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HS415 Environmental Health Seminar #2 Ecology & Life (food webs) Rules Syllabus: Read it! APA format: Google it. Discussion: must respond to both questions initial: by Sat midnight min. 100 words APA format & ref’s peer: at least 2, 50 word min. Must add to the discussion! Word Count: I am not counting, unless your post is short. Rules, cont. Please name your doc’s correctly. Ex: Name_HS415_projectname.doc yes SShore_HS415_FinalProject.doc no FinalProject.doc Rules, cont. Late policy: nothing accepted late unless Extenuating circumstances??? Try to Not get behind in class…. If you are having a problem, let me know. Grading: see the rubrics (syllabus) Exams: Nit Picky! (I did not write them) Rules, cont. I really hate to bring up this subject, but… Plagiarism…will not be tolerated. The use of Turnitin.com will be often. I suggest you read the Academic Dishonesty Policy in the Syllabus and in the Student Handbook, & look in any Unit, Academic Tools (next to the To-Do List) Ecology Ecology in Greek is “house or place to live” Study between organisms & their environment Examining how organisms interact with their environment Organisms Forms of Life which can be classified into species 5-100 million species, most are insects and microorganisms About 1.8 million named Wild & Domesticated Species Wild A species that lives in its natural environment (where it’s ancestors lived) ex: coyote Domestic A species that was removed from its natural environment and placed in an environment that supports the needs and wants of HUMANS ex: dogs & cats Some Words to Know Populations – Organisms that are part – The place where a of the same species and live in the same area of space Genetic Diversity – Each different organism has a different genetic makeup Habitat population lives. Each one can very in size and place. Biological Community – A population that consists of a variety of species that live in a particular place. One more Word Ecosystem – A community of different species interacting with other species & their non-living environment Natural or Artificial LIFE! Living things are made up of one or more cells containing DNA DNA is the instructions for making new cells and amino acids, proteins Metabolism – Chemical reaction that capture and transform matter and energy from the environment to supply the organism More LIFE Homeostasis – Maintains optimal conditions despite changes to the environment Reproduction – Asexual Single cell division (mitosis), or self fertilization – Sexual Organisms exchange gametes (meiosis) and fertilize the ova to create offspring. Earth’s Life-Support Systems Layers Core (the actual center of the earth) – Fe and Trace N – Solid & Liquid Mantle (between) – Fe, Si, O, Mg – Solid and Liquid Responsible for continental drift Crust – Fossil Fuels – Where we live Spheres Lithosphere – Upper mantle and crust Atmosphere – Thin envelope of air around the lithosphere Bio-Ecosphere – Biotic and Abiotic Habitats What is Needed to Sustain Life? One way flow of energy – EX: Sunlight through feeding cycles, then into environment and eventually back out as infrared rays Cycle of Matter and Nutrients Gravity Cycles Carbon – CO2 from the atmosphere and earth’s water. PHOTOSYNTHESIS Phosphorus – DNA transfers Nitrogen – Atmospheric N to the soil, helps with amino acids Water – Storage, evaporation, precipitation, runoff Oxygen The Sun Photosynthesis CO2 + H2O + sunlight C6H12O6 + O2 Earth gets 1 billionth of the sun’s energy 28% is reflected into space (but what about the greenhouse gas effect) .023% gets absorbed by plants Ecosystem Concepts Intro Biomes – Large Regions Characterized by features Basic Zones – Land – Ecotone (transition) Aquatic Components of an Ecosystem “tics” – Biotic – Abiotic Living part of ecosystem Non-living part of ecosystem Examples • • • • • • • • • • • • ABIOTIC Air Water Nutrients Solar Energy Precipitation Wind Altitude Latitude Frequency of Fire Nature of Soil Water Currents Concentrations Laws and Factors Law of Tolerance – The existence, abundance, and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species Limiting Factor Principle – Too much or too little of any abiotic factor can prevent growth of a species BIOTIC Autotrophs-Producers – Photosynthesis – Chemosysthesis Heterotrophs-Consumers – Herbivores-Primary – Carnivores-Secondary-Tertiary – Scavengers eat already dead animals Decomposers – Break down dead organisms into nutrients – Detritivors – Bacteria – Fungi eat dead GOAL OF ALL PRODUCERS & CONSUMERS Aerobic Respiration C6H12O6 + O2 CO2 + H2O +ENERGY In humans E= ATP (adenosine triphosphate) (notice the CO2 ?) Food Webs and Energy Flow in Ecosystems A few Definitions Trophic Level – Feeding level Biomass – Dry weight which is not counted with water because water is not a source of energy – Only small amounts of what is eaten is actually converted into biomass ENERGY Some energy is lost from trophic level to trophic level 5-20% of energy is transferred from level to level The more trophic levels the greater cumulative loss of flow (pyramid of energy flow) – The energy flow triangle shows earth could support more people if we ate grains instead of grazing animals ENERGY (cont) The energy loss is so large we can only support 45 trophic levels Gross Primary Productivity (GPP): – The rate it takes ecosystems to convert solar energy into chemical energy as biomass Net Primary Productivity (NPP): – It is what is left of the biomass after the organism has used parts of it to stay alive, and reproduce ENERGY (cont) NPP is available to other organisms as food (Net Primary Productivity) The earth’s total NPP is the upper limit determining the planets carrying capacity for all species!!!!! Most Productivity: – – – – Estuaries Swamps Marshes Tropical Rain Forest ENERGY (cont) Least Productive: – Open Ocean – Tundra – Desert 59% of NPP from Land, 41% of NPP from Water Open ocean contributes a lot to NPP but phytoplankton is not reasonably harvestable HUMANS waste 27% of potential NPP and 40% of actual Come up with an example to fill in the blocks of a food chain in two different ecosytems. Caring for the Environment It is in our own best interests to look after the world we live in. If a habitat is lost or damaged, it has an effect on everything else, even if we do not see or understand it straight away. Remember - once something becomes extinct, it’s gone forever! THATS ALL Now it’s up to you….. What are YOU going to do to help save our world and future for our children?