Chapters 3 & 4

 Anchor: BIO.B.4.2: Describe interactions and relationships in an ecosystem ◦ BIO.B.4.2.1: Describe how energy flows through an ecosystem

 For life to continue within the ecosystem, three things must be present ◦ 1. The SUN ultimately provides nearly all energy on earth! ◦ 2. The cycling of both matter and nutrients. ◦ 3. Gravity helps to hold everything in place, including the atmosphere and helps to move nutrients through their cycles Fungi

 All things in an ecosystem can be classified as: ◦ Biotic: anything living (or once living)  Ex: ◦ Abiotic: anything nonliving (never alive)  Ex:

 Classification of Organisms ◦ Producers/Autotrophs: make their own food, usually through photosynthesis  Ex:

 Chemosynthesis: producers create food in the absence of light using hydrogen sulfide ◦ Ex: bacteria that live at deep sea vents

 Consumers/Heterotrophs: cannot make their own food ◦ Herbivores: feed on plants/producers  Also called primary consumers  Ex:

◦ Carnivores: feed on other animals  Secondary Consumers: feed on primary consumers  Ex:  Tertiary Consumers: feed on secondary consumers  Ex:

◦ Omnivores: eat both producers and consumers  Ex: raccoon, bears, rats

◦ Detritivore Consumers: feed only on DETRITUS  Detritus: parts of dead organisms, wastes of organisms  Ex: earthworms, crabs, ants ◦ Decomposers: break down organic matter so that it can be recycled  Ex. Bacteria, fungi

 How does energy MOVE through ecosystems? ◦ Energy moved in the form of “food” or organic matter ◦ Remember, energy can only flow in ONE direction  From the sun  producers  consumers

 Food chain: a series of steps where organisms transfer energy by eating and being eaten ◦ Ex: ◦ What are the limitations of a food chain?  Very simple/limited – doesn’t show all food connections in an ecosystem

 Food Webs: multiple linked food chains demonstrating the complex interactions in communities ◦ Ex:

 Trophic Levels: each step in a food chain or web ◦ Ex:  Producers = 1 st trophic level  Consumers = 2 nd, 3 rd, 4 th trophic levels

Fig 6.3 © 2005 John Wiley and Sons Publishers

Fig 6.4 © 2005 John Wiley and Sons Publishers

Fig 6.5 © 2005 John Wiley and Sons Publishers

Fig 6.6 © 2005 John Wiley and Sons Publishers

 Trophic Levels: ◦ Each consumer depends upon the trophic level below it for all energy!  Only 10% of the energy is transferred from level to level  The other 90% is used by the organisms for metabolism (respiration, movement, reproduction, growth) and given off as body heat

sun secondary consumers (carnivores) primary consumers (herbivores) producers (plants) loss of energy

only this energy moves on to the next level in the food chain 17% growth 50% waste (feces) 33% cellular respiration energy lost to daily living

 Ecological Pyramids: illustrate the relative amounts of energy or matter contained within each trophic level 1,000,000, , Numbers

 Energy Pyramids: illustrates the amount of energy (organic material), usually in kCals or Joules (J), available

 Biomass Pyramids: illustrates the total amount of living tissue in a trophic level, usually in g/unit area

 Numbers Pyramid: illustrates the actual number of individual organisms in each trophic level