09.25.17 Catalyst Why is it important that nutrients cycle?

Burning of fossil fuels and wood Figure 55.14b CO2 in atmosphere Photosynthesis Photo- synthesis Cellular respiration Burning of fossil fuels and wood Phyto- plankton Consumers Figure 55.14 Exploring: Water and Nutrient Cycling Consumers Decomposition 3

Movement over land by wind Figure 55.14a Movement over land by wind Evaporation from ocean Precipitation over land Precipitation over ocean Evapotranspira- tion from land Figure 55.14 Exploring: Water and Nutrient Cycling Percolation through soil Runoff and groundwater 4

Decomposition and sedimentation Figure 55.14c N2 in atmosphere Reactive N gases Industrial fixation Denitrification N fertilizers Fixation Runoff Dissolved organic N NO3– Terrestrial cycling N2 NH4+ NO3– Aquatic cycling Denitri- fication Figure 55.14 Exploring: Water and Nutrient Cycling Decomposition and sedimentation Assimilation Decom- position NO3– Fixation in root nodules Uptake of amino acids Ammonification Nitrification NH3 NH4+ NO2– 5

Today. Review Cycles Vocab Clip Review Begin Food Web.

Energy, Mass, and Trophic Levels Autotrophs build molecules themselves using photosynthesis or chemosynthesis as an energy source Heterotrophs depend on the output of other organisms © 2011 Pearson Education, Inc.

Energy flow primary producers (autotrophs) to primary consumers (herbivores) to secondary consumers (carnivores) to tertiary consumers (carnivores that feed on other carnivores) © 2011 Pearson Education, Inc.

Microorganisms and other detritivores Secondary and tertiary consumers Figure 55.4 Sun Key Chemical cycling Energy flow Heat Primary producers Primary consumers Detritus Figure 55.4 An overview of energy and nutrient dynamics in an ecosystem. Microorganisms and other detritivores Secondary and tertiary consumers 9

Detritivores (decomposers) are consumers that derive their energy from detritus, nonliving organic matter © 2011 Pearson Education, Inc.

Trophic Structure the feeding relationships between organisms in a community It is a key factor in community dynamics Food chains link trophic levels from producers to top carnivores © 2011 Pearson Education, Inc.

A terrestrial food chain A marine food chain Figure 54.13 Carnivore Quaternary consumers Carnivore Carnivore Tertiary consumers Carnivore Carnivore Secondary consumers Carnivore Figure 54.13 Examples of terrestrial and marine food chains. Herbivore Primary consumers Zooplankton Plant Primary producers Phytoplankton A terrestrial food chain A marine food chain

Food Webs A food web is a branching food chain with complex trophic interactions © 2011 Pearson Education, Inc.

Humans Smaller toothed whales Baleen whales Sperm whales Elephant Figure 54.14 Humans Smaller toothed whales Baleen whales Sperm whales Elephant seals Crab- eater seals Leopard seals Birds Fishes Squids Figure 54.14 An Antarctic marine food web. Carniv- orous plankton Euphau- sids (krill) Cope- pods Phyto- plankton

Trophic Efficiency and Ecological Pyramids Trophic efficiency is the percentage of production transferred from one trophic level to the next It is about 10% © 2011 Pearson Education, Inc.

Tertiary consumers 10 J Secondary consumers 100 J Primary consumers Figure 55.11 Tertiary consumers 10 J Secondary consumers 100 J Primary consumers 1,000 J Primary producers Figure 55.11 An idealized pyramid of net production. 10,000 J 1,000,000 J of sunlight 16

Big ideas overview. Clip Now – MN Food Webs