Transcript organisms
Ecology It is the scientific study in which the relationships among living organisms and the interaction the organisms have with the environment are studied Part 1: Organisms and Their Relationships Part 2: Flow of Energy in an Ecosystem Part 3: Cycling of Matter Biosphere • The biosphere is the portion of earth in which all known life forms exist. • It occupies a thin layer of air (atmosphere), water (hydrosphere), and land (lithosphere). Biotic and Abiotic Factors First, let’s review: What is a “Living Thing”? 1. 2. 3. 4. 5. Living things need to take in energy Living things get rid of waste Living things grow and develop Living things respond to their environment Living things reproduce and pass their traits onto their offspring 6. Over time, living things evolve (change slowly) in response to their environment Biotic and Abiotic Factors Biotic • The living factors in an organism’s environment Abiotic • The nonliving factors in an organism’s environment Biotic or Abiotic? (Make a Venn Diagram with your group) • • • • • • • • • • • • • Whale Clock Water Fish Paper Glass Aluminum Wooden Ruler Sand Clouds Corpse Snail Steak • • • • • • • • • • • • • Pork Chops Salad Bread Plant Hair Finger Nails Pipe Cotton Fabric Wool Gold Plastic Grapes Air Levels of Organization We have covered very small living things. Just to review, let’s start with the cell… Cell Tissues Organs Organisms Population Biological Community Ecosystem Biome Biosphere Levels of Organization • Organism: An individual • Population: Individual organisms of a single species that share the same geographic location at the same time. • Biological Community: A group of interacting populations that occupy the same area at the same time. Levels of Organization • Ecosystem: A biological community and all of the abiotic factors that affect it. • Biome: A large group of ecosystems that share the same climate and have similar types of communities. • Biosphere: All biomes together; the Earth Ecosystem Interactions • Habitat: An area where an organism lives • Niche: The role or position that an organism has in its environment Community Interactions • Competition: More than one organism uses a resource at the same time. • Predation: The act of one organism consuming another organism for food. • Symbiosis: The close relationship that exists when two or more species live together. Symbiotic relationships • Mutualism: When both organisms benefit • Commensalism: One organism benefits, while the other is neither helped nor harmed. • Parasitism: One organism benefits at the expense of the other. Left-side IntNB Reflection • Differentiate between an organism’s habitat and niche that is found in your community. – Refer to your notes and neighbors if you need help! Flow of Energy in an Ecosystem • Autotroph: An organism that collects energy from sunlight or inorganic substances to produce food. (Producer) • Heterotroph: An organism that gets its energy requirements by consuming other organisms. (Consumer) Different types of Heterotrophs • Herbivore: Eats only plants – (Deer, rabbits, grasshoppers, etc.) • Carnivore: Prey on other heterotrophs – (Wolves, lions, cats, etc.) • Omnivore: Eat both plants and animals – (Bears, humans, mockingbirds, etc.) • Detritivore: Eat fragments of dead matter – (Worms, organisms on stream bottoms, fungi) Models of Energy Flow • Trophic Levels: Each step in a food chain or food web. – Autotrophs always make up the first trophic level in ecosystems. – Heterotrophs make up the remaining levels Models of Energy Flow • Food chains: A simple model that shows how energy flows through an ecosystem Models of Energy Flow • Food webs: A model representing the many interconnected food chains and pathways in which energy flows. How many connections can we make? Models of Energy Flow • Ecological pyramids: A diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an ecosystem. – Biomass: The total mass of living matter at each trophic level • 90% is lost at each level due to maintaining the organism. – i.e., heat, cellular repair, etc. Activity: Deadly Links (In your IntNB, record the following) • Objective: To understand how food (energy) moves through an ecosystem • My assigned role in this food chain is ____________. • I am an herbivore, omnivore, or carnivore Circle One of the above Activity: What is Biological Magnification? (In your IntNB, record the following) • Objective: To understand a process called Biological Magnification (How substances amplify as they move up the food chain) Pl an kt on ea d M in no w er Pi ck er el N ee dl ef M is er h ga ns er du ck C or m or an t Sh ee ps h W at What does your graph tell you? 30 25 20 15 10 DDT in ppm 5 0 Cycling of Matter • Cycles in the Biosphere – Natural processes cycle matter through the atmosphere – The exchange of matter through the biosphere is called the biogeochemical cycle. • Bio: Involves living things • Geo: Geological Processes • Chemical: Chemical Processes Cycling of Matter The Water Cycle Solar Energy Precipitation Movement of clouds by wind Evaporation Precipitation Transpiration from plants Percolation in soil Cycling of Matter The Water Cycle • Most precipitation falls into the ocean • Over land – approximately 90% of the water evaporates – 10% transpires from plants • Only about 2% of water is retained in a reservoir – i.e., a glacier, ice cap, aquifer or lake Cycling of Matter Carbon and Oxygen Cycles CO2 in atmosphere Burning Cellular Respiration Photosynthesis Plants, Algae & Cyanobacteria Higher level Consumers Wood & Fossil Fuels Primary Consumer Detritivores (soil microbes & others) Detritus Cycling of Matter Carbon and Oxygen Cycles • Short term cycle – Autotrophs use CO2 for Photosynthesis ____________. – Heterotrophs produce CO2 during ________ Cellular Respiration __________. Cycling of Matter Carbon and Oxygen Cycles 1. Long term cycle: Fossil Fuels – – Organic matter is buried underground and converted to peat, coal, oil or gas deposits. 5.5 billion tons are burned each year and 3.3 billion tons stay in the atmosphere, the rest dissolves in sea water* http://www.ucar.edu/ (The National Center for Atmospheric Research) Cycling of Matter Carbon and Oxygen Cycles 2. Long term cycle: Calcium Carbonate (CaCO3) – Marine animals are able to use Carbon to build their skeletal material – These organisms fall to the bottom of the ocean floor, creating limestone rock. Cycling of Matter Carbon and Oxygen Cycles • Oxygen is found in the atmosphere at a stable concentration of approximately 21%. – – • Because it is a very reactive element, it can quickly combine with other elements and disappear from the atmosphere. Some of the atmospheric oxygen (O2) finds itself lofted high into the upper reaches of the atmosphere called the stratosphere, where it is converted into Ozone (O3) Ozone serves to absorb biologically damaging ultraviolet (UV) radiation from the sun. Cycling of Matter Carbon and Oxygen Cycles • Carbon dioxide (CO2) is a greenhouse gas and traps heat in the atmosphere. • Humans have burned so much fuel that there is about 30% more Carbon Dioxide in the air today than there was about 150 years ago. • The atmosphere has not held this much Carbon for at least 420,000 years according to data from ice cores. http://www.ucar.edu/ (The National Center for Atmospheric Research) Cycling of Matter Nitrogen Cycle Nitrogen in atmosphere Plants Assimilation Nitrogen – fixing bacteria in root nodules of legumes Denitrifying Nitrates bacteria Decomposers (aerobic & anaerobic bacteria and fungi) Ammonification Ammonium (NH4+) Nitrogen – fixing bacteria in soil (NO3-) Nitrifying bacteria Nitrites (NO2-) Cycling of Matter Nitrogen Cycle • Nitrogen comprises the bulk of the atmosphere (approximately 78%). • Most of it is unusable. – – • Bacteria can release nitrogen from organic material – • • A molecule of nitrogen gas is made up of 2 atoms very tightly bound together. It takes tremendous amounts of energy, such as produced by lightning or fires, to break the bond. These bacteria also release nitrogen from organic material back into the atmosphere. Nitrogen is the one element found almost entirely in the atmosphere—there's very little on land or in the sea. Nitrogen is essential to life, a key element in proteins and DNA.