UNIT FOUR Chapter 52 An Introduction to Ecology and the Biosphere Ecology the scientific study of the interactions between organisms and the environment ecologists study o Ecological interactions occur at a hierarchy of scales that Chapter 52 1 Earth s climate varies by latitude and seasons and is changing rapidly Global Ecology Biosphere the global ecosystem the sum of all the planet s ecosystem and landscapes Global ecology examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere Landscape Ecology Landscape or seascape is a mosaic of connected ecosystems Landscape ecology focuses on the factors controlling exchanges of energy materials and organisms across multiple ecosystems Ecosystem Ecology Ecosystem is the community of organisms in an area and the physical factors with which those organisms interact Ecosystem ecology emphasizes energy flow and chemical cycling between organisms and the environment Community Ecology Community is a group of populations of different species in an area Community ecology examines how interactions between species such as predation and competition affect community structure and organization Population Ecology Population is a group of individuals of the same species living in an area Population ecology analyzes factors that affect population size and how and why it changes through time Organismal Ecology Organismal ecology which includes the sub disciplines of physiological evolutionary and behavioral ecology is concerned with how an organisms structure physiology and behavior meet the challenges posed by its environment Global Climate Patterns Earth s curved shape causes latitudinal variation in the intensity of Tropics those regions that lie between 23 5 degrees north latitude and The intense solar radiation near the equator causes a pattern of air sunlight 23 5 degrees south latitude circulation and precipitation Climate Climate the long term prevailing weather conditions in a given area o Four physical factors temperature precipitation sunlight and wind are important features of climate Macroclimate patterns on the global regional and landscape level Microclimate very fine localized patterns o i e a community of organisms that live in the microhabitat beneath a log Global Climate Patterns Determined by the input of solar energy Earth s movement in space This pattern establishes temperature variations cycles of air and water movement and evaporation of water Regional and Local Effects on Climate Climate patterns are affected by many factors i e bodies of water or mountains Seasonality sun Season cycles are due to the earth s tiled axis and the rotation about the Other factors include belts of wet or dry air solar radiation day length temperature the changing angle of the sun Bodies of Water Ocean currents influence climate along the coasts by heating and cooling Because of the high specific heat of water bodies of water regulate the the land climate of the nearby land Mountains Mountains influence air flow over land Mountains affect the amount of sunlight reaching an area and thus local temperatures and rainfall Every 1 000 meter increase in elevation produces a temperature drop 6 degrees C Microclimate Influenced by shade altering evaporation from soil changing wind patterns or any other features within the environment i e a tree casting shade Abiotic nonliving referring to the physical and chemical properties of an environment o Temperature light water nutrients Biotic living factors in the environment Global Climate Change Any large scale change in earth s climate affects the biosphere o i e burning fossil fuels and deforestation Researchers are currently making predictions as to the future of our Because of climate change many species are moving their geographic climate location Chapter 52 2 The structure and distribution of terrestrial biomes are controlled by climate and disturbance Biomes major life zones characterized by vegetation type in terrestrial biomes or by the physical environment in aquatic biomes Climate and Terrestrial Biomes Terrestrial biomes show strong latitudinal patterns in where they are Climograph a plot of the annual mean temperature and precipitation in found a particular region o i e grasslands are dry and forests are generally warmer A climograph is only based on averages not pattern so if two areas received the same amount of rain in a month it may not mean the same thing one area may have rained every day and the other area it may have rained only because it was in season and every other season it is dry o This same principle can be applied to temperature or abiotic characteristics General Features of Terrestrial Biomes Each biome is characterized by microorganisms such as fungi or animals that have adapted to the particular environment Ecotone the transition from one type of habitat or ecosystem to another such as the transition from a forest to a grassland Canopy the uppermost layer of vegetation in a terrestrial biome The species composition of each kind of biome varies from one location to another Disturbance and Terrestrial Biomes Disturbance a natural or human caused event that changes a biological community and usually removes organisms from it Disturbances such as fires and storms play a pivotal role in structuring many communities As a result of disturbances biomes often exhibit extensive patchiness with several different communities represented in a single area Tropical Forest Biome Rainfall is relatively constant in tropical rain forests Precipitation is highly seasonal in tropical dry forests Desert Biome Occur in bands near 30 degrees north and south latitude Precipitation is low and highly variable Typically hot in the day and cool at night Low vegetation and typically inhabited by snakes scorpions lizards or ants Savannah Biome Is warm year round but more seasonal than in tropical rain forests found in parts of Africa Australia and regions in South America Large mammals i e wildebeests Scattered vegetation very grassy Chaparral Biome Occurs in mid latitude coastal regions on several continents Temperate Grassland Biome Located in Africa Hungary Argentina Uruguay Russia and north America Very seasonal receive cold winters and hot summers Northern Coniferous Forest Biome Extends in a broad band across northern north America and Eurasia to the edge of the arctic tundra Largest terrestrial biome on earth Temperate
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