Biosphere and Its Units ECOLOGY The study of the relationships between organisms and their environment. Not just related to pollution Unifying factor is adaptation.
Biosphere and Its Units Biosphere Area of earth where life exists Most on or within a few meters of earth's surface. Some found 8 km high and some found 8 km below ocean surface. Smaller ecological units Population - all members of a species that live in same area and make up a breeding group Group of deer in a forest, trout in a lake. Community - All populations in an area
Biosphere and Its Units ECOSYSTEM An ecological unit that includes all interacting parts of an environment in an area. Abiotic Factors Nonliving components of an ecosystem. Biotic Factors Living components of an ecosystem.
Biosphere and Its Units ABIOTIC FACTORS Nonliving components of an ecosystem. Light, precipitation, temperature, slope/drainage of land, soil chemistry, and atmosphere. Abiotic factors may interact Stream flooding results in deposition of sediment Changing of river courses Creation of mountains or islands by volcanoes Landslides removing soil.
Biosphere and Its Units BIOTIC FACTORS Living components of an ecosystem. Plants, animals, protists, microorganisms Living things may interact Predation– predator kills prey for food. Symbiosis – relationship between two organisms Usually beneficial to one organism.
Biosphere and Its Units Abiotic and biotic factors may also interact Affect each other. Climate/soils determine type of plants in area; determines animals of area. Plants replenish oxygen - photosynthesis Overgrazing can result in loss of soil.
Ecosystem Structure HABITAT Place where an organism lives - "home" Provides food and shelter. Habitats may overlap NICHE Role or occupation; everything organism does in its habitat Organisms way of life includes habitat, feeding habits, reproductive behavior, and all other biological aspects of the organism. No two organisms can occupy the same niche Habitats overlap, niches do not.
Ecosystem Structure Trophic Levels Energy enters an ecosystem from the sun. Energy flows between organisms when one organism eats another. Trophic Levelis defined by the relationship between what organism eats and what eats it. The feeding level in an ecosystem. Comes from Greek that means "food"
Ecosystem Structure Trophic Levels Producers Autotrophic organisms that make their own food using solar or chemical energy Consumers Heterotrophic organisms that feed on producers either directly or indirectly for their energy. Decomposers Organisms that breakdown organic material and return it to the environment for use by producers Heterotrophic organisms.
Ecosystem Structure PRODUCERS Autotrophic organisms that make their own food using solar or chemical energy. Plants, algae, and photosynthetic bacteria Manufacture all organic nutrients for ecosystem Also called primary producers. Occupy the First Trophic Level Primary Productivity of an ecosystem - rate at which solar energy is converted into organic compounds Gross Primary Productivity - total amount of energy produced, includes energy used by plant for own respiration Net Primary Productivity- rate at which plants store energy not used in plant respiration.
Ecosystem Structure CONSUMERS Heterotrophs that feed on producers either directly or indirectly for their energy. Primary Consumer - feeds on producers Secondary Consumer - feeds on a primary consumer. Consumers may be classified on basis of food type Herbivore- eats primary producers; "Plant eater" Carnivore- eats other consumers; "meat eater" Omnivore– eats both primary producers and consumers; Scavenger- feeds on organisms that recently died.
Ecosystem Structure DECOMPOSERS Breakdown organic material and return it to environment for use by producers Heterotrophic organisms. Process called Decay Includes bacteria, mold, mushrooms Types Saprophytes- obtain their food from dead organisms or the waste products of living organisms Ex - molds, mushrooms Parasites- obtain their food from living organisms Ex - athlete's foot
Ecosystem Structure Energy Flow Energy flows in various patterns in ecosystem. Total energy of one trophic level never flows to next level Food Chain- specific sequence where organisms obtain energy and organic materials from one another. Food Web - interconnected food chains formed due to the complex relationships
Ecosystem Structure FOOD CHAIN Producer Primary Consumer Secondary Consumer Scavenger Grass Deer Puma Vulture
Ecosystem Structure FOOD WEB Hawk Snake Lizard Mouse Bird Grasshopper Rabbit Grass
Ecosystem Structure Ecological Pyramids Complexities of ecosystem are graphed to show the relationship between trophic levels Primary producer at the base with consumer levels above it. Common pyramid models Energy Pyramid Numbers Pyramid Biomass Pyramid
Ecosystem Structure ENERGY PYRAMID Shows that energy is lost at each level Each organism in a given trophic level uses some of energy to carry on its own life functions. Always a loss of energy as heat in any system of energy transfer. Never inverted.
Ecosystem Structure NUMBERS PYRAMID Shows number of organisms at each level Usually an increase in the size of the organisms with each level Normally producer organisms are most numerous; may be inverted Single tree may support thousands of insects and birds
Ecosystem Structure BIOMASS PYRAMID Amount of matter that can be supported at each trophic level. Biomass is the total dry weight of organisms in the ecosystem.
Ecosystem Structure BIOGEOCHEMICAL CYCLES Process where inorganic materials move from atmosphere or soil to living things and back Also called Nutrient Cycles. Water Cycle Nitrogen Cycle Oxygen-Carbon Cycle
Ecosystem Structure WATER CYCLE Movement of water from atmosphere to the earth and back again. Precipitation- movement of water to earth from atmosphere Evaporation- way most water lost from earth's surface to atmosphere. Transpiration- loss water by green plants through their leaves.
Ecosystem Structure NITROGEN CYCLE Process by which nitrogen passes from the atmosphere to organisms and back again Four major processes Nitrogen Fixation - bacteria convert nitrogen gas into ammonium compounds; live in roots of legumes Ammonification- bacteria break down nitrogen- containing amino acids from animal wastes and dead organisms to form ammonia compounds Nitrification - Bacteria oxidize ammonia compounds to produce nitrates and nitrites Denitrification- anaerobic bacteria break down nitrate releasing nitrogen gas back into the atmosphere
Ecosystem Structure OXYGEN-CARBON CYCLE Involves processes of photosynthesis and respiration Photosynthesis removes CO2 from atmosphere and fixes it as glucose and releases O2 Respiration removes O2 from atmosphere and CO2 is released. Normally processes balance each other. Levels of O2 and CO2 remain fairly constant
Ecosystem Structure Since about 1850's fossil fuels consumption has increased Fossil fuels represent stored carbon compounds Combustion of the fuels has increased the CO2 level of the atmosphere. Increased levels of CO2 increase the atmosphere’s ability to trap heat. Greenhouse Effect - an increase in atmospheric temperature due to heat being trapped by the atmosphere. Can change climates and habitats Should be called Global Warming
Terrestrial Biomes BIOME Large area identified by the presence of characteristic plants and animals. Commonly identified by dominant plant life. Don't have definite boundaries Usually have characteristic rainfall and temperatures.
Terrestrial Biomes POLAR BIOMES Surround North and South poles Receive very little precipitation - fresh water scarce Soil is sparse, low in nutrients, frozen much of the year Temperature range - -40o C to 4o C Receive virtually no sunlight for half the year. Arctic Polar Biome Lies over Arctic Ocean Plants - Some flowering plants, mosses, lichens, Animals - Gulls, Walruses, polar bears along Arctic coast. Antarctic Polar Biome Lies over landmass of the Antarctic continent. Plants - lichens, mosses, 3 types of flowering plants Animals - small insects, seals, whales, penguins.
Terrestrial Biomes TUNDRA Treeless biome blanketed by snow in winter that forms continuous belt across northern North America, Europe, and Asia Tundralike regions may also exist on mountains above treeline Highest point at which trees grow. Characterized by a Permafrost Surface soil thawed for only about 8 weeks During thaw patchwork of shallow pond, bogs, and soggy soil Climate - cold and dry Plants - mosses, lichens, dwarf woody plants – No trees Animals - Insects, ducks, geese, predatory birds, musk ox, caribou, lemmings, and weasels
Terrestrial Biomes CONIFEROUS FOREST Biome dominated by conifers Long, cold winters and short cool summers. Nutrient poor soils; usually acidic. Animals - moose, bear, lynx Northern parts of Europe, Asia, and North America Three subdivisions Taiga Coniferous Belt Southern Pine Forests
Terrestrial Biomes DECIDUOUS FOREST Characterized by trees that lose their leaves in the fall. Definite seasons; temperate region Stretch across eastern U.S., much of Europe, part of Asia, South America, Africa, and Australia Precipitation evenly distributed over the year; Rainfall - 75 to 125 cm per year; moderately rich soil Dominant trees - birch, beech, maple, oak, hickory, elm, sycamore, willow, and cottonwood. Animals - white-tailed deer, black bear, raccoons, squirrels, hundreds of bird species