What Shapes an Ecosystem? Abiotic and Biotic Factors, Community Interactions • Write “Updates to 90-93 and Food Web Notes” on new page – Record clarifying info about pages 90-93 (part 1 – minimal notes) – Takes notes on food webs (part 2) – USE YOUR NOTES TODAY TO ANSWER QUESTIONS! The “niche” • What is a niche? – Full range of abiotic and biotic conditions in which an organism lives – and how it uses these conditions – Biotic = living – Abiotic = nonliving Niche example • Example: cane toad niche – How the cane toad interacts with all biotic/abiotic factors – for example: • Bodies of water cane toads inhabit as tadpoles • What shelter they use on land as adults • The climate/type of ecosystem they survive in best • How/when they reproduce • What they eat and what eats them • Etc… • Note: no two species occupy the same exact niche! Brainstorm: why not? • Competition! One species wins, one loses (leaves the niche, evolves, or goes extinct) eventually – might take time Competition • Could be competition for ANY type of resource – Sun, water, food, space, nutrients, etc… • What is it? What is an example in your ecosystem jar? • Record ecosystem jar example Predation • Predation: An interaction in which one organism captures and feeds on another organism. • What is it? What is an example in your ecosystem jar? • Record ecosystem jar example Symbiosis • Symbiotic relationship – A relationship in which two species live closely together. • 3 main classes of symbiosis – what are they? – Mutualism – Commensalism – Parasitism Mutualism • What is it? What is an example in your ecosystem jar? • Mutualism: Win-Win • Example: Shrew Loo • Record ecosystem jar example Commensalism • What is it? What is an example in your ecosystem jar? • Commensalism: Win-neutral • Example: Anemonefish • Record ecosystem jar example – Snails laying eggs on Elodea Parasitism • What is it? Is there an example in your ecosystem jar? • Symbiosis – when one species benefits and other is harmed – but not really predation (win-lose) – Differs in that parasites often live in or on the host • Example: Parasitic wasp Food Webs (new notes!) • Usually represent predation in an ecosystem – Show how biomass & energy move in ecosystems – Shows relationships between producers (autotrophs) and consumers (heterotrophs) • Why are they useful? – Orcas and salmon – enough to support Orcas? – Humans – enough food to support us? – What if organism(s) are removed? Predictions… – Easier than reading lots of papers (visual) • Example food web – ecosystem jars! – Build now – show organisms Energy in food webs (in 3-2) • Energy: ability to do work (NOT matter/material) – Light energy (helps producers create food) – Chemical energy (light converted to chem in food) – Thermal energy (chem converted to “waste” heat) • All energy begins at the producer level – Can move its way up a food web • Brainstorm – why do consumers have about 10% of the energy available from organisms they consume? • The remainder (90%) is: – 1) kept by producers – 2) lost as waste (thermal or chemical) – All life processes produce chemical and thermal waste – Show on food web now Biomass in food webs (in 3-2) • Biomass: living material in an ecosystem (in grams, usually) • All biomass begins at the producer level – Moves its way up a food web • Do consumers retain all biomass they consume? • No –Only about 10% gets to next level (rest is kept or lost as waste – liquid, solid, gaseous) – Show on food web now Energy vs. Matter • Energy is NOT matter – Energy is stored in matter, can be released as matter is broken down/metabolized – Plants store energy by making glucose/food – All organisms use/release energy by consuming/breaking down food