habitats are quickly destroyed, especially since the ecosystem is vertical (goes up, not spread out) • One acre cleared will destroy millions of habitats • This (biodiversity loss) is the most serious issue with rainforest destruction
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