Chapter 5 – Ecosystems

cont’d

A Simple Ecosystem0 Yellowstone Park0 Hot springs!

What’s a hotspring?0A spring of naturally hot water, typically heated from

rocks and minerals under the earth’s crust.

How hot? As hot as 143 degrees !

Why is the ecosystem so simple?

0Would you like to live here???

0 Snow, burning water, acidic water, alkaline water, yikes!

0 Trophic Level 1 = photosynthetic bacteria and algae

0 Trophic Level 2 = Ephydrid flies(herbivores)

0 Trophic Level 3 = dolichopodid fly, dragonflies, wasps, spiders, tiger beetles, killdeer (carnivores)

0 Trophic level 4 = bacteria

I guess there are some Complications

0The Kildeer eats in this ecosystem and lots of other ecosystems.

0Should we consider it a total member?

More complications

0Ephydrid flies have parasites. How do we add those into the food web?

What maintains it all?

01. sunlight which provides usable energy02. constant flow of hot water which supplies chemical

elements and a habitat for bacteria and algae

Hot springs

0…only about 20 species0Still pretty complex0See page 85

Different food chains

01. Oceanic0 “pelagic”

02. Terrestrial0 land

Pelagic food chain

Phytoplankton and zooplankton

Journal of the Week -Human Role

0Should we include people within the ecosystem’s food web? That would place us within nature. Or should we place people outside of the ecosystem, thus separate from nature?

Energy Flow in Ecosystem

0Ecosystem energy flow = the movement of energy through an ecosystem from the external environment through a series of organisms and back to the external environment0 1. Food webs0 2. heat travels through air/water/convection (in

ground)

Energy flow, cont’d

0First law of thermodynamics0 Law of conservation of energy0 Energy is neither created nor destroyed, just changed

from one form to another0Second law of thermodynamics

0 No use of energy in the real world can ever be 100%0 Energy lost to heat0 Entropy energy becomes more and more disorganized

as it travels through the ecosystem