Review of Ecology Chap. 2.1 to 2.2

Biosphere Ecosystems Realm of ecology Communities Populations Universe Galaxies Biosphere Solar systems Planets Earth Biosphere Ecosystems Ecosystems Communities Populations Realm of ecology Organisms Communities Organ systems Organs Figure 3.2 Natural capital: levels of organization of matter in nature. Ecology focuses on five of these levels. Tissues Cells Populations Protoplasm Molecules Atoms Organisms Subatomic Particles 2

Biotic vs. Abiotic Factors: Influences on each other Biotic: Biological influences on organisms Abiotic: Physical, non-living parts of an ecosystem

Levels of Organization of the Biosphere Biosphere: All life on Earth and the parts of Earth that support life Organized into specific levels

Biosphere organization: smallest to largest Species: Similar organisms that can breed and produce fertile offspring Population: Group of individuals of the same species that live in the same area http://alumnus.caltech.edu/~kantner/zebras/pictures/zebra_b.jpg http://www.south-africa-tours-and-travel.com/images/mznp-mountain-zebras-vince-o-sullivan-mountainzebranationalpark.jpg

Biosphere organization Community: Different populations that live in the same area Ecosystem: All of the organisms that live in a place, together with their physical environment http://www.safari-guide.co.uk/images/gallery/zebra_wildebeest.jpg

Biosphere organization Biome: a group of ecosystems that share similar climate and typical organisms Biosphere: All life on Earth and parts of Earth that support life.

How this classroom fits in? Species Population Community Ecosystem Biome Temperate Deciduous Biosphere

Interactions within Communities Community: group of populations in a given place and time Populations within a community can interact in manner that is beneficial or harmful http://www.mapecology.altervista.org/index_clip_image005.jpg

6 Possible Interactions + Mutualism Both helped o Commensalism One helped; one neutral Neutralism Both neutral - Amensalism One harmed; one neutral Predation (Parasitism) One helped; one harmed Competition Both harmed

Symbiosis: “Living Together” Close and established interactions among populations living in a community Include: Mutualism Commensalism Parasitism http://www.scienceclarified.com/photos/symbiosis-real-life-applications-2942.jpg

Mutualism (+/+): Both benefit Both species obtain a benefit from the relationship. Obligatory: one species is totally dependent on other Nonobligatory: can survive without relationship http://www.scienceclarified.com/photos/symbiosis-real-life-applications-2942.jpg

Commensalism (+/o): One helped; One neutral Can involve using another for: transportation (remora eel and shark), housing (Spanish moss on tree; hermit crab in old shell) to obtain food (fish and shark) http://www.bayouvermilion.org/pictures/Plants/Spanish%20Moss%20w%20Blue%20Heron%20in%20Tree.jpg http://2.bp.blogspot.com/_XMkx9D8aY_c/TRv0QDzUU-I/AAAAAAAAE3M/7G2MqueHDBo/s1600/104815-shark.jpg

Neutralism Neither affected by other Does not often occur in reality Applies when interaction is negligible

Amensalism One species suffers while the other is neutral Example: plant secretes chemical that inhibits growth around it (allelopathy)

Predation/parasitism (+/-): One is helped; one is harmed Predator = organism that is capturing and eating another Prey = organism being eaten http://per.ornl.gov/Lindroth1.jpg

Predation/parasitism (+/-): Forms of Predation Carnivory: Animal kills and eats animal Parasitism: Predator lives within host, weakens it but doesn’t kill it Parasitoidism: Lays eggs inside host and consume it as larvae grow Herbivory: Foraging on plants http://www.brotherstree.com/tick-on-skin-744826.jpg

Predator-Prey Dynamics Predators affect the size of prey populations and determine the places that prey can survive and grow. Amount of prey determine how much predator population can grow. http://braddlibby.files.wordpress.com/2010/08/lions-gazelle-1.jpg?w=425

Competition (-/-): Both harmed. Competition occurs when organisms attempt to use the same limited ecological resource in the same place at the same time Both end up in a more limited “niche” than may be possible for them without competition. http://myrmecologylab.files.wordpress.com/2010/09/3-lugubris-e-afidi-dettaglio2.jpg

Niche: How an organism “makes a living” Niche: full range of physical and biological conditions in which an organism lives and how it uses those conditions One’s niche is determined first by tolerances and habitat Tolerance: ability to survive in range of conditions Habitat: species tolerance for specific conditions determine the general place where it can live -- its “habitat.”

Niches Physical Aspects: All abiotic factors needed for survival Temperature, moisture etc. Biological Aspects: All biotic factors needed for survival How and when reproduce, food it eats, how it obtains food

Niche generalists vs. specialists Generalists: Broad niches; can live in wide range of environments (cockroaches, mice, humans) Specialists: Narrow niches; may have difficulties with environmental changes Q: Which has the advantage in a stable ecosystem?

Niches and Competition Competition can limit the niche that the species can occupy Species may be able to survive and reproduce under larger range of conditions but is limited by competition http://www.physicalgeography.net/fundamentals/images/niche.gif

Competitive Exclusion Principle No two species can occupy the same niche in the same habitat at exactly the same time The better competitor excludes the weaker one

Dividing Resources Competition is niche overlap Each species uses a portion not able to be used by another species. Competition helps determine species and niches each species occupies.