Transcript Ecosystem
Ch.9.1 Active Biology Unit Hydra Clips http://www.youtube.com/watch?fe ature=endscreen&NR=1&v=12Om szObAkM http://www.youtube.com/watch?v= G188PDx73i8 Planarian Planarian Clips http://www.youtube.com/watch?v= w0QzSYQGsnA http://www.youtube.com/watch?v= 0L_mJoG4nts Earthworm Earthworm Clips http://www.youtube.com/watch?v= bFpblBf1dfE http://www.youtube.com/watch?v= uO4lkv-jLRs Hermit Crab Hermit Crab Clips http://www.youtube.com/watch?v= DaU5etPejZA http://www.youtube.com/watch?v= CMKbJJ04rXg Frog Frog Clips http://www.youtube.com/watch?v= wXqK5QulbJ8 http://www.youtube.com/watch?v= cBkWhkAZ9ds http://www.youtube.com/watch?N R=1&v=ZUsARFCBcI&feature=endscreen Biosphere • Biosphere = the area on earth where living organisms can be found. • These are the levels of organization: – Organism – Population – Community – Ecosystem – Biome Ecosystems • Organism = a single member of a species • Population = many members of a species living together in one area • Community = groups of different species living together in one area Ecosystems • An ecosystem is the community plus all the different physical aspects of the habitat. This includes: – Abiotic (nonliving) factors such as rocks, water, weather and soil. – Biotic (living) factors, which are all the living organisms like plants, animals and bacteria. • Biodiversity describes the number of species found within an ecosystem. Desert Organism: California Quail Population: Several California Quail Community: Quail, Hare & Coyote Ecosystem: Biotic + Abiotic Factors Extinction • One last term in natural selection is extinction (when a species disappears permanently). – Most extinctions are caused by natural disasters, and/or humans. Grizzly bear still alive and found in different parts of world. Ursus horribilus California Grizzly Ursus californicus Last one shot in 1922. Keystone Species Flow of Energy • Autotrophs, or Producers, are organisms who get their energy from nonliving sources. • Heterotrophs, or Consumers, are organisms who get their energy from other living, or onceliving resources. Flow of Energy • Chemosynthesis = a process where an organism uses chemicals to make carbohydrates. • Example: CO2, H2O, H2S, O2 → Sugar Compounds Food Chains & Food Webs • Food Chains show a sequence that links species by feeding relationships. • Food Webs show complex networks of feeding relationships. Herbivores only eat plants Carnivores only eat animals Omnivores eat plants & animals Detritivores eat dead organic matter Scavengers? -Scavengers, such as vultures, are considered detritivores. Decomposers break down organic matter Trophic Levels: (nourishment or food levels) → Quaternary Consumer → Tertiary Consumer → Secondary Consumer → Primary Consumer → Producer Energy Pyramids show transfer of energy in an ecosystem. → 6 Kilocalories → 60 Kilocalories → 600 Kilocalories → 6000 Kilocalories Changing Population Sizes Rodent plague in South Australia Changing Ecosystems • Succession = the gradual and sequential replacement of populations in an area. Pioneer species = first species to colonize a new habitat. Seral community = communities that come after pioneer species that gradually replace each other. Climax community = community that remain stable as long as there is no disturbance. • Primary Succession = from nothing to life (can take a really long time) • Secondary Succession = from disruption back to life (doesn’t take as long)