Presentation on theme: "“Land Biomes of the World” Mrs. Hartge’s Science Class"— Presentation transcript:
1“Land Biomes of the World” Mrs. Hartge’s Science Class
2The biosphere is the total of all of Earth's ecosystems The global ecosystem is called the biosphereIt is the sum of all the Earth's ecosystemsThe biosphere is the most complex level in ecologyFigure 34.2A
3The biosphere is self-contained except for energy obtained from the sun and heat lost to spaceEach habitat has a unique community of speciesFigure 34.2B
4Abiotic Factors Abiotic factors are those non-living physical and chemical factors which affect the ability of organisms to survive and reproduce.
5Abiotic FactorsAbiotic factors vary in the environment and determining the types and numbers of organisms that exist in that environment.light intensitytemperature rangetype of soil or rockpH level (acidity or alkalinity)water availabilitydissolved gaseslevel of pollutant
6Physical and chemical factors influence life in the biosphere The most important abiotic factors that determine the biosphere's structure and dynamics includesolar energywatertemperature
7Disturbances such as fires, hurricanes, and volcanic eruptions are also abiotic factors Figure 34.4
8Biotic FactorsBiotic factors are all the living things or their materials that directly or indirectly affect an organism in its environment. This would include organisms, their presence, parts, interaction, and wastes. Factors such as parasitism, disease, and predation (one animal eating another) would also be classified as biotic factors.
9Natural selection adapts organisms to abiotic and biotic factors Organisms are adapted to abiotic and biotic factors by natural selectionThe presence and success of a species in a particular place depends upon its ability to adaptNatural selection adapts organisms to abiotic and biotic factorsBiotic factors include predation and competitionFigure 34.5
10Regional climate influences the distribution of biological communities Climate often determines the distribution of communitiesEarth's global climate patterns are largely determined by the input of solar energy and the planet's movement in space
11Most climatic variations are due to the uneven heating of Earth's surface This is a result of the variation in solar radiation at different latitudesNorth Pole60º NLow angle of incoming sunlight30º NTropic of CancerSunlight directly overhead0º (equator)Tropic of Capricorn30º SLow angle of incoming sunlight60º SAtmosphereSouth PoleFigure 34.6A
12The seasons of the year result from the permanent tilt of the plant on its axis as it orbits the sun MARCH EQUINOX (equator faces sun directly)JUNE SOLSTICE (Northern Hemisphere tilts toward sun)DECEMBER SOLSTICE (Northern Hemisphere tilts away from sun)SEPTEMBER EQUINOXFigure 34.6B
13What is a Biome?Plants and animals don't live in isolation, but they live together with other plants and animals in an interdependent group called an ecological community. If you think about it for a moment, you will realize that all of the plants and animals in a particular ecological community must be adapted to the same climate so that they can all live in the same location.
14A distinct ecological community of plants and animals living together in a particular climate is called a "biome." Scientists have divided the broad spectrum of climates and ecological communities found on Earth into biomes in different ways - some with many divisions, some with only a few.
15Major terrestrial biomes 30º NEquator30º STropical forestPolar and high-mountain iceTemperate deciduous forestSavannaChaparralConiferous forestDesertTemperate grasslandTundra (arctic and alpine)Figure 34.9
16Tropical forests cluster near the equator Several types of tropical forests occur in the warm, moist belt along the equator Tropical RainforestFigure 34.10
17Savannas are grasslands with scattered trees Drier, tropical areas and some nontropical areas are characterized by the savanna Tropical SavannahFigure 34.12
18Deserts are defined by their dryness Deserts are the driest of all terrestrial biomesThey are characterized by low and unpredictable rainfall DesertDesertification is a significant environmental problemFigure 34.13
19Temperate grasslands include the North American prairie Temperate grasslands are found in the interiors of the continents, where winters are coldDrought, fires, and grazing animals prevent trees from growingFarms have replaced most of North America's temperate grasslandsFigure 34.15
20Deciduous trees dominate temperate forests Temperate deciduous forests grow where there is sufficient moisture to support the growth of large trees Deciduous ForestNearly all of the original deciduous forests in North America have been drastically altered by agriculture and urban developmentFigure 34.16
21Coniferous forests are often dominated by a few species of trees The northern coniferous forest, or taiga, is the largest terrestrial biome on Earth TaigaFigure 34.17
22The taiga is characterized by long, cold winters and short, wet summers Coastal coniferous forests of the Pacific Northwest are actually temperate rain forests
23Long, bitter-cold winters characterize the tundra The arctic tundra lies between the taiga and the permanently frozen polar regions Arctic TundraIt is a treeless biome characterized by extreme cold, wind, and permafrostPermafrost is continuously frozen subsoilFigure 34.18