Ecology and evolution Topic 5.1 Communities and ecosystems Some useful definitions: Species – A group of organisms that can interbreed and produce fertile offspring. Eg. a lion or a tiger But………A lion and a tiger can reproduce together and produce a Liger Is the liger a new species? Are lions and Tigers the same species? No, because the liger is sterile. Habitat – The environment where a species normally lives or the location of a living organism. Homework: Find out: What is a niche? How is it different from a habitat? A species share of a habitat and the resources in it. This depends not only where the organism lives but also what it does. Population – a group of organisms of the same species who live in the same area at the same time. What’s missing from this graph? .........It has area ……..it has time Community – a group of populations living and interacting with each other in an area. Ecosystem – A community and its abiotic (non-living) environment Ecology – The study of the relationships between living organisms and their relationships with the environment Living (biotic) things that affect Ecosystems Non-living (a-biotic) factors that effect Ecosystems Autotroph- An organism that synthesises its organic molecules from simple inorganic substances. A plant yesterday. Autotrophic bacteria Heterotroph – an organism that obtains organic molecules from other organisms. Saprotroph – an organism that lives on or in nonliving matter, secreting digestive enzymes into it and absorbing the products of digestion. What do you call a mushroom that buys you drinks? A Fungi to be with! Detritivore – an organism that ingests non-living organic material. A woodlouse Food chains The arrows represent the flow of energy from eaten to eater! Producer Primary consumer Secondary consumer Tertiary consumer Make food chains with the following organisms: A) Shark Minnow Zooplankton Phytoplankton Tuna B) •Lion •Gazelle •Grass •Tick •Ox-pecker (bird that eats ticks) What is the initial energy source for both chains? Make sure the arrows go in the right direction. Food webs What is the trophic level of the: Caterpillar? Primary consumer Robin? 2o, 3o, and 4o Consumer Owl? Higher Level question: What will happen to the resilience of a food web if you increase the complexity? Homework Page 176, Question 5 Using Clip art make a food web that contains at least 10 named organisms (common names are acceptable but must be more than “big fish” or “tree”!) Pyramid of numbers Pyramid of numbers An ecological pyramid of numbers shows the population of each level in a food chain in a pictorial form. ….but….. Pyramid of numbers for a tree …so we could use a pyramid of biomass Pyramid of Biomass An ecological pyramid of biomass shows what happens to the amount of biomass at each trophic level by showing how much living material there is at each trophic level of a community at a specific time. Typical units for a biomass pyramid could be grams per meter2 (gm-2), or calories per meter2(cal m-2). ….but…… Dead bird Not every part of an organism is digestable, the beak and bones of a bird will not pass on to the next trophic level. This can make a pyramid of Biomass look like it contains more energy than it actually does. …. So we could use a pyramid of productivity. An ecological pyramid of productivity is often more useful, showing the production or turnover of biomass at each trophic level. Instead of showing a single snapshot in time, productivity pyramids show the flow of energy through the food chain. Typical units would be grams per meter2 per year (g m2yr-1) or calories per meter2 per year (cal m2yr-1) As with the others, this graph begins with producers at the bottom and places higher trophic levels on top. (Wikipedia - http://en.wikipedia.org/wiki/Ecological_pyramid - 09.10 – 16th September 2010) Energy flows but Nutrients cycle Light Energy Heat Energy Nutrients An Ecosystem Bibliography • • Evolution of man picture http://daily.swarthmore.edu/static/uploads/by_date/2009/02/19/evolution.jpg Lion Picture http://bluepyramid.org/ia/lion.jpg Tiger picture http://fohn.net/tiger-pictures-facts/tiger-regal.jpg Liger picture http://img40.exs.cx/img40/8801/liger10jb.png Habitat picture http://www.desertlion.info/photos/22-wend-1c6.jpg Population graph http://www.sustainablescale.org/images/uploaded/Population/World%20Population%20Growth%20to% 202050.JPG Community picture http://media-2.web.britannica.com/eb-media/48/6548-004-4D277914.gif Ecosystem picture http://www.scienceclarified.com/images/uesc_04_img0211.jpg Tree Hugger http://www.treehuggersofamerica.org/images/tree_hugger.jpg Autotrophic bacteria http://www.college.ucla.edu/webproject/micro7/studentprojects7/Rader/pseudomo.gif A plant yesterday http://mrgrassosclass.com/images/autotroph.jpg T.rex picture http://www.biblelife.org/evolution-t-rex.jpg Mushroom picture http://www.topnews.in/health/files/mushroom.jpg Woodlice picture http://wpcontent.answers.com/wikipedia/commons/thumb/4/4b/Porcellio_scaber__male_front_2_(aka).jpg/250px-Porcellio_scaber_-_male_front_2_(aka).jpg Food chain: http://blogs.townonline.com/wellesley/wp-content/uploads/2008/07/cartoon-sun-thumb10088541.jpg http://www.selfsufficientish.com/images/appletree.gif http://bichitomalo.com/images/ist1_1035760_smiling_worm_cartoon.jpg http://www.teachmecartoons.com/images/bird-cartoon.gif http://www.floatingbanana.com/artbackwash/BlackHawk1.gif Food web http://www.cals.ncsu.edu/course/ent425/images/tutorials/ecology/trophic_levels/foodweb.gif Slide 18, 19 and 20 , - Pyramid of numbers; Pyramid of numbers for a tree; Pyramid of Biomass – http://media.tiscali.co.uk/images/feeds/hutchinson/ency/0013n049.jpg - 09.01, 16th September 2010. Slide 21 – Dead Bird - Namb Faro, http://namb-ualg.blogspot.com/2009_04_01_archive.html - 09.01, 16th September 2010.