1. Chapter 1: Nutrient Cycles and Energy Flow
Section 1.1: Sustainability

2. Newfoundland’s Cod Fishery
1968: >3X pre-1950 landings
Early 1950s: Factory Fishing
: Cod moratorium

4. Sustainable Ecosystems
Ecosystem: all of the interacting parts of a biological (living) community and its environment.
“eco”  greek for home.
What happened on Easter Island?
When we talk about having sustainable ecosystems what do we mean?

5. Sustainable Ecosystems cont’d
Having a sustainable ecosystem means that it endures and supports the many organisms living in it.
Many organisms require more than one ecosystem for survival. An example of this would be any migrating animal (i.e., Canada goose flying from Toronto to S. America in the fall).

6. Parts of an Ecosystem
Ecosystems can be very large (e.g., deciduous forests of S. Ontario) or very small (e.g., rotting log).
Regardless of size, every ecosystem has biotic and abiotic parts.
Biotic: refers to the living parts of an ecosystem. These include:
Abiotic: refers to the non-living parts of an ecosystem. These include:

7. Biotic Components Producers: any organism capable of photosynthesis.
E.g. plants and algae.
All producers are autotrophs because they can produce their own energy.

8. Consumers: any organism that consumes other living things organisms.
E.g. insects and animals.
All consumers are heterotrophs because they obtain energy from other sources.
Consumers can be:
Herbivores: consume plants only
Carnivores: consume insects and/or animals only.
Omnivores: consume both plants and animals.

9. Decomposers: any organism that consumes non-living matter.
E.g. fungi, bacteria and some insects.
All decomposers are detritivores.

10. Food Webs
All biotic parts of an ecosystem can be arranged in a food web. Food webs show the feeding relationships between certain organisms.
Arrows are used to show relationships between predator and prey.
E.g. grasshopper vs. frog
Which organism is the predator?
Which organism is the prey?

11. These relationships can be integrated into a food web.
Which organisms are producers?
Green Plant
Which organisms are herbivores?
Goat
Eagle
Rabbit
Mouse
Which organisms are carnivores?
Jackal
Wild cat
Lion
Owl
Eagle
Snake