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Mon. Tues. Wed. Thurs. Fri. Week of Oct. 6 Week of Oct. 13 No labs – Fall Break Week of Oct. 20 Class in Library Multimedia Room Wet, muddy outdoor lab – wear closed-toed shoes Week of Oct. 27 Independent project set-up

Outline for ecosystems Introduction How does energy move through an ecosystem? How does matter move through an ecosystem?

How does matter move through an ecosystem? Matter = elements e.g., what are ways that a carbon atom moves from one compartment of an ecosystem to another? How fast do carbon atoms move from one compartment to another?

Organisms move elements through chemical transformations inorganic C organic C

Figure 7.1 organic organic inorganic inorganic

Figure 7.2

How does matter move through an ecosystem? Cycles between inorganic and organic forms and between different compartments of ecosystems Difference between matter and energy movement?

Figure 7.3

Cycles of matter water carbon nitrogen phosphorus sulfur Focus on important pools and transfers

Water cycle Figure 7.4

C cycle Figure 7.5 Carbon cycle

Figure 7.6 Biological transformations of carbon

Fig. 7.11 N cycle

Figure 7.11b inorganic forms used by plants e.g., proteins Biological transformations of nitrogen

P cycle Figure 7.13

Figure 7.14a S cycle

Figure 7.14b Biological transformations of sulfur

What do I expect you to know about element cycles? • - which forms are available to bacteria, plants, • and animals • which transfers are changes in form of the • element • which transfers are biological transfers vs. • chemical or physical transfers

How does matter move through an ecosystem? Nutrient recycling in terrestrial and aquatic ecosystems

Nutrient recycling in terrestrial systems - where is it happening?

Nutrient recycling in terrestrial systems - new weathering of bedrock provides small amount of nutrients taken up by vegetation each year (~10%) - how do we know that?

-mass balance • inputs = outputs • weathering + precipitation =loss in streams calculate by difference measure

Organic matter decomposition • Leaching of soluble compounds by water • Consumption by detritus-feeding orgs. • e.g., earthworms, millipedes, etc. • Breakdown of rest by fungi and bacteria • - how do they decompose? • What factors affect rate of decomposition?

Effect of rainfall on rate of leaf decomposition

Which column is larger? Tropical Temperate Litter/living leaf Soil P/plant P Soil N/plant N %of total org C

Land use affects phosphorus retention in a system

Nitrogen fixation can increase nitrogen avail. Litter quality (nitrogen content) of different tree species

Mychorrhizae increase nutrient content of plants Fig. 8.7

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