Chapter 9Biological Productivity

and Energy Flow

Case Study:

Can Enough Food be Produced for Africa???

How much can we grow???What will be our Carrying

Capacity?????

The total amt of organic matter in an ecosystem =

It increases though growth

Plants, animals and dead are all biomass

Biomass is measured in

It increases through growth.

This is

Chemoautotrophs

Bacteria that use inorganic compounds (like sulfur) to make their own food and tissues

The white-ish area is a bacterial mat feeding on methane from beneath the ocean floor.

Hydrothermal vents

Energy flow

Ecosystems are all open to energy flow

Energy in food chain heat released What is not used is lost (as heat), or stored!!!!

1. kinetic- 2. potential-

energy can move back and forth between the two

Entropy-is the measure of disorder, wasted energy - becomes more random, can be sound or light but is mostly heat, everything always moves towards entropy

The laws of thermodynamics

1st Law – conservation of energy

2nd Law- entropy increases -energy moves to a less organized form

(living cells are holding off the forces of entropy by channeling energy).

Energy flow is one way!

Energy efficiency

How efficient are orgs at using energy? Not very! Rule of thumb is:

Biomass Pyramid